Highly Active Metal-Free Catalysts for Hydrogenation of Unsaturated Nitrogen-Containing Compounds
作者:Victor Sumerin、Konstantin Chernichenko、Martin Nieger、Markku Leskelä、Bernhard Rieger、Timo Repo
DOI:10.1002/adsc.201100206
日期:2011.8
New highly active ansa-ammonium borate catalysts for the direct metal-free hydrogenation of imines were prepared by tuning of the basicity and steric bulkiness of their amine moieties. The highest catalytic activity among previously reported organocatalytic systems was shown for a wide range of nitrogen-containing substrates. The first example of asymmetric imine hydrogenation based on the ansa-ammonium
通过调节胺部分的碱度和空间体积,制备了用于亚胺直接无金属加氢的新型高活性ansa-硼酸铵催化剂。在先前报道的有机催化体系中,对于各种含氮底物显示出最高的催化活性。演示了基于ansa-硼酸铵概念的不对称亚胺加氢的第一个例子。此外,还阐述了通过用有机溶剂萃取酸性溶液,然后用TMSBr脱水来有效回收催化剂的方法。最初的发现强调了对映选择性氢化更有效的手性ansa-硼酸铵的开发。因此,在Ansa-硼酸铵的概念使其有希望进一步精加工,以期获得工业上适用的催化剂。