Mechanistic DFT Study on Rhodium(III)-Catalyzed Double C-H Activation for Oxidative Annulations of 2-Substituted Imidazoles and Alkynes

摘要

A mechanistic understanding of the rhodium(III)catalyzed double C-H activation for oxidative annulations of 2-substituted imidazoles and alkynes was achieved by density functional theory calculations. It is disclosed that the rhodium(III)-acetate-triggered C-H bond cleavage occurs without a directing group, and the C5-H cleavage has the lowest activation barrier among all possible C-H activation processes. The experimental observations in reactions of different imidazole derivatives were explained well by the theoretical results.