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

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.