A comprehensive study of the effects of spectator ligands, transition metals and lithium halide additives on the efficiency of iron, nickel and palladium-catalyzed cross-coupling reactions of cyclohexyl magnesium bromide with fluorinated bromobenzenes
作者:Adnan Dahadha、Wolfgang Imhof
DOI:10.3998/ark.5550190.p008.044
日期:——
(CH2)n, n = 1, 2, 3) have been used as the precatalysts. Palladium based catalysts give high yields of the coupling product with the Grignard reagent itself whereas lithium halides are needed as additives to achieve comparable efficiencies if nickel and iron catalysts are used. Yields also depend on the chain length of the bridging units and on the fact whether fluorine substituents are present in
十三种单、双和三氟化溴苯衍生物已与环己基溴化镁或相应的氯化锂或溴化锂加合物偶联。具有通式 [MCl2(dppx)] (x = (CH2)n, n = 1, 2, 3) 的铁、镍和钯配合物已被用作预催化剂。钯基催化剂与格氏试剂本身产生高产率的偶联产物,而如果使用镍和铁催化剂,则需要卤化锂作为添加剂以实现可比的效率。产率还取决于桥接单元的链长以及氟取代基是否存在于溴的邻位这一事实。