A Versatile Enantioselective Catalytic Cyclopropanation‐Rearrangement Approach to the Divergent Construction of Chiral Spiroaminals and Fused Bicyclic Acetals

A highly enantioselective synthesis of various chiral heterobicyclic molecules including spiroaminals and fused bicyclic acetals has been developed via a chiral copper catalyzed cyclopropanation‐rearrangement (CP‐RA) approach under mild reaction conditions. Remarkably, the asymmetric CP‐RA for exocyclic vinyl substrates without a pro‐stereogenic carbon at the β‐position has been realized for the first time and a broad substrate scope with excellent results (33 examples; 34–99 % yields; >95/5 dr and 91–99 % ee ) has been achieved. An application of a successive enantioselective CP‐RA approach was also described, providing a concise access to complex chiral heteropolycycles.