Secondary amines as coupling partners in direct catalytic asymmetric reductive amination

• Published in: Chemical science (Cambridge) Vol. 10; no. 16; pp. 4509 - 4514
• Main Authors: Wu, Zitong, Du, Shaozhi, Gao, Guorui, Yang, Wenkun, Yang, Xiongyu, Huang, Haizhou, Chang, Mingxin
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 28.04.2019
• Subjects: Amines; Asymmetry; Catalysis
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c9sc00323a

The secondary amine participating asymmetric reductive amination remains an unsolved problem in organic synthesis. Here we show for the first time that secondary amines are capable of effectively serving as N-sources in direct asymmetric reductive amination to afford corresponding tertiary chiral amines with the help of a selected additive set under mild conditions (0-25 °C). The applied chiral phosphoramidite ligands are readily prepared from BINOL and easily modified. Compared with common tertiary chiral amine synthetic methods, this procedure is much more concise and scalable, as exemplified by the facile synthesis of rivastigmine and -methyl-1-phenylethanamine.