Chiral Monodentate Phosphines and Bulky Carboxylic Acids: Cooperative Effects in Palladium-Catalyzed Enantioselective C(sp3)–H Functionalization

Teaming up: The important indoline scaffold is provided with enantiomeric ratios of up to 98:2 in palladium(0)-catalyzed C(sp3)–H activations of aryl triflates. The key is the combination of the electron-rich monodentate Sagephos and the bulky 9H-xanthene-9-carboxylic acid. Both participate in a highly cooperative manner in the enantiodetermining concerted-deprotonation-metalation step (see scheme, Tf=triflate).