Titanium-Catalyzed Reductive Umpolung Reactions with a Metal-Free Terminal Reducing Agent
作者:Georg Frey、J. Niklas Hausmann、Jan Streuff
DOI:10.1002/chem.201500102
日期:2015.4.7
A new method for titanium-catalyzed reductive umpolung reactions is reported that overcomes the traditional requirement for a stoichiometric metallic reductant. With N,N'-disilylated tetramethyldihydropyrazine as a potent organic reducing agent, reductive carbonyl-nitrile, enone-acrylonitrile and pinacol coupling reactions can be achieved in good yields and stereoselectivities. [Cp2TiI2] is a superior
据报道,一种新的钛催化的还原化学反应的方法克服了对化学计量的金属还原剂的传统要求。用N,N′-二甲硅烷基化的四甲基二氢吡嗪作为有效的有机还原剂,可以良好的收率和立体选择性实现还原性羰基-腈,烯酮-丙烯腈和频哪醇的偶联反应。[Cp2TiI2]是优于[Cp2TiCl2]的催化剂,这可以通过更快地产生活性催化剂[Cp2TiI]来合理化。提出了一种与实验结果相符的机理。