Asymmetric Darzens-type epoxide formation of aryl aldehydes with chiral para-substituted benzylammonium ylides, prepared from brucine and corresponding benzylic chlorides and treated in situ under basic condition, was carried out to afford chiral 2,3-diaryl epoxides with moderate to good ee (84% ee). Brucine was found to be an excellent tertiary amine for a chirality transfer agent.
由马钱子碱和相应的氯化苄制备并在碱性条件下原位处理,与手性对位取代的苄基铵叶立德形成芳基醛的不对称 Darzens 型环氧化物,得到具有中等至良好 ee 的手性 2,3-二芳基环氧化物( 84% ee)。研究发现马钱子碱是一种优异的手性转移剂叔胺。