Organomagnesium-Catalyzed Isomerization of Terminal Alkynes to Allenes and Internal Alkynes
作者:Raphaël Rochat、Koji Yamamoto、Michael J. Lopez、Haruki Nagae、Hayato Tsurugi、Kazushi Mashima
DOI:10.1002/chem.201500179
日期:2015.5.26
the transformation of these terminal alkynes into allenes and further to internal alkynes under mild conditions. To the best of our knowledge, this example is the first of an organomagnesium‐catalyzed isomerization of alkynes. Notably, the reactions proceeded through temporally separated autotandem catalysis, thus allowing the isolation of the allene or internal alkyne species in good yields. Mechanistic
通过N,N-二烷基胺亚胺配体1和二苄基镁的亚胺部分的苄基化反应合成有机镁络合物2。3-芳基-1-丙炔与2反应形成相应的四炔基络合物,在温和条件下,这些络合物可作为催化剂将这些末端炔烃转化为丙二烯,并进一步转化为内部炔烃。据我们所知,该实例是炔烃有机镁催化异构化的第一个实例。值得注意的是,反应通过暂时分离的自动串联催化进行,从而允许以高收率分离出烯丙基或内部炔烃。机理实验表明,具有催化活性的四炔基络合物由炔基镁,烯丙基镁和炔丙基镁物种的互变异构混合物组成。