DFT study on the rhodium-catalyzed oxidative C-H allylation of benzamides with 1,3-dienes by ally-to-ally 1,4-Rh(III) migration

摘要

The reaction mechanisms of Rh-catalyzed C-H allylation of benzamide with 1,3-diene were investigated by employing the density functional theory (DFT) calculations. Five main steps are included in this reaction: N-H bond activation, C-H bond activation, olefin insertion, 1,4-Rh migration, and beta-hydride elimination. The rate-determining step is beta-hydride elimination according to our calculations. Lam et al. have proposed three possible mechanisms for the 1,4-Rh migration, but the barriers are calculated to be high. In contrast, the H-migration process from methyl group to N center and to C4 center successively is the most feasible one, consistent with the deuterium transfer experiment. (C) 2019 Elsevier B.V. All rights reserved.