Asymmetric Hydrogenation of α,β-Unsaturated Nitriles with Base-Activated Iridium N,P Ligand Complexes
作者:Marc-André Müller、Andreas Pfaltz
DOI:10.1002/anie.201402053
日期:2014.8.11
Although many chiral catalysts are known that allow highly enantioselective hydrogenation of a wide range of olefins, no suitable catalysts for the asymmetric hydrogenation of α,β‐unsaturated nitriles have been reported so far. We have found that Ir N,P ligand complexes, which under normal conditions do not show any reactivity towards α,β‐unsaturated nitriles, become highly active catalysts upon addition
尽管已知许多手性催化剂可以对多种烯烃进行高度对映选择性氢化,但迄今为止,尚未见有合适的催化剂可用于α,β-不饱和腈的不对称氢化。我们发现,在正常条件下对N,N-二异丙基乙胺加成的Ir N,P配位体络合物在对α,β-不饱和腈没有反应性的情况下变成高活性催化剂。碱活化的催化剂可以使H,2的α,β-不饱和腈共轭还原在低催化剂负载量下,可获得具有高转化率和出色对映选择性的相应饱和腈。相反,缺乏共轭氰基的烯烃在这些条件下不会发生反应,因此可以选择性还原α,β-不饱和腈的共轭CC键,而分子中其他类型的CC键则完好无损。 。