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Rhodium‐Catalyzed Asymmetric Hydrogenation of Unprotected NH Imines Assisted by a Thiourea |
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| Authors: | Qingyang Zhao Jialin Wen Renchang Tan Kexuan Huang Pedro Metola Prof Rui Wang Prof Eric V Anslyn Prof Xumu Zhang |
| Institution: | 1. Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou 730000 (China);2. Department of Chemistry &Chemical Biology, Department of Medicinal Chemistry, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, NJ 08854 (USA);3. Department of Chemistry, The University of Texas at Austin, 1 University Station A5300, Austin, TX 78712‐0165 (USA) |
| Abstract: | Asymmetric hydrogenation of unprotected NH imines catalyzed by rhodium/bis(phosphine)‐thiourea provided chiral amines with up to 97 % yield and 95 % ee. 1H 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. |
| Keywords: | asymmetric catalysis hydrogenation ion pairs reaction mechanisms rhodium |