Transfer Hydrogenation of Ketones, Nitriles, and Esters Catalyzed by a Half-Sandwich Complex of Ruthenium
作者:Sun-Hwa Lee、Georgii I. Nikonov
DOI:10.1002/cctc.201402780
日期:2015.1
Half‐sandwich complexes [Cp(PiPr3)Ru(CH3CN)2]PF6 (1; Cp=cyclopentadienyl) and [Cp*(phen)Ru(CH3CN)]PF6 (2; Cp*=pentamethylcyclopentadienyl, phen=phenanthroline) catalyse the transfer hydrogenation of ketones to alcohols, aldimines to amines, and nitriles to imines under mild conditions. In the latter process, the imine products come from the coupling of the amines formed initially with acetone derived
半三明治复合物[Cp(P i Pr 3)Ru(CH 3 CN)2 ] PF 6(1 ; Cp =环戊二烯基)和[Cp *(phen)Ru(CH 3 CN)] PF 6(2; Cp * =五甲基环戊二烯基,phen =邻二氮杂菲)在温和条件下催化酮氢化氢化成醇,醛亚胺转化成胺,腈转化成亚胺。在后一种方法中,亚胺产物来自最初形成的胺与衍生自还原溶剂(异丙醇)的丙酮的偶联。在官能取代的腈中,醛基和酮基与氰基同时被还原,而酯基和酰胺基则被容忍。在这些条件下,即使加热到70°C,酰胺和烷基酯也不会还原。但是,苯甲酸苯酯和三氟乙酸盐被还原为醇。有关在异丙醇中还原苯乙酮的动力学研究表明,该反应在底物和醇中都是一级反应。化学计量的力学研究表明形成了氢化物。提出了氢化物机制来解释这些观察结果。