AbstractA series of air‐stable Mn complexes bearing NNS pincer ligands have been synthesized and fully characterized. The activity of the complexes as (transfer) hydrogenation catalysts was investigated in detail, and a variety of ketones (>20 examples) were converted to the corresponding secondary alcohols at room temperature. The synthetic applicability of this class of catalysts is demonstrated by the tolerance of several functional groups including halides, primary amines, nitriles, esters, and nitro‐groups. Moreover, the optimal catalytic system 5c displayed a high chemoselectivity in the presence of other reducible groups such as nitriles, esters, and alkynes. Competitive catalytic experiments with the analogous bidentate NN complex 8 indicated decoordination of the hemilabile thioether‐moiety during formation of the catalytically active hydrido species.
摘要 我们合成了一系列具有 NNS 钳子
配体的空气稳定
锰配合物,并对其进行了全面表征。研究人员详细考察了这些配合物作为(转移)
氢化
催化剂的活性,并在室温下将多种
酮类(20 个实例)转化为相应的仲醇。这类
催化剂对多种官能团(包括卤化物、
伯胺、腈、
酯和硝基)的耐受性证明了其合成适用性。此外,最佳催化体系 5c 在腈类、
酯类和炔类等其他可还原基团的存在下也显示出很高的
化学选择性。与类似的双齿 NN 复合物 8 进行的竞争性催化实验表明,在形成具有催化活性的
氢化物的过程中,半乳
硫醚分子发生了
脱配位。