Copper‐Catalyzed Asymmetric Radical 1,2‐Alkylesterification of 1,3‐Dienes with Cycloalkyl Hydroperoxides and Acids

Abstract Transition‐metal‐catalyzed radical relay cross‐coupling reactions of 1,3‐dienes have recently emerged as one of the most powerful methods for construction of structurally diverse allylic compound in a single chemical step. However, there still has been limited success in expanding substrate scope of radical precursors and coupling partners, as well as exploring catalytic asymmetric variants. Herein, we report a copper‐catalyzed enantioselective three‐component 1,2‐alkylesterification of 1,3‐dienes using cycloalkyl hydroperoxides as the carbonyl‐containing alkyl radical sources and carboxylic acids as O‐nucleophiles under mild and redox‐neutral conditions. This protocol features broad substrate scope and good functional group tolerance with respect to each component, providing practical access to a variety of distally keto‐functionalized allylic esters with high enantioselectivity. Mechanistic studies suggest the involvement of a sequential radical relay and C−O cross‐coupling in this three‐component radical reaction.