On the question of free radical intermediacy in cycloaddition reactions of diazocarbonyl compounds to olefins under copper(II) chelate catalysis
作者:Miguel E. Alonso、Maria I. Hernández、Matilde Gómez、Patricia Jano、Sarah Pekerar
DOI:10.1016/s0040-4020(01)96629-3
日期:1985.1
catalyzed thermal cycloaddition of ethyl diazoacetate, dimethyl diazomalonate, ethyl-2-diazo-3-oxobutyrate, and ethyl diazopyruvate, representatives of diazocarbonyl additions that yield cyclopropanes and dihydrofurans, respectively, to olefins, has been examined in terms of the possible participation of radical species in intermediary stages. To this purpose, the title diazocarbonyl compounds were exposed
分别研究了重氮铜,重氮丙二酸二甲酯,重氮丙二酸二甲酯,-2-重氮-3-氧丁酸乙酯和重氮丙酮酸乙酯的螯合铜催化的热环加成反应,这些重氮分别代表重氮羰基加成反应生成环丙烷和二氢呋喃。自由基物种可能在中间阶段的参与。为此,将标题重氮羰基化合物在催化条件下暴露于1-甲基-1-环丙基乙烯和1,1-二环丙基乙烯。在环丙烷化反应以及提供杂环的反应中,不存在环丙基羰基至丁烯基重排产物的现象表明,具有自由基性质的中间体可能不参与环加成过程。反过来,