A Catalytic Asymmetric Borono Variant of Hosoml-Sakural Reactions with N,O-Aminals

摘要

Catalytic intermolecular cross-couplings between C_(sp~3) centers, such as O,O-acetals and N,O-aminals, and allyl species are challenging, but provide convenient access to various important substance classes such as homoallyl ethers and amines. For these transformations, Hosomi-Sakurai reactions using allyl silicon-based reagents are generally employed. These carbon-carbon bond formations proceed through either Lewis acid or Br0nsted acid activation of the electrophile to generate a stabilized carbenium ion intermediate that can react with a silicon-based nucleophile. However, catalytic asymmetric Hosomi-Sakurai allylations of C_(sp~3) centers have proved to be challenging.