Rhodium‐Catalyzed Asymmetric Reductive Cyclization of Cyclohexadienone‐Tethered (Z)‐α,β‐Unsaturated Amides

Abstract

The hydrobenzofuranone framework is a core structural motif found in natural products. Herein, we report an efficient rhodium‐catalyzed asymmetric reductive cyclization of cyclohexadienone‐tethered (Z)‐α,β‐unsaturated amides and esters, providing hydrobenzofuranones bearing three consecutive stereogenic centers in cis‐cis‐form with good yields, moderate diastereoselectivity, and excellent enantioselectivity. The subgram‐scale experiment and downstream transformations underscore the utility of this protocol. Furthermore, DFT calculations show that the enantioselectivity and diastereoselectivity are determined by the cyclization step.