A Highly<i>cis</i>-Selective and Enantioselective Metal-Free Hydrogenation of 2,3-Disubstituted Quinoxalines
作者:Zhenhua Zhang、Haifeng Du
DOI:10.1002/anie.201409471
日期:2014.11.13
A wide range of 2,3‐disubstituted quinoxalines have been successfully hydrogenated with H2 using borane catalysts to produce the desired tetrahydroquinoxalines in 80–99 % yields with excellent cis selectivity. Significantly, the asymmetric reaction employing chiral borane catalysts generated by the in situ hydroboration of chiral dienes with HB(C6F5)2 under mild reaction conditions has also been achieved
使用硼烷催化剂已成功地将多种2,3-二取代的喹喔啉用H 2氢化,以80-99%的产率产生所需的四氢喹喔啉,并具有出色的顺式 选择性。值得注意的是,在温和的反应条件下,采用手性二硼烷与HB(C 6 F 5)2进行手性二烯氢硼化生成的手性硼烷催化剂的不对称反应也达到了96%ee,这是第一个催化不对称体系。提供光学活性的顺式-2,3-二取代的1,2,3,4-四氢喹喔啉。