手性含氮四齿配体催化苯丙酮的不对称氢转移氢化

Asymmetric Transfer Hydrogenation of Propiophenone Catalyzed by Chiral Nitrogen-containing Tetradentate Ligand

利用8-羟基喹啉与手性环己基二胺的反应,合成了对空气和水稳定的手性含氮四齿配体(R,R)-C6N4;进而分别与钌、铑或铱等金属络合物组合,现场生成催化体系,用于苯丙酮的不对称氢转移氢化反应;考察了碱添加量、配体用量和底物与催化剂用量摩尔比对反应性能的影响.结果表明,该配体与RhHCO(PPh3)3的混合体系效果较好,可得到68%ee的对映选择性.

This paper describes a new chiral nitrogen-containing tetradentate ligand （R,R）-C6 N4 synthesized by the interaction of 8-aminoquinoline and chiral cyclohexyl-1,2-diamine in refluxing water. The chiral ligand as a pale-yellow pillar crystals are very stable to air and water. The mixed systems combined from the ligand and various Ru,Rh or Ir complexes have been used as catalyst precursors for asymmetric transfer hydrogenation of propiophenone. The effects of chiral catalytic efficiency on various metal complexes,amount of addition of base and the molar ratios of ligand/metal were also observed. The results indicate that chiral system RhH （CO）（PPh3）3/（R,R）-C6 N4 is a better catalyst for the reduction of propiophenone,leading to the corresponding optically active alcohol up to 68% ee.