Zhusheng Yang, Fei Chen,* Yanmei He, Nianfa Yang, and Qing-Hua Fan*

A highly enantioselective synthesis of indolines by asymmetric hydrogenation of 1H-indoles and 3H-indoles at ambient temperature and pressure, catalyzed by chiral phosphine-free cationic ruthenium complexes, has been developed. Excellent enantio- and diastereoselectivities (up to > 99% ee, > 20:1 d.r.) were obtained for a wide range of indole derivatives, including unprotected 2-substituted and 2,3-disubstituted 1H-indoles, as well as 2-alkyl- and 2-aryl-substituted 3H-indoles.

This work has been published in Angew. Chem. Int. Ed. 2016, 55, 13863-13866.