Cyclometalated Complexes of Ruthenium, Rhodium and Iridium as Catalysts for Transfer Hydrogenation of Ketones and Imines
作者:Nicolas Pannetier、Jean-Baptiste Sortais、Jean-Thomas Issenhuth、Laurent Barloy、Claude Sirlin、Alexandre Holuigue、Laurent Lefort、Lavinia Panella、Johannes G. de Vries、Michel Pfeffer
DOI:10.1002/adsc.201100152
日期:2011.10
[Ar(CO)R′′ in which R′′ is a tertiary alkyl group] the best catalyst was a ruthenium compound derived from bis[(R)-1-phenylethyl]amine, allowing the reduction of isobutyrophenone and cyclohexyl phenyl ketone which were both reduced with high enantioselectivities (ees up to 98%). This shows that the cyclometalated compounds have a high substrate specificity. In addition, acyclic and cyclic imines were reduced
在许多酮和亚胺的不对称转移氢化中,测试了由被钌(II),铑(III)和铱(III)环化的伯胺和仲胺衍生的有机金属化合物库。所有化合物在温和条件下均表现出高催化活性,可还原酮。对映选择性最高的催化剂是基于含两个与氮原子键合的不对称碳原子的仲胺。为了还原芳基烷基酮[Ar(CO)R,其中R = CH 3或CH 2 R'],(2 R,5 R)-2,5-二苯基吡咯烷配体的环金属化钌和铑衍生物表现出最佳结果相对于活性和选择性(EE最高可达97%)。然而,为了还原芳基叔烷基酮[Ar(CO)R′,其中R′′是叔烷基],最好的催化剂是衍生自双[(R)-1-苯基乙基]胺的钌化合物。,可以还原异丁苯酮和环己基苯基酮,它们都以高对映选择性(ee高达98%)被还原。这表明环金属化的化合物具有高的底物特异性。此外,用(2 R,5 R)-2,5-二苯基吡咯烷酮构建的铑(III)和铱(III)金属环都以良好的选择性还原了无环和环状亚胺。