Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
University of Chinese Academy of Sciences , Beijing 100049, China.
Org Lett. 2017 May 19;19(10):2604-2606. doi: 10.1021/acs.orglett.7b00935. Epub 2017 May 1.
An asymmetric transfer hydrogenation of 2,3-disubstituted quinoxalines using a chiral frustrated Lewis pair of Piers' borane and (R)-tert-butylsulfinamide as the catalyst with ammonia borane as the hydrogen source has been successfully realized. For 2-alkyl-3-arylquinoxaline substrates, cis-tetrahydroquinoxalines were obtained as the predominant products in high yields with 77-86% ee. In contrast, trans isomers were often furnished as major products for the reactions of 2,3-dialkylquinoxalines with up to >99% ee.
已成功实现了使用 Piers 硼烷和（R）-叔丁基亚磺酰胺组成的手性受阻路易斯对作为催化剂，以氨硼烷作为氢源，对 2,3-二取代喹喔啉进行不对称转移氢化。对于 2-烷基-3-芳基喹喔啉底物，顺式四氢喹喔啉作为主要产物，以 77-86%ee 值获得高产率。相比之下，对于 2,3-二烷基喹喔啉的反应，通常以主要产物形式得到反式异构体，ee 值高达>99%。
