caa a22 4500 605511535 CHVBK 20210128100651.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s00894-015-2733-y doi (NATIONALLICENCE)springer-10.1007/s00894-015-2733-y Theoretical investigation of the mechanism for the cycloaddition of CO2 to epoxides catalyzed by a magnesium(II) porphyrin complex [Elektronische Daten] [Qin Wang, Cai-Hong Guo, Jianfeng Jia, Hai-Shun Wu] The cycloaddition of CO2 to epoxides, catalyzed by Mg(TPP)/TBAI (TPP = tetraphenylporphyrin; TBAI = tetrabutylammonium iodide), was investigated using DFT methods. Epoxides with various substituents were studied to explore steric and electronic effects on the reaction mechanism. Computational results show that the cycloaddition proceeds according to a much easier mechanism in the presence of Mg(TPP) and TBAI than the mechanism that takes place when Mg(TPP) is used as the catalyst. A preference for the epoxide ring-opening to occur at the methine (Cα) or methylene (Cβ) carbon was noted. The ring-closing step leading to the formation of a five-membered carbonate is predicted to determine the reaction rate. For alkyl-substituted epoxides, the β pathway is favorable since steric factors are dominant; for epoxides with a strongly electron-donating group and styrene oxide, the reaction is mainly controlled by electronic factors and proceeds along the α pathway. When the epoxide has a strongly electron-withdrawing group (CF3), both steric and electronic effects play important roles. The calculated reactivity of epoxides with CO2 catalyzed by Mg(TPP)/TBAI is in good agreement with that observed experimentally. Springer-Verlag Berlin Heidelberg, 2015 Porphyrin nationallicence Carbon dioxide nationallicence Epoxide nationallicence Cycloaddition nationallicence DFT nationallicence Wang Qin School of Chemistry and Materials Science, Shanxi Normal University, 041004, Linfen, People's Republic of China aut Guo Cai-Hong School of Chemistry and Materials Science, Shanxi Normal University, 041004, Linfen, People's Republic of China aut Jia Jianfeng School of Chemistry and Materials Science, Shanxi Normal University, 041004, Linfen, People's Republic of China aut Wu Hai-Shun School of Chemistry and Materials Science, Shanxi Normal University, 041004, Linfen, People's Republic of China aut Journal of Molecular Modeling Springer Berlin Heidelberg 21/7(2015-07-01), 1-9 1610-2940 21:7<1 2015 21 894 https://doi.org/10.1007/s00894-015-2733-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00894-015-2733-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wang Qin School of Chemistry and Materials Science, Shanxi Normal University, 041004, Linfen, People's Republic of China aut NATIONALLICENCE 700 1- Guo Cai-Hong School of Chemistry and Materials Science, Shanxi Normal University, 041004, Linfen, People's Republic of China aut NATIONALLICENCE 700 1- Jia Jianfeng School of Chemistry and Materials Science, Shanxi Normal University, 041004, Linfen, People's Republic of China aut NATIONALLICENCE 700 1- Wu Hai-Shun School of Chemistry and Materials Science, Shanxi Normal University, 041004, Linfen, People's Republic of China aut NATIONALLICENCE 773 0- Journal of Molecular Modeling Springer Berlin Heidelberg 21/7(2015-07-01), 1-9 1610-2940 21:7<1 2015 21 894