Remote Enantioselective Redox ε‐Alkylation of Copper Allylic Allenylidenes with Enals

Abstract The development of asymmetric functionalization at positions distant from the catalytic center—achieving high complexity, diversity, and stereocontrol—poses significant challenges. Here, we introduce an N ‐heterocyclic carbene (NHC)/copper cooperative catalytic strategy for the regioselective remote ε‐alkylation of yne‐allylic esters and yne‐heteroarenic esters with enals, producing a diverse array of oxindoles with outstanding stereoselectivity (up to >95:5 dr, 99% ee). Remarkably, copper allylic allenylidenes are proven to be compatible with NHC‐bound intermediates, facilitating efficient, regioselective, and stereoselective intermolecular C─C bond formation at distant sites.