Catalytic asymmetric michael addition/cyclization of isothiocyanato oxindoles: Highly efficient and versatile approach for the synthesis of 3,2′-pyrrolidinyl mono- and bi-spirooxindole frameworks

摘要

A-spiro-ing to greatness: The catalytic asymmetric Michael addition/cyclization of isothiocyanato oxindoles has been realized. This versatile approach provides an easy and highly efficient way to access not only the enantioselective synthesis of 3,2′-pyrrolidinyl spirooxindole frameworks, but also the construction of enatiomerically enriched bi-spirooxindoles containing three contiguous stereocenters and two spiro-quaternary centers (see scheme).