**3. Materials and Methods**

Reactions were monitored by analytical thin-layer chromatography (TLC) using silica gel 60 F254 pre-coated glass plates (0.25 mm thickness) and visualized using UV light. Flash chromatography was carried out on silica gel (230–400 mesh). Proton NMR spectra were recorded on spectrometers operating at 300 MHz (Bruker Fourier 300); proton chemical shifts are reported in ppm (δ) with the solvent reference relative to tetramethylsilane (TMS) employed as the internal standard (CDCl3: δ = 7.26 ppm). 13C-NMR spectra were recorded on 300 MHz spectrometers (Bruker Fourier 300) operating at 75 MHz, with complete proton decoupling; carbon chemical shifts are reported in ppm (δ) relative to TMS with the respective solvent resonance as the internal standard (CDCl3: δ = 77.0 ppm). Mass spectra and accurate mass analysis were carried out on a VG AUTOSPEC- M246 spectrometer (double-focusing magnetic sector instrument with EBE geometry) equipped with EI source or with LCQ Fleet ion trap mass spectrometer, ESI source, with acquisition in positive ionization mode in the mass range of 50–2000 m/z. Dry solvents were purchased and stored under nitrogen over molecular sieves (bottles with crown caps). All chemicals were purchased from commercial suppliers and used without further purification unless otherwise specified.

#### *3.1. General Procedure for the Synthesis of Tetrasubstituted Nitroalkenes (***3***)*

Tetrasubstituted nitroalkenes (**3**) were synthetized using a two-step procedure: Firstly the formation of an acrylate intermediate (**2**) by a Horner–Wasdforth–Emmons reaction of an appropriate ketone (**1**) with trimethylphosphonoacetate and sodium hydride, following by a nitration reaction of this intermediate with a mixture of CAN-NaNO2 as an effective nitration reagent.

Compounds **2a**–**f** were synthetized using conditions reported in the literature [9]. First, a solution of trimethyl phosphonoacetate (5.21 mmol) in 20 mL of THF was cooled to 0 ◦C. Then, sodium hydride (5.21 mmol) was added portion-wise and the mixture was stirred for 30 min. After this time, the appropriate ketone (4.17 mmol) was added at the same temperature and the reaction mixture was allowed to warm to room temperature and stirred for 24 h at the right temperature. Then, 20 mL of saturated solution of ammonium chloride was added dropwise and the mixture was extracted with Et2O.

The combined organic phases were dried using MgSO4, filtered and concentrated in vacuo. The solvent was eliminated under reduced pressure and the crude product was purified using column chromatography and hexanes/EtOAc as eluent. The 1H-NMR of compounds **2a**–**f** were in agreement with the published ones. Compounds **2a**–**f** were directly used in the next step after purification.

Acrylates **2a, 2b, 2c, 2d, 2e** and **2f** (5.68 mmol) were dissolved in 50 mL of acetonitrile and cooled to 0 ◦C. Then, sodium nitrite (17 mmol) and cerium ammonium nitrate (17 mmol) were added at the same temperature, and the reaction mixture was allowed to warm to room temperature and stirred for 24 h. After this time, the reaction was filtered through a pad of celite, and the filtrate was concentrated under reduced pressure. The residue was poured into cold water and extracted with DCM (3 × 50 mL). The combined organic layers were dried using MgSO4, filtered and concentrated in vacuo. The crude product was purified by column chromatography using an appropriate mixture of solvents to afford nitroacrylates. For further details see the Supporting Information.
