Stereoselective synthesis and applications of nitrogen substituted donor–acceptor cyclopropanes (N-DACs) in the divergent synthesis of azacycles
作者:Santosh J. Gharpure、U. Vijayasree、S. Raja Bhushan Reddy
DOI:10.1039/c2ob06591f
日期:——
A new, highly stereoselective intramolecular cyclopropanation of vinylogous carbamates with carbenes in the presence of Cu(acac)2 as the catalyst has been developed for the construction of cyclopropapyrrolidinones. The âsynâ isomer of N-DAC can be converted to the âantiâ isomer by simple silica gel treatment. Regioselective cleavage of each of the cyclopropane bonds of these two acceptor substituted N-DACs led to a diverse array of azacycles.
开发了一种新型的高立体选择性分子内烯丙基氨基甲酸酯与卡宾的环丙烷化反应,以Cu(acac)2为催化剂,用于构建环丙烷吡咯烷酮。通过简单的硅胶处理,可将N-DAC的顺式异构体转化为反式异构体。这两种受体取代的N-DAC的环丙烷键的区域选择性断裂,产生了一系列多样性的氮杂环化合物。