CuH-Catalyzed Asymmetric Intramolecular Reductive Coupling of Allenes to Enones.

The CuH-catalyzed asymmetric intramolecular reductive coupling of allenes to enones is successfully realized, providing cis-hydrobenzofurans with promising yields and excellent enantioselectivities. Such brilliant enantioselectivities are partially contributed by CuH-catalyzed favorable kinetic resolution of the cyclization products. This protocol tolerates a broad range of functional groups, allowing for further construction of tricyclic and bridged-ring structures. Moreover, the meta-chiral functionalization of 4-substituted phenol and asymmetric dearomatization modification of phenol-contained bioactive molecules are also described.