Asymmetric Synthesis of Silicon‐Stereogenic Silanes by Copper‐Catalyzed Desymmetrizing Protoboration of Vinylsilanes

The catalytic asymmetric creation of silanes with silicon stereocenters is a long‐sought but underdeveloped topic, and only a handful of examples have been reported. Moreover, the construction of chiral silanes containing (more than) two stereocenters is a more arduous task and remains unexploited. We herein report an unprecedented copper‐catalyzed desymmetrizing protoboration of divinyl‐substituted silanes with bis(pinacolato)diboron (B2pin2). This method enables the facile preparation of an array of enantiomerically enriched boronate‐substituted organosilanes bearing contiguous silicon and carbon stereocenters with exclusive regioselectivity and generally excellent diastereo‐ and enantioselectivity. Born to be mild: A mild and efficient desymmetrizing protoboration of bis(vinyl)silanes with B2pin2 or Bpin‐Bdan mediated by a (R,R)‐iPr‐Duphos‐ligated copper catalyst was developed. An array of versatile but challenging enantioenriched borated organosilanes bearing contiguous silicon and carbon stereocenters were obtained with generally excellent diastereo‐ and enantioselectivity.