Dipyrromethane–diphosphine: the effect of <i>meso</i> substituents on the formation of nickel complexes and on their performance in the transfer hydrogenation of ketones
作者:Rohit Gupta、Ashok Kumar、Ganesan Mani
DOI:10.1039/d3dt03163b
日期:——
base and a chelated complex of type 2a. In addition, all three ligands react with [NiCl2(DME)] in the presence of a strong base to give a complex of type 3. Furthermore, a novel binuclear Ni(0) complex bearing L1H2 was characterized by X-ray crystallography. Both complexes 2a and 3 (0.5 mol% of loading) catalyze the transfer hydrogenation of a series of aromatic and aliphatic ketones (20 substrates) to
合成了三种在其内消旋位置含有苯基( L1H2 )、乙基( L2H2 )和环己基( L3H2 )基团的二吡咯甲烷-二膦配体及其镍配合物,并进行了结构表征。用 [NiCl 2 (DME)] 处理 Ph 2 C(C 4 H 3 N) 2 -1,9-(CH 2 PPh 2 ) 2 ( L1H2 ) 得到络合物 [NiCl 2 (κ 2 - P , P - L1H2 ) )] 2a 。相反, L2H2和L3H2与 [NiCl 2 (DME)] 的类似反应显示产物混合物含有 [Ni(κ 4 - P , N , N , P - L )] 3型吡咯氮配位络合物,但不含外源碱和2a型螯合复合物。此外,所有三种配体在强碱存在下都与[NiCl 2 (DME)]反应,得到3型配合物。此外,还通过 X 射线晶体学对一种新型双核 Ni(0) 配合物L1H2进行了表征。配合物2a和3 (0.5 mol% 的负载)使用i