Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada.
Chem Commun (Camb). 2010 Jun 21;46(23):4109-11. doi: 10.1039/c002759f. Epub 2010 Mar 19.
An additives study for the alkyl-alkyl Negishi reaction using an NHC-Pd catalyst revealed that bromide salts promote coupling while the cation is mechanistically benign. A double titration revealed that the cross-coupling begins at a 1 : 1 ratio of LiBr : (n)BuZnBr, suggesting that a higher-order zincate, presumably Li(m)Zn((n)Bu)Br(3)((2-m)-), is the active transmetalating agent.
采用 NHC-Pd 催化剂对烷基-烷基 Negishi 反应进行添加剂研究表明，溴化物盐促进偶联，而阳离子在机理上是良性的。双滴定表明，交叉偶联开始于 LiBr：(n)BuZnBr 的 1:1 比例，表明更高阶的锌酸盐，可能是 Li(m)Zn((n)Bu)Br(3)((2-m)-)，是活性的 transmetalating 试剂。
