Isothiourea-catalysed transfer hydrogenation of α,β-unsaturated para-nitrophenyl esters
作者:Jiufeng Wu、Claire M. Young、Andrew D. Smith
DOI:10.1016/j.tet.2020.131758
日期:2021.1
transfer hydrogenation of α,β-unsaturated para-nitrophenyl esters using Hantzsch ester has been developed. Good to excellent yields are observed using α,β-unsaturated aryl esters bearing electron-withdrawing β-substituents. The aryl ester products can either be isolated directly in moderate to excellent yields (7 examples, 16–98%) or converted to the corresponding methyl esters (2 examples, 68–70% yield)
已开发出使用Hantzsch酯的异硫脲催化的α,β-不饱和对硝基苯酯转移氢化的方案。使用带有吸电子β-取代基的α,β-不饱和芳基酯,观察到良好至优异的产率。可以直接分离出芳基酯产物,以中等至优异的收率(7例,产率为16–98%)或转化为相应的甲酯(2例,产率为68–70%)或苄基酰胺(2例,44-88)。氢化酯与适当的亲核试剂进行原位反应后得到 初步实验表明,当使用手性异硫脲催化剂时,适度的对映体诱导(76:24 er)是可能的。