Porous Carbon Nanosheet‐Supported Chiral Squaramide for Highly Enantioselective Friedel–Crafts Reaction

Abstract

Abstract Porous carbon nanosheets (PCNs) were used for the first time as a support to immobilize a quinine–squaramide catalyst for the asymmetric Friedel–Crafts addition of pyrazolones to isatin ketimines. Relying on its open structure with a macroporous network as well as hydrophobicity, the PCN‐supported catalyst presented catalytic performance comparable to its homogeneous catalyst; the products were obtained in high yields (up to 90 %) with high ee values (up to 99 %). Recycling batch reactions together with a continuous flow process confirmed the stability of the catalyst.