Enantioselective synthesis of 2-methyl indolines by palladium catalysed asymmetric C(sp3)–H activation/cyclisation

Abstract

The first example of the enantioselective methyl C–H activation by an intramolecular ArPdX species and subsequent cyclisation was developed. Palladium catalysts using commercially available chiral diphosphines yield good ee's (up to 93% ee) in the synthesis of 2-methyl indolines from 2-halo N-isopropyl anilides. This approach was also employed for the synthesis of enantioenriched cyclohexyl fused indolines with moderate enantioselectivities.