Highly enantioselective synthesis of chiral 3-substituted indolines by catalytic asymmetric hydrogenation of indoles

N-Tosyl 3-substituted indoles were hydrogenated with high enantioselectivities (95-98% ee) by use of a trans-chelating chiral bisphosphine, (S,S)-(R,R)-PhTRAP ligand. The chiral catalyst, which was generated in situ from [Rh(nbd)(2)]SbF6, PhTRAP, and Cs2CO3, is useful for enantioselectively synthesizing a range of diverse optically active indolines possessing a chiral carbon at the 3-position.