Supported Bifunctional Chiral Thioureas as Catalysts in the Synthesis of 3-Amino-2-Oxindoles through Enantioselective aza-Friedel-Crafts Reaction: Application in Continuous Flow Processes

Supported cinchone-derived thioureas promote highly enantioselective aza-Friedel-Crafts reaction of different naphthols with a variety of N-Boc ketimines derived from isatin. The catalysts are recoverable and reusable, and one of the supported catalysts has been used in a flow process allowing the synthesis of 3-amino-2-oxindole derivatives in multigram scale with high yield and enantioselectivity.