Carboxyl Group-Directed Iridium-Catalyzed Enantioselective Hydrogenation of Aliphatic γ-Ketoacids
作者:Mao-Lin Li、Yao Li、Jia-Bin Pan、Yi-Hao Li、Song Song、Shou-Fei Zhu、Qi-Lin Zhou
DOI:10.1021/acscatal.0c02142
日期:2020.9.4
occurrence of chiral induction involving a hydrogen–hydrogen interaction between a hydride on the iridium atom and the substituent on the oxazoline ring of the ligand, and on the basis of the calculations, we proposed a catalytic cycle involving only Ir(III), which differs from the Ir(III)/Ir(V) catalytic cycle that operates in the hydrogenation of α,β-unsaturated carboxylic acids.
尽管已经广泛地研究了过渡金属催化的芳族酮的不对称氢化,但是脂肪族酮的对映选择性氢化仍然是一个挑战,因为手性催化剂不能轻易地区分这些酮的正反面。在这里,我们报道了脂肪族γ-酮酸不对称氢化的羧基导向策略。在具有手性螺膦-恶唑啉配体的铱配合物的催化下,脂肪族γ-酮酸的氢化得到具有高对映选择性(高达99%ee)的手性γ-羟基内酯。机理研究表明,底物的羧基指导氢转移并确保高对映选择性。