An unprecedented reductive [2 + 1] annulation of α-keto esters with alkynones mediated by P(NMe2)3 is described. Although this nonmetal cyclopropenation is a nucleophilic process, attributed to the ester migration via a formal [2 + 2] cycloaddition reaction of Kukhtin–Ramirez adducts and alkynones followed by a fragmentation, cyclopropenes with an unbiased alkene scaffold are formed in good to excellent
描述了一种空前的还原性[2 +1],由P(NMe 2)3介导的α-
酮酯与
炔烃的还原性环化反应。尽管这种非
金属
环丙烷化是一个亲核过程,这归因于酯的迁移是通过Kukhtin-Ramirez加合物和
炔烃的正式[2 + 2]环加成反应,然后发生断裂,但形成了具有无偏烯烃骨架的环
丙烯,收率良好,因此提供了与亲电子
金属催化的
环丙烷化的有希望的互补性。