cases to afford the reduced compounds almost quantitatively with modest to good enantioselectivity (up to 72% ee). It was found that the Pd–iPr-DUPHOS complex was more reactive than the previously reported Pd–BINAP complex when molecular sieves 4A was added as an additive. Based on an X-ray structural analysis of [Pd(S,S)-iPr-duphos}](OTf)2 complex, a working hypothesis of the reaction mechanism is also
我们在此描述使用新型阳离子Pd – i Pr-D
UPHOS络合物的α,β-不饱和羰基化合物的催化不对称共轭还原。在该反应中,EtOH很好地用作溶剂和还原剂,并且在大多数情况下,反应在数小时内完成,从而几乎定量地得到还原的化合物,具有中等至良好的对映选择性(最高ee为72%)。发现当添加
分子筛4A作为添加剂时,Pd- i Pr-D
UPHOS复合物的反应性比以前报道的Pd-BINAP复合物高。基于[Pd (S,S)-i Pr-d
UPhOS}](OTf)2的X射线结构分析 复杂的,还描述了反应机理的有效假设。