An air and moisture tolerant iminotrihydroquinoline-ruthenium(<scp>ii</scp>) catalyst for the transfer hydrogenation of ketones
作者:Jiaoyan Li、Yingmiao Ma、Zheng Wang、Qingbin Liu、Gregory A. Solan、Yanping Ma、Wen-Hua Sun
DOI:10.1039/c8dt01919c
日期:——
with RuCl2(PPh3)3 at room temperature affords the ruthenium(II) chelate (8-NH2-C9H10N)RuCl2(PPh3)2 (E), in which the two triphenylphosphine ligands are disposed mutually cis. By contrast, when the reaction is performed at reflux ligand oxidation/dehydrogenation occurs along with cis–trans reorganization of the triphenylphosphines to form the 8-imino-5,6,7-trihydroquinoline-ruthenium(II) complex, (8
8-氨基-5,6,7,8-四氢喹啉在室温下与RuCl 2(PPh 3)3反应得到钌(II)螯合物(8-NH 2 -C 9 H 10 N)RuCl 2(PPh 3)2(E),其中两个三苯基膦配体相互顺式排列。相反,当反应在回流条件下进行时,配体会发生氧化/脱氢以及三苯基膦的顺式-反式重组,形成8-亚氨基-5,6,7-三氢喹啉-钌(II)络合物,(8-NH C9 H 9 N)RuCl 2(PPh 3) 2( F)。通过单独加热E溶液至回流,也可以高收率获得配合物F。它们的分子结构比较突出了F中的二齿亚胺配体比E中的含胺对应物优越的结合性能。两种络合物在多种烷基-,芳基-和环烷基的酮的转移氢化中非常有效,从而提供其相应的仲醇,其负载量低至0.1 mol%。明显地, F即使在与空气接触的反应釜中,即使是台式质量的2-丙醇也可以提供出色的转化率,而E的催化效率会因空气的存在而降低,但只能在惰性条件下有效地操作。