title: Rhodium-catalyzed asymmetric hydrogenation of unprotected NH imines assisted by a thiourea.
abstract: Asymmetric hydrogenation of unprotected NH imines catalyzed by rhodium/bis(phosphine)-thiourea provided chiral amines with up to 97% yield and 95% ee. (1)H NMR studies, coupled with control experiments, implied that catalytic chloride-bound intermediates were involved in the mechanism through a dual hydrogen-bonding interaction. Deuteration experiments proved that the hydrogenation proceeded through a pathway consistent with an imine.
authors.affiliation: Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry &Chemical Biology, Department of Medicinal Chemistry, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, NJ 08854 (USA).
authors.forename: Qingyang
authors.initials: Q
authors.lastname: Zhao
authors.forename: Jialin
authors.initials: J
authors.lastname: Wen
authors.forename: Renchang
authors.initials: R
authors.lastname: Tan
authors.forename: Kexuan
authors.initials: K
authors.lastname: Huang
authors.forename: Pedro
authors.initials: P
authors.lastname: Metola
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Eric V
authors.initials: EV
authors.lastname: Anslyn
authors.forename: Xumu
authors.initials: X
authors.lastname: Zhang
mesh_terms: D002384:Catalysis; D006865:Hydrogenation; D007097:Imines / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism; D013890:Thiourea / Q000737:chemistry*
chemical_list: D007097:Imines; D012238:Rhodium; D013890:Thiourea
keywords: asymmetric catalysis; hydrogenation; ion pairs; reaction mechanisms; rhodium