Enantioselective Hydrosilylation of Diverse Allenes via Nickel Catalysis

Abstract

ABSTRACT Enantioselective hydrosilylation of allenes remains a significant challenge with a limited scope due to the difficulties in controlling both regioselectivities and enantioselectivities, despite it representing one of the most efficient manners for the preparation of optically pure allylsilanes. Here, we report a general platform for the efficient and modular preparation of diverse allylsilanes via nickel‐catalyzed hydrosilylation of various allene derivatives, including mono‐substituted allenes and 1,3‐disubstituted allenes. Enabled by a newly developed SPSiOL‐derived diphosphinite ligand (SPSiOP), hydrosilylation of mono‐substituted allenes has been realized with excellent regioselectivity and enantioselectivity. Moreover, the first kinetic resolution of racemic 1,3‐disubstituted allenes has been disclosed using a commercially available chiral QuinoxP* ligand, affording a series of secondary allylsilanes with high stereo induction ( S factor up to 133). The resulting enantioenriched allylsilanes are highly synthetically useful, which has been demonstrated by a variety of transformations of the silyl and alkene functional groups, culminating in efficient synthesis of silacycles and formal synthesis of several bioactive molecules.