报道了炔丙基碳酸酯与异氰酸酯的钯催化的多组分反应(MCR)。值得注意的是,有序插入异氰酸酯可提供两种有价值的N-杂环产物(Z)-6-亚氨基-4,6-二氢-1 H-呋喃[3,4- b ]吡咯-2-胺和(E) -5-亚氨基吡咯烷酮产量高。反应条件的系统分析表明,这些N-杂环产物的选择性可以通过配体和温度控制。
An efficient and convenient palladium-catalyzed cyclization reaction of alkynes with isocyanides is described herein. This protocol allows the practicalsynthesis of many valuable polysubstituted maleimide derivatives after hydrolysis with a broad scope of substrates and mild reaction conditions. C–C, C═O, and C–N bonds were constructed in this transformation with isocyanide serving as both C and N
Intermolecular [2 + 2 + 1] cocyclization of isocyanates, alkynes, and CO (1 atm) proceeded smoothly in the presence of a catalytic amount of Ru3(CO)12 (3.3 mol %) in mesitylene at 130 degrees C for 3 approximately 42 h to give a variety of polysubstituted maleimides in excellent yields with high selectivity. The reaction may involve an azaruthenacyclopentenone intermediate derived from oxidative cyclization of an isocyanate and an alkyne on an active ruthenium species.