Cu(I)-based chiral catalysts bearing binaphthyl-Proline hybrid ligands and their application in enantioselective Friedel-Crafts reactions of indoles with isatins

Abstract

Highly enantioselective Friedel-Crafts reactions of indoles with isatins were realized using chiral Cu(I) catalyst bearing BINOL and proline-based electronically and sterically tunable chiral O–N–N tridentate ligands. Such catalyst system showed excellent performance in enantioselective Friedel-Crafts alkylation of different indoles, and a series of 3-indolyl-3-hydroxyoxindoles were obtained in high yields (90–98 %) and excellent enantioselectivities (82–98 % ee) under mild reaction conditions.