Overlooked potential of N,N-bidentate directing-groups in Ni-catalyzed C–H functionalization of benzamides

Abstract

The Ni-catalyzed reactions of benzamides with bicyclic alkenes were explored using DFT calculations. An unprecedented “N–H deprotonation circumvented” catalytic mechanism was proposed, over the more common N–H/C–H activation mechanism, in which (i) the circumvention of N–H deprotonation ensures the presence of N–H⋯O hydrogen bond interaction, thereby stabilizing the critical ortho-C–H functionalization TS; and (ii) the N–H moiety retention results in a weak N⋯Ni σ-coordination, which is flexible to the configurational conversion during the key alkene insertion. These overlooked aspects of the functionalized N,N-bidentate directing groups will aid the design of new related catalytic reactions.