N‐Heterocyclic Carbene‐Catalyzed Enantioselective Synthesis of Spirocyclohexane Oxindoles

A variety of structurally diverse spirocyclohexane oxindoles featuring a quaternary carbon centre have been successfully constructed through an N‐heterocyclic carbene‐catalyzed [4+2] annulation of isatin‐derived enals with α cyano‐β‐methylenones. This domino process exhibits a wide substrate tolerance, operates under mild conditions, and yields products with high enantioselectivity.