An N-heterocyclic carbene iridium catalyst with metal-centered chirality for enantioselective transfer hydrogenation of imines
作者:Yanjun Li、Meng Lei、Wei Yuan、Eric Meggers、Lei Gong
DOI:10.1039/c7cc04691j
日期:——
carbene iridium complex featuring metal-centered chirality was designed and applied to the asymmetric transfer hydrogenation (ATH) of imines. Four strongly σ-donating carbon-based substituents (2 carbenes and 2 phenyl moieties), a chirality transfer directly from the stereogenic metal center to the C=N bond of substrates, as well as a restriction of catalyst deactivation by steric demanding substituents
设计了具有金属中心手性的环金属化N-杂环卡宾铱配合物,并将其应用于亚胺的不对称转移氢化(ATH)。四个强σ供电的碳基取代基(2个碳烯和2个苯基部分),手性直接从立体金属中心转移至底物的C = N键,以及由于空间要求的取代基限制了催化剂的失活就催化剂的负载量(低至0.01 mol%),底物范围(24个实例)和对映选择性(94-98%ee)而言,这种新型的络合物是用于环N-磺酰亚胺的ATH的最有效的催化剂之一。