Laboratorio de Catálisis Homogénea, Departamento de Química y Ciencia de los Materiales, Unidad Asociada al CSIC, Centro de Investigación en Química Sostenible (CIQSO), Campus de El Carmen s/n, Universidad de Huelva, 21007-Huelva, Spain.
Chemistry. 2011 Dec 23;17(52):14885-95. doi: 10.1002/chem.201102900. Epub 2011 Dec 2.
The Pd(0) complexes [(NHC)PdL(n)] (NHC=N-heterocyclic carbene ligand; L=styrene for n=2 or PR(3) for n=1) efficiently catalyse olefin cyclopropanation by using ethyl diazoacetate (EDA) as the carbene source with activities that improve on previously described catalytic systems based on this metal. Mechanistic studies have shown that all of these catalyst precursors deliver the same catalytic species in solution, that is, [(IPr)Pd(sty)], a 14e(-) unsaturated intermediate that further reacts with EDA to afford [(IPr)Pd(=CHCO(2)Et)(sty)], from which the cyclopropane is formed.
Pd(0) 配合物 [(NHC)PdL(n)](NHC=N-杂环卡宾配体;L=苯乙烯,n=2;或 PR(3),n=1)有效地催化烯烃环丙烷化,使用乙基重氮乙酸酯(EDA)作为卡宾源,其活性优于先前基于该金属的描述催化体系。机理研究表明,所有这些催化剂前体在溶液中都提供相同的催化物种,即 [(IPr)Pd(sty)],一种 14e(-)不饱和中间体,它与 EDA 进一步反应得到 [(IPr)Pd(=CHCO(2)Et)(sty)],环丙烷由此形成。