Cinchona alkaloid derived squaramide catalyzed diastereo- and enantioselective Michael addition of isocyanoacetates to 2-enoylpyridines
作者:Mei-Xin Zhao、Guang-Yu Zhu、Xiao-Li Zhao、Min Shi
DOI:10.1016/j.tet.2019.01.024
日期:2019.3
An efficient organocatalytic diastereo- and enantioselective Michael addition of α-substituted isocyanoacetates to 2-enoylpyridines catalyzed by cinchona alkaloid-derived squaramide has been achieved, affording the corresponding adducts with two adjacent tertiary-quaternary stereocenters in excellent yields (up to 99%) and good to excellent stereoselectivities (up to >20:1 dr, up to 98% ee) under mild
已成功实现了由金鸡纳生物碱衍生的方酰胺催化的α-取代异氰基乙酸酯到2-烯丙基吡啶的高效有机催化非对映体和对映体选择性迈克尔加成反应,并以优异的收率(高达99%)提供了带有两个相邻的叔-季级立体中心的相应加合物。在温和条件下具有良好的立体选择性(高达> 20:1 dr,高达98%ee)。