Copper-Catalyzed Strain-Driven Enantiospecific C-C Oxidative Addition

While oxidative addition for C-C bond cleavage has been established using noble metals such as palladium and rhodium, analogous transformations with copper have remained elusive. Herein, we report a copper-catalyzed, enantiospecific cross-coupling of gem-difluorocyclopropanes with anilines that furnishes branched fluoroallylamines. Combined experimental and computational studies provide compelling evidence for the oxidative addition of a C-C bond to copper, thereby establishing a new elementary step in copper catalysis. Moreover, our findings reveal an unusual concerted substitution type reductive elimination for C-N bond formation that involves simultaneous C-F and N-H bond cleavage, bypassing conventional allylic metal intermediates and establishing a new mechanistic framework for allylation chemistry. The mechanistic principles demonstrated herein, including the pivotal C-C oxidative addition to copper and the concerted reductive elimination, pave the way for new strategies in catalytic C-C bond functionalization.