Asymmetric Transfer Hydrogenations of 2,3-Disubstituted Quinoxalines with Ammonia Borane
作者:Songlei Li、Wei Meng、Haifeng Du
DOI:10.1021/acs.orglett.7b00935
日期:2017.5.19
An asymmetrictransferhydrogenation of 2,3-disubstituted quinoxalines using a chiral frustrated Lewis pair of Piers’ borane and (R)-tert-butylsulfinamide as the catalyst with ammoniaborane 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,