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Article

Effective One-Component Organocatalysts for Eco-Friendly Production of Cyclic Carbonates

by
Enrique Francés-Poveda
1,†,
Marta Navarro
1,†,
Monserrat Beroíza-Duhart
2,
Genesys L. Mahecha
2,
Julio I. Urzúa
3,
María Luisa Valenzuela
4,
Felipe de la Cruz-Martínez
1,
Oscar A. Douglas-Gallardo
2,
Francisca Werlinger
5,6,
Agustín Lara-Sánchez
2,* and
Javier Martínez
2,*
1
Departamento de Química Inorgánica Orgánica y Bioquímica-Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias y Tecnologías Químicas and Instituto Regional de Investigación Científica Aplicada-IRICA, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
2
Instituto de Ciencias Químicas, Facultad de Ciencias, Universidad Austral de Chile, Independencia 631, Isla Teja, Valdivia 509000, Chile
3
Centro de Materiales para la Transición y Sostenibilidad Energética, Comisión Chilena de Energía Nuclear, Ruta 68, km 20, Pudahuel, Santiago 9020000, Chile
4
Grupo de Investigación en Energía y Procesos Sustentables, Instituto de Ciencias Aplicadas, Facultad de Ingeniería, Universidad Autónoma de Chile, Av. El Llano Subercaseaux, Santiago 2801, Chile
5
Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad Santo Tomás, Valdivia 5090000, Chile
6
Facultad de Ciencias Químicas y Farmacéuticas, Departamento de Química Orgánica y Fisicoquímica, Universidad de Chile, Santiago 8380492, Chile
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Reactions 2025, 6(1), 8; https://doi.org/10.3390/reactions6010008
Submission received: 29 November 2024 / Revised: 9 January 2025 / Accepted: 9 January 2025 / Published: 13 January 2025
(This article belongs to the Special Issue Cycloaddition Reactions at the Beginning of the Third Millennium)
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Abstract

:
One-component or bifunctional organocatalysts are some of the most capable compounds to perform the synthesis of cyclic carbonates from epoxides and carbon dioxide (CO2) since the presence of a co-catalyst is not required. In this study, we designed, synthesized, and evaluated five halogenated compounds as bifunctional organocatalysts for this catalytic transformation. Among them, 1,3-dimethylimidazolium iodide (1) exhibited the highest catalytic efficiency, enabling the synthesis of a broad range of monosubstituted cyclic carbonates with diverse functional groups under mild conditions (80 °C, 20 bar CO2) within 1 h, using only 1 mol% catalyst loading. Remarkably, this organocatalyst also facilitated the synthesis of five internal cyclic carbonates and a carvone-derived exo-cyclic carbonate, which was obtained for the first time without the use of a metal catalyst, under more demanding conditions. A mechanistic proposal was developed through a combination of 1H-NMR studies and density functional theory (DFT) simulations. Styrene oxide and cyclohexene oxide were used as model substrates to investigate the reaction pathway, which was computed using an optimized climbing-image nudged elastic band (CI-NEB) method. The results revealed the critical role of 1,3-dimethylimidazolium iodide in key reaction steps, particularly in facilitating the epoxy ring opening process. These findings highlight the potential use of bifunctional compounds as efficient and versatile catalysts for CO2 valorization.

Graphical Abstract

1. Introduction

In recent decades, atmospheric carbon dioxide (CO2) levels have steadily increased significantly, mainly due to the unconscious use of non-renewable energy sources for different human activities [1,2]. The atmospheric CO2 levels are currently reaching an alarming concentration of 426.9 ppm as of June 2024. This increase is closely linked to the growing energy demand and the extensive use of fossil fuels in emerging economies (about 30GTs of CO2 are emitted to the atmosphere by these countries annually), which has contributed negatively to global warming and also potentially to climate change. Given that global energy demand is projected to continue rising, anthropogenic greenhouse gas emissions are expected to increase further. Therefore, it is imperative to prioritize the development of greener, eco-friendly synthetic processes and environmentally sustainable methodologies to mitigate or reduce CO2 emissions in the coming years [3,4,5].
The storage, capture, and utilization of CO2 have emerged as promising solutions to reduce the impact of this greenhouse gas [6]. Carbon capture and storage (CCS) technologies encompass a range of methods designed to capture CO2 from industrial processes before it is released into the atmosphere. Beyond being considered a waste product, CO2 can be reimagined as a non-flammable, non-toxic, and renewable C1 building block with significant synthetic potential [7,8]. This molecule presents enormous potential as it can be used in various organic synthetic routes to produce fuels by reduction from formic acid [9], methanol [10,11], and methane [12,13]. In addition, CO2’s versatility is evident in its reactions with amines to synthesize formamide, formamidine, and methylamine derivatives [14]. Despite its potential, the CO2 reactivity is rather limited due to its thermodynamic stability, and consequently, it is necessary to employ harder activation processes like elevated temperatures and pressures. To address these challenges, the development of efficient catalytic systems is crucial. Such systems can enhance CO2 reactivity, paving the way for its broader application in sustainable chemical synthesis [15].
In this context, the formal cycloaddition of epoxides with CO2 has appeared as an attractive strategy to obtain high-added-value products such as cyclic carbonates (Scheme 1). This reaction pathway offers an optimal reactive scheme without generating significant by-products since all reagents used are fully incorporated into the final product. The cycloaddition of epoxides with CO2 has been the focus of extensive research and investigation in recent years [16,17,18,19,20,21,22,23,24,25,26].
Cyclic carbonates are versatile products with a wide range of applications, including their use in the pharmaceutical industry, as monomers for synthesizing biobased and biodegradable polymers, and as eco-friendly solvents like ethylene and propylene carbonate [27,28,29,30]. These compounds are produced industrially on a multi-ton scale from ethylene or propylene oxide by the catalysis of quaternary ammonium salts; however, this industrial process typically requires elevated temperatures and high CO2 pressure [31,32]. To address these challenges, several catalytic systems have been developed to reduce the required temperature and pressure, including metal catalysts [33,34,35,36], organocatalysts [20,37,38,39], metal–organic frameworks (MOFs) [40,41,42,43], and ionic liquids (ILs) [44,45,46,47,48,49,50,51].
Among these catalysts, one-component or bifunctional organocatalysts are probably some of the most promising candidates to perform this catalytic transformation since the presence of a co-catalyst is not required. In addition, these types of catalysts could exhibit greater catalytic performance for the preparation of cyclic carbonates than two-component catalyst systems [20]. Another crucial aspect to consider related to these catalysts is that their synthesis must be straightforward to guarantee economic viability. This simplicity allows them to be generated on a large scale, thereby raising their potential for industrial applications.
Therefore, motivated by their remarkable catalytic performance for the formation of cyclic carbonates, this study investigated the simple synthesis of five different halogenated bifunctional organocatalysts in the catalytic transformation of CO2 into cyclic carbonates, utilizing a broad range of mono- and disubstituted epoxides. In addition, a combination of experimental techniques and computational simulations based on the density functional theory (DFT) method were used to characterize and identify key intermediate species involved in the catalytic cycle of this chemical transformation, providing an atomistic picture and a deeper insight into the underlying reaction mechanisms catalyzed by these one-component catalysts.

2. Materials and Methods

All chemical reagents were used as received from commercial sources without further purification. Methanol (ACS reagent, 99.8%), 1-methylimidazole (99.0%), 1,2-dimethylimidazole (97.0%), bromoethane (98.0%), 1-bromobutane (99.0%), triethylamine (99.0%), pyridine (ACS reagent, 99.0%), and hydrobromic acid (ACS reagent, 48%) were obtained from Merck S.A. All reactions involving CO2 were performed in a stainless-steel reactor equipped with a magnetic stir bar. Solvents, including acetonitrile (CH3CN), hexane, and EtOAc, were pre-dried over sodium wire.
Deuterated solvents were stored over activated 4 Å molecular sieves and degassed by multiple freeze–thaw cycles. 1H and 13C{1H} NMR spectra were recorded on a Varian Inova FT-500 spectrometer and referenced to the corresponding deuterated solvent. Chemical shifts are reported in parts per million (ppm) relative to TMS [1H and 13C, δ(SiMe4) = 0]. All coupling constants (J) are given in Hz. Signal multiplicities are denoted as brs (broad singlet), s (singlet), d (doublet), t (triplet), dd (double doublet), and m (multiplet).

2.1. General Procedure for the Synthesis of Organocatalysts 1–5

Most of the catalysts used in this work are commercially available; however, we opted to prepare them through simple reactions to make the process more economically viable. It is worth highlighting that our research group has extensive experience in the quaternization of nitrogen atoms for the preparation of one-component catalysts. Consequently, for the synthesis of organocatalysts 1–5 (Figure 1), we employed methodologies similar to those previously reported by our research group [52,53]. Compounds 1–5 were characterized using NMR spectroscopy to confirm their structure and purity. Detailed synthesis procedures are provided in the Supplementary Materials.

2.2. General Procedure to Optimize Reaction Conditions for the Preparation of Styrene Carbonate

Styrene oxide (Figure 2, structure 6a) along with the synthesized bifunctional organocatalysts 1–5 was added to a 30 mL stainless-steel reactor equipped with a magnetic stir bar. The reaction mixture was stirred at 80 °C under a CO2 pressure of 20 bar for a period of between 1 and 2 h. The conversion of styrene oxide (6a, Figure 2) into styrene carbonate (7a, Figure 2) was determined by 1H-NMR spectroscopy.

2.3. General Procedure for the Synthesis of Cyclic Carbonates

To synthesize the different cyclic carbonates, the respective epoxide (1.7 mmol) molecule and one-component organocatalyst 1 (17.0–85.0 μmol) were placed in a 100 mL stainless-steel 4790 Parr reactor equipped with a magnetic stir bar and connected to a high-pressure CO2 line. The reaction mixture was heated to 80–100 °C using a Radleys TECH stirring hot plate and pressurized to 20 bar CO2 with stirring maintained for 1–72 h. After the designated time, the reactor was cooled down to room temperature over 1 h, and the pressure was gradually released through controlled depressurization. The conversion of the epoxide to the corresponding cyclic carbonate was determined by 1H-NMR spectroscopy. The remaining reaction mixture was filtered through a plug of silica, eluting with CH2Cl2 to remove the catalyst. The eluent was then concentrated under reduced pressure to obtain either pure cyclic carbonate or a mixture of cyclic carbonate and unreacted epoxide. If necessary, the mixture was further purified by flash chromatography using a gradient solvent system involving hexane, followed by hexane/EtOAc (9:1), hexane/EtOAc (6:1), hexane/EtOAc (3:1), hexane/EtOAc (1:1), and finally pure EtOAc, to isolate the pure cyclic carbonate.

2.4. Computational Details

All the computational calculations were carried out by using ORCA quantum chemistry package (version 5.0.4) [54,55]. The electronic structure of the selected molecular models was described at B3LYP [56] and ma-def2-svp [57] level including dispersion effects through the D4 Grimme scheme [58]. The computed reactive path corresponded to the minimum energy path (MEP) that connected reactive and product configuration states. A converged MEP was obtained by using a modified and efficient climbing-image nudged elastic band (CI-NEB) method implemented in ORCA package called NEB-TS [55,59]. This method combines a versatile CI-NEB with an efficient transition state searcher and it has been widely tested on several chemical reactions [59]. IDDP method was used to interpolate the initial images to start MEP convergence and TS searching process. All the found stationary points and transition states were extensively verified by performing frequency analysis calculations. To refine the obtained energies at B3LYP-D4 [60,61] def2-svp level, a set of single-point calculations on the found stationary points and transition states were computed by using both a range-separated hybrid functional ωB97X-D4 and a post-Hartree–Fock method, DLPNO-CCSD(T) [62,63,64], along with a larger basis set, def2-tzvpp. PBE0 [65] was also included as an alternative hybrid functional in our performance analysis.

3. Results and Discussions

3.1. Catalytic Yield Results for the Preparation of Different Cyclic Carbonates

Once the compounds 1–5 (Figure 1) were synthesized, we evaluated their potential use as bifunctional organocatalysts for the synthesis of cyclic carbonates via CO2 fixation into a diverse range of epoxide substrates.
First, the catalytic activity of synthesized compounds 1–5 was evaluated using styrene oxide (6a) as the model substrate to characterize this chemical reaction. The reactions were performed at 80 °C and 20 bar CO2 pressure for 2 h under solvent-free conditions. Under these experimental conditions, the corresponding styrene carbonate (7a) was obtained quantitatively (Table 1, entries 1–5). Following these initial results, we decided to reduce the molar ratio of catalysts 1–5 from 5 to 1 mol% (Table 1, entries 6–10), and the best results were achieved for halogenated catalysts 1 and 5, probably due to their higher solubility in the epoxide. To identify the most active catalyst, the reaction time was further reduced to 1 h, and iodide derivative 1 exhibited the highest performance for styrene carbonate formation under the given conditions (Table 1, entry 11). Notably, our research group had previously observed higher catalytic activity for iodide-based bifunctional organocatalysts compared to their bromide counterparts [22,23,66,67]. Finally, we conducted an additional experiment in the absence of the catalyst (Table 1, entry 13); however, the reaction did not proceed, indicating that the catalyst is essential for this catalytic process.
We subsequently carried out the chemical conversion of nine monosubstituted epoxides (6a–i) into their corresponding cyclic carbonates (7a–i), also using catalyst 1, under the same reaction conditions as previously described (see Figure 2). The formation of cyclic carbonates was confirmed through 1H-NMR spectroscopy, and the reactions were conducted in a stainless-steel reactor (see Section 2 for details). As shown in Figure 2, the epoxides were converted to their respective cyclic carbonates at moderate-to-excellent yields. Notably, no polycarbonate synthesis was observed under these conditions, resulting in high selectivity by exceeding 99% for cyclic carbonate formation.
Catalyst 1 proved to be very effective in producing various cyclic carbonate with different functional groups, including aryl (7a), chloride (7d), alcohol (7e), ether (7f and 7i), alkyne (7g), and alkene (7h), within 1 h. However, the synthesis of alkyl cyclic carbonate derivatives (7b and 7c) required 2 h to achieve satisfactory yields (Figure 2). The preparation of cyclic carbonate 7i is particularly significant as it can be used to produce non-isocyanate polyurethanes (NIPUs) by its reaction with diamines [68,69,70,71]. These results demonstrate that catalyst 1 is compatible with a wide range of functional groups and is effective in promoting the synthesis of a variety of cyclic carbonates.
The catalytic efficiency of catalyst 1 was further investigated through the use of internal epoxides (Figure 3), which are typically more challenging to convert into cyclic carbonates compared to monosubstituted epoxides. To achieve high conversions, we applied more extreme reaction conditions (100 °C; 20 bar of CO2 pressure for 24 h). We were pleased to discover that organocatalyst 1 facilitated the formation of a diverse range of disubstituted cyclic carbonates in good-to-excellent yields, with selectivities exceeding 99%, even for cyclohexene oxide (8a), a substrate prone to polycarbonate formation. Cyclohexene (9a) and cyclopentene carbonate (9b) were isolated in good yields of 75% and 93%, respectively, from their corresponding internal epoxides in the presence of 2 mol% of catalyst 1. The synthesis of 3-vinyl cyclohexene carbonate (9c) was also performed with excellent performance. It is important to point out that a mixture of diastereoisomers was observed for this cyclic carbonate, as evidenced by the presence of two carbonyl group signals in its corresponding 13C{1H}-NMR spectrum (Figure S34). Trans-4,5-dimethyl-1,3-dioxolan-2-one (9d) and trans-stilbene carbonate (9e) were isolated with lower yields. NMR spectroscopy confirmed that cyclic carbonates 9a–e were formed with the retention of epoxide stereochemistry, though a small amount (4%) of the cis-isomer was detected in the synthesis of cyclic carbonate 9d (see the Supplementary Materials for details).
After demonstrating the effectiveness of catalyst 1 in the preparation of mono- and disubstituted cyclic carbonates, we turned our attention to the synthesis of a terpene-based product, the carvone-derived exo-cyclic carbonate (11) from the substituted epoxide (10) obtained from biomass. This particular cyclic carbonate has been scarcely reported in the literature (Scheme 2) [17,72,73]. It is interesting to point out that this was the first reported instance of an organocatalyst being used to synthesize this compound. The reaction was conducted at 100 °C and 20 bar of CO2 for 72 h using a catalyst loading of 5 mol%, resulting in an impressive 95% yield. Compound 11 was purified by column chromatography and isolated as a mixture of two diastereoisomers in nearly equal proportions (see Figure S39 for further details).
After studying the formation of various cyclic carbonates, our next challenge was to elucidate the reaction mechanism. To this end, we investigated the interactions between the bifunctional catalyst 1, styrene oxide (6a), and CO2 using spectroscopy in CDCl3 with a Young-valve NMR tube (Figure 4). Initially, we focused on the potential interaction between the hydrogen atom (Ha in Figure 4a) of catalyst 1 and the oxygen atom of styrene oxide 6a as this Ha, which bridges the two nitrogen atoms of the imidazole ring, is highly acidic. As shown in Figure 4b, the signal for Ha at 10.02 ppm was significantly broadened, suggesting a strong interaction between catalyst 1 and styrene oxide. Notably, the ring-opening of the epoxide did not occur in the absence of CO2 (Figure 4b), even when the sample was subjected to elevated temperatures (80 °C) and extended reaction times (16 h). However, the addition of CO2 to the reaction mixture resulted in the formation of styrene carbonate 7a (Figure 4c).

3.2. Reactive Path Computed at DFT Level

Once we identified that 1,3-dimethylimidazolium iodide (catalyst 1, Figure 1) turned out to be the best catalyst to convert different epoxide substrates to their respective cyclic carbonates, we explored the underlying molecular mechanism using computational simulation based on the density functional theory (DFT) method. Styrene (6a) and cyclohexene (8a) oxides were selected as molecular models of mono- and disubstituted epoxide substrates, respectively, to explore this chemical transformation. To determine the molecular mechanisms that connect each selected epoxide substrate with its respective cyclic carbonate (6a to 7a and 8a to 9a), we computed the minimum energy path (MEP) along the potential energy surface (PES) for each molecular system (see Figure 5) through an efficient and modified climbing-image nudged elastic band (CI-NEB) method implemented in ORCA called NEB-TS [55,59]. This method needs, as input data, the initial and final configuration states to connect them through a set of images (or configuration) that are initially interpolated and used to find potential intermediate and transition states species along the PES. The initial configuration state was built including the epoxy substrate molecule along with the CO2 and the selected organocatalyst (see structure A, Figure 6 and Figure 7, respectively). On the other hand, the final configuration state was built by modifying the initial configuration state coordinates necessary to generate the respective cyclic carbonate (see structure D, Figure 6 and Figure 7). Both ending (or extreme) points for each system were then optimized at the B3LYP ma-def2-svp D4 level. The final MEP for each system was obtained after a set preliminary NEB-TS calculation (see the preliminary NEB-TS rounds in the Supplementary Materials). The respective energetic profile on the final MEP associated with each reactive system is shown in Figure 5, in the left and right panels, respectively. Both profiles were characterized by the presence of two intermediate species (structure B and C, Figure 5) and three transition states (structure I, II, III, Figure 5). Specifically, the relative activation barriers computed at B3LYP-D4 def2-svp for the styrene oxide transformation were 29.14, 9.93 kcal mol−1, and 11.96 kcal mol−1, respectively. Furthermore, the relative activation barrier computed at B3LYP-D4 def2-svp for the cyclohexene oxide transformation were 28.32, 20.50, and 12.81 kcal mol−1, respectively (see Table S1; for more details, see the Supplementary Materials). For both systems, the computed reaction energy was negative (exothermic) at −17.95 kcal mol−1 (styrene oxide) and −19.30 kcal mol−1 (cyclohexene oxide) with the highest energy barrier computed for the first step associated with the ring-opening process.
In order to obtain more accurate activation barriers for this chemical transformation, a refinement procedure was carried out by computing single-point (SP) energies at the ωB97x-D4 and DLPNO-CCSD(T) levels on the obtained stationary and transition-state structures at the B3LYP D4 def2-svp level. Additionally, PBE0 was also incorporated as an alternative hybrid functional to our performance analysis. All these methods confirmed that the first step still exhibited the highest energy barrier (see Tables S2 and S3 in the Supplementary Materials for more details). The refined activation energies for styrene and cyclohexene oxide’s transformation to their respective cycle carbonates at the DLPNO-CCSD(T) level turned out to be 30.36, 10.64, and 16.79 kcal mol−1 and 31.97, 23.03, and 19.37 kcal mol−1, respectively.
The sequence of elementary reaction steps associated with the final MEP for both molecular systems is shown in Figure 6 and Figure 7, respectively. In both cases, the computed reactive mechanism was characterized by an initial epoxy ring opening process assisted by both parts of bifunctional catalyst 1: iodine anion and the imidazolium ring. Firstly, the iodine anion attacked the epoxy ring, causing its opening, which was simultaneously assisted by the transference of the acidic proton located between the two nitrogen atoms of the imidazole ring to the oxygen atom of the epoxide, generating the first hydroxylated intermediate species (structure B, Figure 6 and Figure 7). Then, the protonation state of the imidazoline ring was restored by acquiring its acidic proton, resulting in the formation of a negatively charged alkoxide intermediate. This intermediate could then interact with a CO2 molecule, leading to the generation of a new carbonate species: the second intermediate (structure C, Figure 6 and Figure 7). Finally, the carbonate intermediate attacked the epoxy carbon atom, releasing the iodine anion to produce the final product: the respective cyclic carbonate. The reactive paths computed for both substrates followed similar intermediates and transition states, showing that this computed mechanism is general for mono- and disubstituted epoxide substrates. It is important to highlight that the key role of the organocatalyst predicted by computational simulation was in good agreement with the 1H-NMR experimental measurement (H broadening signal, Figure 4b) about the acidic proton along with the reaction path.
Another notable aspect of the computed reaction pathway is the degree of CO2 activation. A straightforward way to evaluate this is by analyzing the CO2 bond angle. This geometric parameter provides insight into the extent of CO2 activation and offers a rough estimation of its interaction with the substrate. Bond angles near to a linear configuration (~180°) are indicative of weak interactions while lower angles (below ~150°) may be associated with stronger interactions. Figure 6 and Figure 7 also trace the CO2 bond angle along the path on the key found structures: stationary points (A, B, C, and D) and transition states (I, II, and III). Initially, the CO2 molecule showed a weak interaction with the epoxy oxygen atom along the first step of the reactive path (A-to-B step). Then, the interaction became stronger, modifying its angle from ~176 to 132.1 (B-to-C step) when was incorporated as a carbonate group in structure C. Finally, the CO2 bond angle was modified to its final geometry when the cyclic carbonate (B-to-C step) was formed.
Based on the previous theoretical findings, we propose a mechanism for the synthesis of cyclic carbonates catalyzed by organocatalyst 1 in the reaction between epoxides and CO2 (Scheme 3). Initially, the epoxide is activated by hydrogen bonding between its oxygen atom and the acidic hydrogen atom from the imidazole ring. This activation assists the nucleophilic attack of the iodide on the epoxide, opening the ring and forming an iodide–alcohol intermediate. Subsequently, the latter transfers a proton to the imidazole, regenerating the catalytically active species and forming an alkoxide group. Finally, CO2 is inserted to form a carbonate intermediate, which quickly cyclizes to obtain the cyclic carbonate.

4. Conclusions

In summary, a set of five catalysts were synthesized and assessed to activate the cycloaddition of epoxides with CO2 to prepare cyclic carbonates under solvent-free conditions. Among them, 1,3-dimethylimidazolium iodide (1) showed the best performance for this reaction, allowing the formation of a wide variety of monosubstituted cyclic carbonates (7a–i) in excellent yields under relatively moderate reaction conditions (80 °C, 20 bar, 1 h, and 1 mol% of catalyst loading). In addition, this catalyst was also able to prepare disubstituted cyclic carbonates (9a–e) using more extreme reaction conditions (100 °C, 20 bar, 24 h, and 2 mol% of catalyst loading). It is interesting to point out that in this contribution, the synthesis of the carvone-derived cyclic carbonate 11 was carried out for the first time using an organocatalyst.
1H-NMR experiments and computational studies were performed to elucidate the reaction mechanism, employing styrene and cyclohexene oxide as model substrates. In conclusion, it is possible to attribute the highlighted catalytic activity of organocatalyst 1 to its special molecular structure characterized by its acidic proton along with the iodine anion, which was able to activate the epoxy ring opening process, reducing the activation barrier for this chemical transformation.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/reactions6010008/s1, Figure S1: 1H-NMR spectrum of 1,3-dimethylimidazolium iodide 1 in CDCl3; Figure S2. 13C{1H}-NMR spectrum of 1,3-dimethylimidazolium iodide 1 in CDCl3; Figure S3. 1H-NMR spectrum of triethylammonium bromide 2 in CDCl3; Figure S4. 13C{1H}-NMR spectrum of triethylammonium bromide 2 in CDCl3; Figure S5. 1H-NMR spectrum of pyridinium bromide 3 in CDCl3; Figure S6. 13C{1H}-NMR spectrum of pyridinium bromide 3 in CDCl3; Figure S7. 1H-NMR spectrum of 3-ethyl-1,2-dimethyl-1H-imidazol-3-ium bromide 4 in CDCl3; Figure S8. 13C{1H}-NMR spectrum of 3-ethyl-1,2-dimethyl-1H-imidazol-3-ium bromide 4 in CDCl3; Figure S9. 1H-NMR spectrum of (1-butyl)triethylammonium bromide 5 in CDCl3; Figure S10. 13C{1H}-NMR spectrum of (1-butyl)triethylammonium bromide 5 in CDCl3; Figure S11. 1H-NMR spectrum of 4-phenyl-1,3-dioxolan-2-one 7a in CDCl3; Figure S12. 13C{1H}NMR spectrum of 4-phenyl-1,3-dioxolan-2-one 7a in CDCl3; Figure S13. 1H-NMR spectrum of 4-methyl-1,3-dioxolan-2-one 7b in CDCl3; Figure S14. 13C{1H}NMR spectrum of 4-methyl-1,3-dioxolan-2-one 7b in CDCl3; Figure S15. 1H-NMR spectrum of 4-butyl-1,3-dioxolan-2-one 7c in CDCl3; Figure S16. 13C{1H}NMR spectrum of 4-butyl-1,3-dioxolan-2-one 7c in CDCl3; Figure S17. 1H-NMR spectrum of 4-(chloromethyl)-1,3-dioxolan-2-one 7d in CDCl3; Figure S18. 13C{1H}NMR spectrum of 4-(chloromethyl)-1,3-dioxolan-2-one 7d in CDCl3; Figure S19. 1H-NMR spectrum of 4-(hydroxymethyl)-1,3-dioxolan-2-one 7e in CDCl3; Figure S20. 13C{1H}NMR spectrum of 4-(hydroxymethyl)-1,3-dioxolan-2-one 7e in CDCl3; Figure S21. 1H-NMR spectrum of 4-(phenoxymethyl)-1,3-dioxolan-2-one 7f in CDCl3; Figure S22. 13C{1H}NMR spectrum of 4-(phenoxymethyl)-1,3-dioxolan-2-one 7f in CDCl3; Figure S23. 1H-NMR spectrum of 4-((prop-2-yn-1-yloxy)methyl)-1,3-dioxolan-2-one 7g in CDCl3; Figure S24. 13C{1H}NMR spectrum of 4-((prop-2-yn-1-yloxy)methyl)-1,3-dioxolan-2-one 7g in CDCl3; Figure S25. 1H-NMR spectrum of 4-((allyloxy)methyl)-1,3-dioxolan-2-one 7h in CDCl3; Figure S26. 13C{1H}NMR spectrum of 4-((allyloxy)methyl)-1,3-dioxolan-2-one 7h in CDCl3; Figure S27. 1H-NMR spectrum of 4-((4-((3-methylenecyclopentyl)methoxy)butoxy)methyl)-1,3-dioxolan-2-one 7i in CDCl3; Figure S28. 13C{1H}NMR spectrum of 4-((4-((3-methylenecyclopentyl)methoxy)butoxy)methyl)-1,3-dioxolan-2-one 7i in CDCl3; Figure S29. 1H-NMR spectrum of (3aR,7aS)-hexahydrobenzo[d][1,3]dioxol-2-one 9a in CDCl3; Figure S30. 13C{1H}NMR spectrum of (3aR,7aS)-hexahydrobenzo[d][1,3]dioxol-2-one 9a in CDCl3; Figure S31. 1H-NMR spectrum of (3aR,6aS)-tetrahydro-4H-cyclopenta[d][1,3]dioxol-2-one 9b in CDCl3; Figure S32. 13C{1H}NMR spectrum of (3aR,6aS)-tetrahydro-4H-cyclopenta[d][1,3]dioxol-2-one 9b in CDCl3; Figure S33. 1H-NMR spectrum of (3aR,7aS)-5-vinylhexahydrobenzo[d][1,3]dioxol-2-one 9c in CDCl3; Figure S34. 13C{1H}NMR spectrum of (3aR,7aS)-5-vinylhexahydrobenzo[d][1,3]dioxol-2-one 9c in CDCl3; Figure S35. 1H-NMR spectrum of 4,5-dimethyl-1,3-dioxolan-2-one 9d in CDCl3; Figure S36. 13C{1H}NMR spectrum of 4,5-dimethyl-1,3-dioxolan-2-one 9d in CDCl3; Figure S37. 1H-NMR spectrum of 4,5-diphenyl-1,3-dioxolan-2-one 9e in CDCl3; Figure S38. 13C{1H}NMR spectrum of 4,5-diphenyl-1,3-dioxolan-2-one 9e in CDCl3; Figure S39. 1H-NMR spectrum of 4-methyl-4-(4-methyl-5-oxocyclohex-3-en-1-yl)-1,3-dioxolan-2-one 11 in CDCl3; Figure S40. 13C{1H}NMR spectrum of 4-methyl-4-(4-methyl-5-oxocyclohex-3-en-1-yl)-1,3-dioxolan-2-one 11 in CDCl3; Table S1. Reactive and activation energies computed at DFT level for styrene and cyclohexene oxide; Figure S41. First NEB-TS calculation round for both molecular models; Figure S42. Second NEB-TS calculation round for both molecular models; Figure S43. Third NEB-TS calculation round for both molecular models; Table S2. Reaction and activation energy refinement for the styrene oxide transformation; Table S3. Reaction and activation energy refinement for the cyclohexene oxide transformation.

Author Contributions

Conceptualization, E.F.-P. and M.N.; methodology, M.B.-D. and J.I.U.; validation, J.M., F.W. and A.L.-S.; formal analysis, E.F.-P. and M.N.; investigation, E.F.-P. and M.N.; resources, J.M. and A.L.-S.; data curation, G.L.M. and O.A.D.-G.; writing—original draft preparation, O.A.D.-G. and J.M.; writing—review and editing, J.M., F.W. and A.L.-S.; visualization, M.L.V.; supervision, F.d.l.C.-M.; project administration, J.M.; funding acquisition, J.M. and A.L.-S. All authors have read and agreed to the published version of the manuscript.

Funding

We gratefully acknowledge the financial support from grants PID2020–117788RB-I00, funded by MCIN/AEI/ 10.13039/501100011033; grant RED2022–134287-T, funded by MCIN/AEI; grants SBPLY/21/180501/000132 and SBPLY/23/180225/000094, funded by Junta de Comunidades de Castilla-La Mancha and by the EU through “Fondo Europeo de Desarollo Regional” (FEDER); and grant 2021-GRIN-31240, funded by Universidad de Castilla-La Mancha. F.W. is grateful for FONDECYT Postdoctoral Fellowship 3220023. J.M. is grateful for FONDECYT Iniciación Fellowship 11230124 and FOVI230027. J.I.U. is grateful for FONDECYT Iniciación Fellowship 11220420.

Data Availability Statement

The original contributions presented in this study are included in the article/Supplementary Materials. Further inquiries can be directed to the corresponding authors.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Crippa, M.; Guizzardi, D.; Solazzo, E.; Muntean, M.; Schaaf, E.; Monforti-Ferrario, F.; Banja, M.; Olivier, J.; Grassi, G.; Rossi, S. GHG Emissions of All World Countries; Publications Office of the European Union: Ispra, Italy, 2024. [Google Scholar]
  2. NOAA’s Global Monitoring Lab National Oceanic and Atmospheric Administration Global Monitoring Lab. Available online: https://www.noaa.gov/climate (accessed on 6 August 2024).
  3. Nasirov, F.; Nasirli, E.; Ibrahimova, M. Cyclic Carbonates Synthesis by Cycloaddition Reaction of CO2 with Epoxides in the Presence of Zinc-Containing and Ionic Liquid Catalysts. J. Iran. Chem. Soc. 2022, 19, 353–379. [Google Scholar] [CrossRef]
  4. Nunes, L.J.R. The Rising Threat of Atmospheric CO2: A Review on the Causes, Impacts, and Mitigation Strategies. Environments 2023, 10, 66. [Google Scholar] [CrossRef]
  5. Anastas, P.; Eghbali, N. Green Chemistry: Principles and Practice. Chem. Soc. Rev. 2010, 39, 301–312. [Google Scholar] [CrossRef] [PubMed]
  6. Bobbink, F.D.; Dyson, P.J. Synthesis of Carbonates and Related Compounds Incorporating CO2 Using Ionic Liquid-Type Catalysts: State-of-the-Art and Beyond. J. Catal. 2016, 343, 52–61. [Google Scholar] [CrossRef]
  7. Shu, D.Y.; Deutz, S.; Winter, B.A.; Baumgärtner, N.; Leenders, L.; Bardow, A. The Role of Carbon Capture and Storage to Achieve Net-Zero Energy Systems: Trade-Offs between Economics and the Environment. Renew. Sustain. Energy Rev. 2023, 178, 113246. [Google Scholar] [CrossRef]
  8. Bahman, N.; Al-Khalifa, M.; Al Baharna, S.; Abdulmohsen, Z.; Khan, E. Review of Carbon Capture and Storage Technologies in Selected Industries: Potentials and Challenges. Rev. Environ. Sci. Bio/Technol. 2023, 22, 451–470. [Google Scholar] [CrossRef]
  9. Ewis, D.; Arsalan, M.; Khaled, M.; Pant, D.; Ba-Abbad, M.M.; Amhamed, A.; El-Naas, M.H. Electrochemical Reduction of CO2 into Formate/Formic Acid: A Review of Cell Design and Operation. Sep. Purif. Technol. 2023, 316, 123811. [Google Scholar] [CrossRef]
  10. Hussain, I.; Alasiri, H.; Khan, W.U.; Alhooshani, K. Advanced Electrocatalytic Technologies for Conversion of Carbon Dioxide into Methanol by Electrochemical Reduction: Recent Progress and Future Perspectives. Coord. Chem. Rev. 2023, 482, 215081. [Google Scholar] [CrossRef]
  11. Wiranarongkorn, K.; Eamsiri, K.; Chen, Y.-S.; Arpornwichanop, A. A Comprehensive Review of Electrochemical Reduction of CO2 to Methanol: Technical and Design Aspects. J. CO2 Util. 2023, 71, 102477. [Google Scholar] [CrossRef]
  12. Faria, A.C.; Trujillano, R.; Rives, V.; Miguel, C.V.; Rodrigues, A.E.; Madeira, L.M. Cyclic Operation of CO2 Capture and Conversion into Methane on Ni-Hydrotalcite Based Dual Function Materials (DFMs). J. CO2 Util. 2023, 72, 102476. [Google Scholar] [CrossRef]
  13. Ren, J.; Lou, H.; Xu, N.; Zeng, F.; Pei, G.; Wang, Z. Methanation of CO/CO2 for Power to Methane Process: Fundamentals, Status, and Perspectives. J. Energy Chem. 2023, 80, 182–206. [Google Scholar] [CrossRef]
  14. Tlili, A.; Blondiaux, E.; Frogneux, X.; Cantat, T. Reductive Functionalization of CO2 with Amines: An Entry to Formamide, Formamidine and Methylamine Derivatives. Green Chem. 2015, 17, 157–168. [Google Scholar] [CrossRef]
  15. Tao, D.-J.; Qu, F.; Li, Z.-M.; Zhou, Y. Promoted Absorption of CO at High Temperature by Cuprous-Based Ternary Deep Eutectic Solvents. AIChE J. 2021, 67, e17106. [Google Scholar] [CrossRef]
  16. Yan, T.; Liu, H.; Zeng, Z.X.; Pan, W.G. Recent Progress of Catalysts for Synthesis of Cyclic Carbonates from CO2 and Epoxides. J. CO2 Util. 2023, 68, 102355. [Google Scholar] [CrossRef]
  17. Martínez, J.; de la Cruz-Martínez, F.; Martínez de Sarasa Buchaca, M.; Fernández-Baeza, J.; Sánchez-Barba, L.F.; North, M.; Castro-Osma, J.A.; Lara-Sánchez, A. Efficient Synthesis of Cyclic Carbonates from Unsaturated Acids and Carbon Dioxide and Their Application in the Synthesis of Biobased Polyurethanes. Chempluschem 2021, 86, 460–468. [Google Scholar] [CrossRef]
  18. Andrea, K.A.; Kerton, F.M. Iron-Catalyzed Reactions of CO2 and Epoxides to Yield Cyclic and Polycarbonates. Polym. J. 2021, 53, 29–46. [Google Scholar] [CrossRef]
  19. Zhang, F.; Wang, Y.; Zhang, X.; Zhang, X.; Liu, H.; Han, B. Recent Advances in the Coupling of CO2 and Epoxides into Cyclic Carbonates under Halogen-Free Condition. Green Chem. Eng. 2020, 1, 82–93. [Google Scholar] [CrossRef]
  20. Guo, L.; Lamb, K.J.; North, M. Recent Developments in Organocatalysed Transformations of Epoxides and Carbon Dioxide into Cyclic Carbonates. Green Chem. 2021, 23, 77–118. [Google Scholar] [CrossRef]
  21. Claver, C.; Yeamin, M.B.; Reguero, M.; Masdeu-Bultó, A.M. Recent Advances in the Use of Catalysts Based on Natural Products for the Conversion of CO2 into Cyclic Carbonates. Green Chem. 2020, 22, 7665–7706. [Google Scholar] [CrossRef]
  22. Martínez, J.; de la Cruz-Martínez, F.; de Sarasa Buchaca, M.M.; Caballero, M.P.; Ojeda-Amador, R.M.; Salvador, M.D.; Fregapane, G.; Tejeda, J.; Castro-Osma, J.A.; Lara-Sánchez, A. Valorization of Agricultural Waste and CO2 into Bioderived Cyclic Carbonates. J. Environ. Chem. Eng. 2021, 9, 105464. [Google Scholar] [CrossRef]
  23. Werlinger, F.; Caballero, M.P.; Trofymchuk, O.S.; Flores, M.E.; Moreno-Villoslada, I.; de la Cruz-Martínez, F.; Castro-Osma, J.A.; Tejeda, J.; Martínez, J.; Lara-Sánchez, A. Turning Waste into Resources. Efficient Synthesis of Biopolyurethanes from Used Cooking Oils and CO2. J. CO2 Util. 2024, 79, 102659. [Google Scholar] [CrossRef]
  24. Limburg, B.; Cristòfol, À.; Della Monica, F.; Kleij, A.W. Unlocking the Potential of Substrate-Directed CO2 Activation and Conversion: Pushing the Boundaries of Catalytic Cyclic Carbonate and Carbamate Formation. ChemSusChem 2020, 13, 6056–6065. [Google Scholar] [CrossRef] [PubMed]
  25. Bhat, G.A.; Darensbourg, D.J. Progress in the Catalytic Reactions of CO2 and Epoxides to Selectively Provide Cyclic or Polymeric Carbonates. Green Chem. 2022, 24, 5007–5034. [Google Scholar] [CrossRef]
  26. Zhang, Y.; Yang, G.; Xie, R.; Yang, L.; Li, B.; Wu, G. Scalable, Durable, and Recyclable Metal-free Catalysts for Highly Efficient Conversion of CO2 to Cyclic Carbonates. Angew. Chemie 2020, 132, 23491–23498. [Google Scholar] [CrossRef]
  27. Pescarmona, P.P. Cyclic Carbonates Synthesised from CO2: Applications, Challenges and Recent Research Trends. Curr. Opin. Green Sustain. Chem. 2021, 29, 100457. [Google Scholar] [CrossRef]
  28. Myri, L.; Cooper, J.F. Catalytic Process for Producing Alkylene Carbonates. U.S. Patent 2,773,070, 4 December 1956. [Google Scholar]
  29. Rollin, P.; Soares, L.K.; Barcellos, A.M.; Araujo, D.R.; Lenardão, E.J.; Jacob, R.G.; Perin, G. Five-Membered Cyclic Carbonates: Versatility for Applications in Organic Synthesis, Pharmaceutical, and Materials Sciences. Appl. Sci. 2021, 11, 5024. [Google Scholar] [CrossRef]
  30. Zhang, W.; Dai, J.; Wu, Y.-C.; Chen, J.-X.; Shan, S.-Y.; Cai, Z.; Zhu, J.-B. Highly Reactive Cyclic Carbonates with a Fused Ring toward Functionalizable and Recyclable Polycarbonates. ACS Macro Lett. 2022, 11, 173–178. [Google Scholar] [CrossRef]
  31. Peppel, W.J. Preparation and Properties of the Alkylene Carbonates. Ind. Eng. Chem. 1958, 50, 767–770. [Google Scholar] [CrossRef]
  32. Schaffner, B.; Schaffner, F.; Verevkin, S.P.; Borner, A. Organic Carbonates as Solvents in Synthesis and Catalysis. Chem. Rev. 2010, 110, 4554–4581. [Google Scholar] [CrossRef]
  33. Prasad, D.; Patil, K.N.; Chaudhari, N.K.; Kim, H.; Nagaraja, B.M.; Jadhav, A.H. Paving Way for Sustainable Earth-Abundant Metal Based Catalysts for Chemical Fixation of CO2 into Epoxides for Cyclic Carbonate Formation. Catal. Rev. 2022, 64, 356–443. [Google Scholar] [CrossRef]
  34. Della Monica, F.; Capacchione, C. Recent Advancements in Metal-catalysts Design for CO2/Epoxide Reactions. Asian J. Org. Chem. 2022, 11, e202200300. [Google Scholar] [CrossRef]
  35. Tyagi, P.; Singh, D.; Malik, N.; Kumar, S.; Singh Malik, R. Metal Catalyst for CO2 Capture and Conversion into Cyclic Carbonate: Progress and Challenges. Mater. Today 2023, 65, 133–165. [Google Scholar] [CrossRef]
  36. Al-Qaisi, F.M.; Qaroush, A.K.; Okashah, I.K.; Eftaiha, A.F.; Vasko, P.; Alsoubani, F.; Repo, T. The Use of Sustainable Transition Metals for the Cycloaddition of Epoxides and CO2 under Mild Reaction Conditions. Eur. J. Inorg. Chem. 2023, 26, e202200357. [Google Scholar] [CrossRef]
  37. Tong, H.; Qu, Y.; Li, Z.; He, J.; Zou, X.; Zhou, Y.; Duan, T.; Liu, B.; Sun, J.; Guo, K. Halide-Free Pyridinium Saccharinate Binary Organocatalyst for the Cycloaddition of CO2 into Epoxides. Chem. Eng. J. 2022, 444, 135478. [Google Scholar] [CrossRef]
  38. Zhang, F.; Bulut, S.; Shen, X.; Dong, M.; Wang, Y.; Cheng, X.; Liu, H.; Han, B. Halogen-Free Fixation of Carbon Dioxide into Cyclic Carbonates via Bifunctional Organocatalysts. Green Chem. 2021, 23, 1147–1153. [Google Scholar] [CrossRef]
  39. Ravi, S.; Kim, J.; Choi, Y.; Han, H.H.; Wu, S.; Xiao, R.; Bae, Y.-S. Metal-Free Amine-Anchored Triazine-Based Covalent Organic Polymers for Selective CO2 Adsorption and Conversion to Cyclic Carbonates Under Mild Conditions. ACS Sustain. Chem. Eng. 2023, 11, 1190–1199. [Google Scholar] [CrossRef]
  40. Pal, T.K.; De, D.; Bharadwaj, P.K. Metal–Organic Frameworks for the Chemical Fixation of CO2 into Cyclic Carbonates. Coord. Chem. Rev. 2020, 408, 213173. [Google Scholar] [CrossRef]
  41. Bondarenko, G.N.; Ganina, O.G.; Lysova, A.A.; Fedin, V.P.; Beletskaya, I.P. Cyclic Carbonates Synthesis from Epoxides and CO2 over NIIC-10 Metal-Organic Frameworks. J. CO2 Util. 2021, 53, 101718. [Google Scholar] [CrossRef]
  42. Xu, J.-H.; Peng, S.-F.; Shi, Y.-K.; Ding, S.; Yang, G.-S.; Yang, Y.-Q.; Xu, Y.-H.; Jiang, C.-J.; Su, Z.-M. A Novel Zirconium-Based Metal–Organic Framework Covalently Modified by Methyl Pyridinium Bromide for Mild and Co-Catalyst Free Conversion of CO2 to Cyclic Carbonates. Dalt. Trans. 2023, 52, 659–667. [Google Scholar] [CrossRef]
  43. Zhai, G.; Liu, Y.; Lei, L.; Wang, J.; Wang, Z.; Zheng, Z.; Wang, P.; Cheng, H.; Dai, Y.; Huang, B. Light-Promoted CO2 Conversion from Epoxides to Cyclic Carbonates at Ambient Conditions over a Bi-Based Metal–Organic Framework. Acs Catal. 2021, 11, 1988–1994. [Google Scholar] [CrossRef]
  44. Norouzi, F.; Abdolmaleki, A. CO2 Conversion into Carbonate Using Pyridinium-Based Ionic Liquids under Mild Conditions. Fuel 2023, 334, 126641. [Google Scholar] [CrossRef]
  45. Jiang, Y.; Wang, D.; Guo, B.; Zhao, J.; Zhou, Z.; Jin, L.; Lei, Y. Chemical Fixation of Carbon Dioxide into Cyclic Carbonates by Multi-Hydroxyl Carboxylic Acid Ionic Liquids under Atmospheric Pressure. Mol. Catal. 2023, 551, 113664. [Google Scholar] [CrossRef]
  46. Zhao, T.; Long, G.; Liang, H.; Xiong, W.; Hu, X. One-Pot Synthesis of Cyclic Carbonates from Olefins and CO2 Catalyzed by Silica-Supported Imidazolium Hydrogen Carbonate Ionic Liquids. Microporous Mesoporous Mater. 2023, 356, 112576. [Google Scholar] [CrossRef]
  47. Appaturi, J.N.; Ramalingam, R.J.; Gnanamani, M.K.; Periyasami, G.; Arunachalam, P.; Adnan, R.; Adam, F.; Wasmiah, M.D.; Al-Lohedan, H.A. Review on Carbon Dioxide Utilization for Cycloaddition of Epoxides by Ionic Liquid-Modified Hybrid Catalysts: Effect of Influential Parameters and Mechanisms Insight. Catalysts 2020, 11, 4. [Google Scholar] [CrossRef]
  48. Yue, S.; Qu, H.; Song, X.; Zang, S.; Deng, G. Hydroxy Acid-Functionalized Ionic Liquids as Green Alternatives for the Efficient Catalytic Conversion of Epoxides to Cyclic Carbonates under Solvent and Co-Catalyst-Free Conditions. Catal. Sci. Technol. 2021, 11, 6999–7008. [Google Scholar] [CrossRef]
  49. Li, Z.; Sun, J.; Xu, Q.; Yin, J. Homogeneous and Heterogeneous Ionic Liquid System: Promising “Ideal Catalysts” for the Fixation of CO2 into Cyclic Carbonates. ChemCatChem 2021, 13, 1848–1866. [Google Scholar] [CrossRef]
  50. Comin, E.; Aquino, A.S.; Favero, C.; Mignoni, M.L.; de Souza, R.F.; de Souza, M.O.; Pergher, S.B.C.; da Silva Campos, C.X.; Bernardo-Gusmão, K. Cyclic Carbonate Synthesis via Cycloaddition of CO2 and Epoxides Catalysed by Beta Zeolites Containing Alkyl Imidazolium Ionic Liquids Used as Structure-Directing Agents. Mol. Catal. 2022, 530, 112624. [Google Scholar] [CrossRef]
  51. Qu, Y.; Chen, Y.; Sun, J. Conversion of CO2 with Epoxides to Cyclic Carbonates Catalyzed by Amino Acid Ionic Liquids at Room Temperature. J. CO2 Util. 2022, 56, 101840. [Google Scholar] [CrossRef]
  52. de la Cruz-Martínez, F.; Martínez, J.; Gaona, M.A.; Fernández-Baeza, J.; Sánchez-Barba, L.F.; Rodríguez, A.M.; Castro-Osma, J.A.; Otero, A.; Lara-Sánchez, A. Bifunctional Aluminum Catalysts for the Chemical Fixation of Carbon Dioxide into Cyclic Carbonates. ACS Sustain. Chem. Eng. 2018, 6, 5322–5332. [Google Scholar] [CrossRef]
  53. Mesías-Salazar, Á.; Rojas, R.S.; Carrillo-Hermosilla, F.; Martínez, J.; Antiñolo, A.; Trofymchuk, O.S.; Nachtigall, F.M.; Santos, L.S.; Daniliuc, C.G. Guanidinium Iodide Salts as Single Component Catalysts for CO2 to Epoxide Fixation. New J. Chem. 2024, 48, 105–111. [Google Scholar] [CrossRef]
  54. Neese, F. The ORCA Program System. WIREs Comput. Mol. Sci. 2012, 2, 73–78. [Google Scholar] [CrossRef]
  55. Neese, F. Software Update: The ORCA Program System—Version 5.0. WIREs Comput. Mol. Sci. 2022, 12, e1606. [Google Scholar] [CrossRef]
  56. Becke, A.D. Density-functional Thermochemistry. III. The Role of Exact Exchange. J. Chem. Phys. 1993, 98, 5648–5652. [Google Scholar] [CrossRef]
  57. Weigend, F.; Ahlrichs, R. Balanced Basis Sets of Split Valence, Triple Zeta Valence and Quadruple Zeta Valence Quality for H to Rn: Design and Assessment of Accuracy. Phys. Chem. Chem. Phys. 2005, 7, 3297–3305. [Google Scholar] [CrossRef] [PubMed]
  58. Caldeweyher, E.; Ehlert, S.; Hansen, A.; Neugebauer, H.; Spicher, S.; Bannwarth, C.; Grimme, S. A Generally Applicable Atomic-Charge Dependent London Dispersion Correction. J. Chem. Phys. 2019, 150, 154122. [Google Scholar] [CrossRef]
  59. Ásgeirsson, V.; Birgisson, B.O.; Bjornsson, R.; Becker, U.; Neese, F.; Riplinger, C.; Jónsson, H. Nudged Elastic Band Method for Molecular Reactions Using Energy-Weighted Springs Combined with Eigenvector Following. J. Chem. Theory Comput. 2021, 17, 4929–4945. [Google Scholar] [CrossRef]
  60. Chai, J.-D.; Head-Gordon, M. Long-Range Corrected Hybrid Density Functionals with Damped Atom–Atom Dispersion Corrections. Phys. Chem. Chem. Phys. 2008, 10, 6615–6620. [Google Scholar] [CrossRef]
  61. Chai, J.-D.; Head-Gordon, M. Systematic Optimization of Long-Range Corrected Hybrid Density Functionals. J. Chem. Phys. 2008, 128, 84106. [Google Scholar] [CrossRef]
  62. Riplinger, C.; Sandhoefer, B.; Hansen, A.; Neese, F. Natural Triple Excitations in Local Coupled Cluster Calculations with Pair Natural Orbitals. J. Chem. Phys. 2013, 139, 134101. [Google Scholar] [CrossRef]
  63. Riplinger, C.; Pinski, P.; Becker, U.; Valeev, E.F.; Neese, F. Sparse Maps—A Systematic Infrastructure for Reduced-Scaling Electronic Structure Methods. II. Linear Scaling Domain Based Pair Natural Orbital Coupled Cluster Theory. J. Chem. Phys. 2016, 144, 24109. [Google Scholar] [CrossRef]
  64. Neese, F.; Wennmohs, F.; Hansen, A. Efficient and Accurate Local Approximations to Coupled-Electron Pair Approaches: An Attempt to Revive the Pair Natural Orbital Method. J. Chem. Phys. 2009, 130, 114108. [Google Scholar] [CrossRef] [PubMed]
  65. Adamo, C.; Barone, V. Toward Reliable Density Functional Methods without Adjustable Parameters: The PBE0 Model. J. Chem. Phys. 1999, 110, 6158–6170. [Google Scholar] [CrossRef]
  66. Martínez, J.; de la Cruz-Martínez, F.; Gaona, M.A.; Pinilla-Peñalver, E.; Fernández-Baeza, J.; Rodríguez, A.M.; Castro-Osma, J.A.; Otero, A.; Lara-Sánchez, A. Influence of the Counterion on the Synthesis of Cyclic Carbonates Catalyzed by Bifunctional Aluminum Complexes. Inorg. Chem. 2019, 58, 3396–3408. [Google Scholar] [CrossRef] [PubMed]
  67. Castro-Osma, J.A.; Martínez, J.; de la Cruz-Martínez, F.; Caballero, M.P.; Fernández-Baeza, J.; Rodríguez-López, J.; Otero, A.; Lara-Sánchez, A.; Tejeda, J. Development of Hydroxy-Containing Imidazole Organocatalysts for CO2 Fixation into Cyclic Carbonates. Catal. Sci. Technol. 2018, 8, 1981–1987. [Google Scholar] [CrossRef]
  68. Martínez de Sarasa Buchaca, M.; de la Cruz-Martínez, F.; Francés-Poveda, E.; Fernández-Baeza, J.; Sánchez-Barba, L.F.; Garcés, A.; Castro-Osma, J.A.; Lara-Sánchez, A. Synthesis of Nonisocyanate Poly(Hydroxy)Urethanes from Bis(Cyclic Carbonates) and Polyamines. Polymers 2022, 14, 2719. [Google Scholar] [CrossRef]
  69. Pronoitis, C.; Hakkarainen, M.; Odelius, K. Structurally Diverse and Recyclable Isocyanate-Free Polyurethane Networks from CO2-Derived Cyclic Carbonates. ACS Sustain. Chem. Eng. 2022, 10, 2522–2531. [Google Scholar] [CrossRef]
  70. Schmitt, M.; Strehmel, V. Chemical Reaction of Carbon Dioxide with Bisepoxides for Synthesis of Organic Cyclic Dicarbonates at Ambient Pressure for Polyhydroxy Urethane Synthesis. Org. Process Res. Dev. 2020, 24, 2521–2528. [Google Scholar] [CrossRef]
  71. Grosjean, M.; Berne, D.; Caillol, S.; Ladmiral, V.; Nottelet, B. Dynamic PEG–PLA/Hydroxyurethane Networks Based on Imine Bonds as Reprocessable Elastomeric Biomaterials. Biomacromolecules 2023, 24, 3472–3483. [Google Scholar] [CrossRef]
  72. de la Cruz-Martínez, F.; Martínez de Sarasa Buchaca, M.; Martínez, J.; Fernández-Baeza, J.; Sánchez-Barba, L.F.; Rodríguez-Diéguez, A.; Castro-Osma, J.A.; Lara-Sánchez, A. Synthesis of Bio-Derived Cyclic Carbonates from Renewable Resources. ACS Sustain. Chem. Eng. 2019, 7, 20126–20138. [Google Scholar] [CrossRef]
  73. de la Cruz-Martínez, F.; Francés-Poveda, E.; North, M.; Castro-Osma, J.A.; Lara-Sánchez, A. Base-Catalyzed Highly Regioselective Synthesis of Bio-Based Hydroxyurethanes. Eur. J. Org. Chem. 2024, 27, e202400275. [Google Scholar] [CrossRef]
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Scheme 1. Synthesis of cyclic carbonates starting from CO2 and epoxides.
Scheme 1. Synthesis of cyclic carbonates starting from CO2 and epoxides.
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Figure 1. Organocatalysts evaluated for the synthesis of cyclic carbonates from epoxides and CO2 molecules: (1) 1,3-dimethylimidazolium iodide, (2) triethylammonium bromide, (3) pyridinium bromide, (4) 1-ethyl-2,3-dimethylimidazolium bromide, and (5) (1-butyl) triethylammonium bromide.
Figure 1. Organocatalysts evaluated for the synthesis of cyclic carbonates from epoxides and CO2 molecules: (1) 1,3-dimethylimidazolium iodide, (2) triethylammonium bromide, (3) pyridinium bromide, (4) 1-ethyl-2,3-dimethylimidazolium bromide, and (5) (1-butyl) triethylammonium bromide.
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Figure 2. Cyclic carbonates 7a–i obtained from epoxides 6a–i catalyzed by bifunctional catalyst 1. Selectivity towards the cyclic carbonate was determined by 1H-NMR spectroscopy of the crude reaction mixture and was >99% in all cases. a Conversion determined by 1H-NMR of the reaction mixture; b reaction time 2 h; c isolated yield from purified cyclic carbonate.
Figure 2. Cyclic carbonates 7a–i obtained from epoxides 6a–i catalyzed by bifunctional catalyst 1. Selectivity towards the cyclic carbonate was determined by 1H-NMR spectroscopy of the crude reaction mixture and was >99% in all cases. a Conversion determined by 1H-NMR of the reaction mixture; b reaction time 2 h; c isolated yield from purified cyclic carbonate.
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Figure 3. Cyclic carbonates 9a–e were obtained from their corresponding epoxides 8a–e using catalyst 1. Selectivity towards the cyclic carbonate was determined by 1H-NMR spectroscopy of the crude reaction mixture and was >99% in all cases. a Conversion determined by 1H-NMR of the reaction mixture; b isolated yield from purified cyclic carbonate.
Figure 3. Cyclic carbonates 9a–e were obtained from their corresponding epoxides 8a–e using catalyst 1. Selectivity towards the cyclic carbonate was determined by 1H-NMR spectroscopy of the crude reaction mixture and was >99% in all cases. a Conversion determined by 1H-NMR of the reaction mixture; b isolated yield from purified cyclic carbonate.
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Scheme 2. Synthesis of carvone-derived cyclic carbonate 11 catalyzed by catalyst 1.
Scheme 2. Synthesis of carvone-derived cyclic carbonate 11 catalyzed by catalyst 1.
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Figure 4. (a) 1H-NMR spectrum of catalyst 1 in CDCl3; (b) 1H-NMR spectrum of catalyst 1 + styrene oxide 6a at 80 °C and t = 16 h in CDCl3; (c) 1H-NMR spectrum of catalyst 1 + styrene oxide 6a at 80 °C and CO2 for 30 min in CDCl3; (d) 1H-NMR spectrum of styrene carbonate 7a in CDCl3.
Figure 4. (a) 1H-NMR spectrum of catalyst 1 in CDCl3; (b) 1H-NMR spectrum of catalyst 1 + styrene oxide 6a at 80 °C and t = 16 h in CDCl3; (c) 1H-NMR spectrum of catalyst 1 + styrene oxide 6a at 80 °C and CO2 for 30 min in CDCl3; (d) 1H-NMR spectrum of styrene carbonate 7a in CDCl3.
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Figure 5. Energetic profiles computed on the final MEP for styrene oxide (6a to 7a, left panel) and cyclohexene oxide transformation (8a to 9a, right panel) through NEB-TS procedure at DFT (B3LYP ma-def2-svp D4) level. The whole final path was divided into three different parts to gain higher resolution for both molecular systems.
Figure 5. Energetic profiles computed on the final MEP for styrene oxide (6a to 7a, left panel) and cyclohexene oxide transformation (8a to 9a, right panel) through NEB-TS procedure at DFT (B3LYP ma-def2-svp D4) level. The whole final path was divided into three different parts to gain higher resolution for both molecular systems.
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Figure 6. Reaction mechanism computed for the chemical transformation of styrene oxide (6a) into its respective cyclic carbonate (7a). A set of bond distances (numbers with superscript d) and angles (numbers with superscript a) have been highlighted with different colors for the respective stationary (A–D) and saddle (I–III) points found along the computed MEP. Each stationery and saddle point directly correlates with the points shown in the energetic profile in Figure 5 (left panel). H-bonds established between the oxygen atom from the epoxide moiety and the acidic proton of the catalyst are highlighted in light green. Breaking and making bonds involving oxygen, iodide, and carbon atoms are highlighted in red, violet, and grey colors, respectively. All the distances are expressed in Å and angles in degrees.
Figure 6. Reaction mechanism computed for the chemical transformation of styrene oxide (6a) into its respective cyclic carbonate (7a). A set of bond distances (numbers with superscript d) and angles (numbers with superscript a) have been highlighted with different colors for the respective stationary (A–D) and saddle (I–III) points found along the computed MEP. Each stationery and saddle point directly correlates with the points shown in the energetic profile in Figure 5 (left panel). H-bonds established between the oxygen atom from the epoxide moiety and the acidic proton of the catalyst are highlighted in light green. Breaking and making bonds involving oxygen, iodide, and carbon atoms are highlighted in red, violet, and grey colors, respectively. All the distances are expressed in Å and angles in degrees.
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Figure 7. Reaction mechanism computed for the chemical transformation of cyclohexene oxide (8a) into its respective cyclic carbonate (9a). A set of bond distances (numbers with superscript d) and angles (numbers with superscript a) have been highlighted with different colors for the respective stationary (A–D) and saddle (I–III) points found along the computed MEP. Each stationery and saddle point directly correlates with the points shown in the energetic profile in Figure 5 (right panel). H-bonds established between the oxygen atom from the epoxide moiety and the acidic proton of the catalyst are highlighted in light green. Breaking and making bonds involving oxygen, iodide, and carbon atoms are highlighted in red, violet, and grey colors, respectively. All the distances are expressed in Å and angles in degrees.
Figure 7. Reaction mechanism computed for the chemical transformation of cyclohexene oxide (8a) into its respective cyclic carbonate (9a). A set of bond distances (numbers with superscript d) and angles (numbers with superscript a) have been highlighted with different colors for the respective stationary (A–D) and saddle (I–III) points found along the computed MEP. Each stationery and saddle point directly correlates with the points shown in the energetic profile in Figure 5 (right panel). H-bonds established between the oxygen atom from the epoxide moiety and the acidic proton of the catalyst are highlighted in light green. Breaking and making bonds involving oxygen, iodide, and carbon atoms are highlighted in red, violet, and grey colors, respectively. All the distances are expressed in Å and angles in degrees.
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Scheme 3. Plausible mechanism for the synthesis of cyclic carbonates catalyzed by organocatalyst 1.
Scheme 3. Plausible mechanism for the synthesis of cyclic carbonates catalyzed by organocatalyst 1.
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Table 1. Conversion of styrene oxide 6a into styrene carbonate 7a using organocatalysts 1–5. 1
Table 1. Conversion of styrene oxide 6a into styrene carbonate 7a using organocatalysts 1–5. 1
EntryCatalystConversion 2 (%)TOF 3 (h−1)
1110010
2210010
3310010
4410010
5510010
6110050
722613
83126
948241
10510050
11 4197 (95) 597
12 458383
13 6-00
1 Reactions were carried out at 80 °C and 20 bar CO2 pressure for 2 h using 1–5 mol% of catalysts 1–5 in the absence of solvent. 2 Conversion was determined by 1 H-NMR spectroscopy of the crude reaction mixture. 3 TOF = moles of product/(moles of catalyst·time). 4 Reaction time: 1 h. 5 Isolated yield from purified cyclic carbonate. 6 Reaction carried out in the absence of catalyst.
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Francés-Poveda, E.; Navarro, M.; Beroíza-Duhart, M.; Mahecha, G.L.; Urzúa, J.I.; Valenzuela, M.L.; de la Cruz-Martínez, F.; Douglas-Gallardo, O.A.; Werlinger, F.; Lara-Sánchez, A.; et al. Effective One-Component Organocatalysts for Eco-Friendly Production of Cyclic Carbonates. Reactions 2025, 6, 8. https://doi.org/10.3390/reactions6010008

AMA Style

Francés-Poveda E, Navarro M, Beroíza-Duhart M, Mahecha GL, Urzúa JI, Valenzuela ML, de la Cruz-Martínez F, Douglas-Gallardo OA, Werlinger F, Lara-Sánchez A, et al. Effective One-Component Organocatalysts for Eco-Friendly Production of Cyclic Carbonates. Reactions. 2025; 6(1):8. https://doi.org/10.3390/reactions6010008

Chicago/Turabian Style

Francés-Poveda, Enrique, Marta Navarro, Monserrat Beroíza-Duhart, Genesys L. Mahecha, Julio I. Urzúa, María Luisa Valenzuela, Felipe de la Cruz-Martínez, Oscar A. Douglas-Gallardo, Francisca Werlinger, Agustín Lara-Sánchez, and et al. 2025. "Effective One-Component Organocatalysts for Eco-Friendly Production of Cyclic Carbonates" Reactions 6, no. 1: 8. https://doi.org/10.3390/reactions6010008

APA Style

Francés-Poveda, E., Navarro, M., Beroíza-Duhart, M., Mahecha, G. L., Urzúa, J. I., Valenzuela, M. L., de la Cruz-Martínez, F., Douglas-Gallardo, O. A., Werlinger, F., Lara-Sánchez, A., & Martínez, J. (2025). Effective One-Component Organocatalysts for Eco-Friendly Production of Cyclic Carbonates. Reactions, 6(1), 8. https://doi.org/10.3390/reactions6010008

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