离子液体在苯乙酮不对称加氢反应中的应用

摘要

Asymmetric hydrogenation of prochiral ketones by transition metal complexes is one of the most effective methods for the synthesis of enantiomerically pure secondary alcohols,and is of great importance in the fields of pharmaceuticals,fine chemicals and advanced materials.In this paper,the chiral Ru complex containing achiral monophosphine ligand and chiral diamine ligand is synthesized and immobilized in ionic liquids.The resulting catalytic system is evaluated in the asymmetric hydrogenation of acetophenone.The effects of various reaction conditions including reaction temperature,hydrogen pressure,solvent,amount of ionic liquids,on the catalytic activity are studied in detail.The results show that the chiral catalyst can be effectively immobilized in ionic liquids,and low Ru leaching is found.The chiral catalyst can be separated simply by extraction.%过渡金属配合物催化的潜手性酮不对称加氢反应是制备手性仲醇的一个有效方法,在医药、精细化工及先进材料等领域具有非常重要的应用.采用离子液体-有机溶剂双液相体系,以手性二胺及非手性单膦配体修饰的Ru配合物为催化剂,催化潜手性酮的不对称加氢反应.考察了反应温度、氢气压力、溶剂和离子液体用量等因素对反应结果的影响,同时也考察了催化剂在反应体系中的流失情况.结果表明离子液体可以有效地负载手性催化剂,催化剂在反应过程中的流失量很低,可以实现简单的萃取分离.