A Convenient Method for the Synthesis of Protic 2-(Tertiary phosphino)-1-amines and Their Cp*RuCl Complexes

A variety of protic 2-(tertiary phosphino)-1-amines (R2PCH2CHR′NHR′′, P−NH) have been prepared from 2-oxazolidinones and secondary phosphines using a newly developed acid-promoted decarboxylative C−P bond formation reaction. Treatment of the resulting chiral P−NH compounds with Cp*RuCl(isoprene) in CH2Cl2 smoothly furnished chiral Cp*RuCl(P−NH) complexes with a typical three-legged piano-stool structure, which prove to be excellent catalyst precursors for asymmetric reactions, including the isomerization of allylic alcohols and hydrogenation of imides.本研究通过全新开发的酸促进脱羧C−P键形成反应，以2-恶唑烷酮类化合物与二级膦为原料，合成了一系列质子型2-(叔膦基)-1-胺类（protic 2-(tertiary phosphino)-1-amines，P−NH）化合物。将所得手性P−NH化合物与Cp*RuCl(异戊二烯)在二氯甲烷（CH₂Cl₂）中反应，可顺利得到具有典型三脚钢琴凳式结构的手性Cp*RuCl(P−NH)配合物。该类配合物是性能优异的不对称反应催化剂前驱体，可用于烯丙醇异构化、酰亚胺氢化等多种不对称催化过程。