Scope and Mechanistic Analysis for Chemoselective Hydrogenolysis of Carbonyl Compounds Catalyzed by a Cationic Ruthenium Hydride Complex with a Tunable Phenol Ligand
作者:Nishantha Kalutharage、Chae S. Yi
DOI:10.1021/jacs.5b06097
日期:2015.9.2
A cationic ruthenium hydride complex, [(C6H6)(PCy3)(CO)RuH](+)BF4(-) (1), with a phenol ligand was found to exhibit high catalytic activity for the hydrogenolysis of carbonyl compounds to yield the corresponding aliphatic products. The catalytic method showed exceptionally high chemoselectivity toward the carbonyl reduction over alkene hydrogenation. Kinetic and spectroscopic studies revealed a strong
发现带有苯酚配体的阳离子氢化钌络合物 [(C6H6)(PCy3)(CO)RuH](+)BF4(-) (1) 对羰基化合物的氢解具有很高的催化活性,得到相应的脂肪族产品。该催化方法对羰基还原比烯烃氢化表现出极高的化学选择性。动力学和光谱研究揭示了苯酚配体对催化剂活性的强烈电子影响。4-甲氧基苯乙酮氢解的哈米特图显示了催化系统 1/pX-C6H4OH 的两个相反的线性斜率(对于 X = OMe、t-Bu、Et 和 Me,ρ = -3.3;对于 X = F、Cl 和 CF3)。对于由具有电子释放基团 (kH/kD = 1.7-2.5; X = OMe, Et) 的 1/pX-C6H4OH 催化的氢解反应,观察到正常的氘同位素效应,而对具有吸电子基团 (kH/kD = 0.6-0.7; X = Cl, CF3) 的 1/pX-C6H4OH 测量逆同位素效应。经验速率定律由 4-甲氧基苯乙酮的氢解确定:对于由