*3.1. Materials*

The reagents were obtained from Acros and Sigma-Aldrich. Hexane and dichloromethane were dried over P2O5. 1,4-Dioxane, diethyl ether, tetrahydrofuran, toluene, benzene, and anisole were dried over sodium. Dried 1,2-dimethoxyethane was obtained from Sigma-Aldrich. 1-Alkynyl derivatives of phosphine oxides and 1-alkynyl phosphine sulfides **1** were prepared by the oxidation of 1-alkynyl phosphines with 30% aq. H2O2 [27] and based on the reaction of 1-alkynyl phosphines with sulfur [28], respectively. 1-Alkynylamines **7a**, **7b**, and **7d** were synthesized by aminomethylation of terminal alkynes by bisamine [29]. Alkynylamines **7c** and **7e** were prepared by aminomethylation of terminal alkynes with aqueous formaldehyde, 37 wt. % in H2O and secondary amines using a CuI catalysis [30]. Nuclear magnetic resonance spectroscopy was performed. NMR spectra were recorded on a Brucker Avance 400 spectrometer at 400 MHz for 1H and at 100 MHz for 13C in CDCl3. The numbering of atoms in the 1H and 13C NMR spectra of the compounds **3a**–**c**, **4a**, **5**, **6**, **8a**, **9a**–**d**, **10d**, **10e**, **12a**, **13b**,**c**, **14c**, **16**, **17** is shown in the Supplementary Materials. X-ray diffraction analysis was performed with an XCaliburEos diffractometer (graphite monochromator, MoKα radiation, λ = 0.71073 Å, w-scan mode, 2θmax = 62◦). The data were treated using the CrysAlisProOxfordDiffractionLtd. program package, version 1.171.36.20. The refinement was done with the SHELX97 program package [31]. Elemental analysis was implemented with a Carlo-Erba CHN 1106 elemental analyzer. Mass spectra were obtained using a Finnigan 4021 instrument. The yields of chemical reaction products were obtained from the isolated amount of 2-alkenyl amines, 1-alkenyl phosphine oxides, and 1-alkenyl phosphine sulfides obtained from starting alkynes. All quantumchemical calculations were carried out using the B3LYP/6-31G(d,p) basis set (Gaussian 09 software) [32]. The 13C NMR and 1H NMR data of the products are shown in the Supplementary Materials.
