Cyclic-Protected Hexafluoroacetone as an Air-Stable Liquid Reagent for Trifluoromethylations
作者:Kazuyuki Negishi、Kohsuke Aikawa、Koichi Mikami
DOI:10.1002/ejoc.201600711
日期:2016.8
reagent is readily synthesized from gaseous hexafluoroacetone and 2-methylproline on a gram scale. The reaction of the trifluoromethylating reagent with tert-butoxy cuprate K[Cu(OtBu)2] leads to the CuCF3 in high yield. This species is directly formed from the tetrahedral cuprate intermediate through intramolecular migration of the trifluoromethyl group to copper. The CuCF3 reagent prepared in situ by
空气稳定的液态三氟甲基化试剂很容易从气态六氟丙酮和 2-甲基脯氨酸以克规模合成。三氟甲基化试剂与叔丁氧基铜酸盐 K[Cu(OtBu)2] 反应以高产率生成 CuCF3。该物质是通过三氟甲基基团向铜的分子内迁移由四面体铜酸盐中间体直接形成的。通过我们的方法原位制备的 CuCF3 试剂可用于芳基碘化物、芳基硼酸和末端炔烃的三氟甲基化反应,产率甚至达到克级。此外,CuC2F5 试剂可以用同样的方法制备,这可以用于芳基硼酸或芳基溴化物的五氟乙基化反应,收率很好。