Chiral Quaternary Ammonium Aryloxide/<i>N,O</i>-Bis(trimethyl- silyl)acetamide Combination as Efficient Organocatalytic System for the Direct Vinylogous Aldol Reaction of (<i>5H</i>)-Furan-2-one Derivatives
作者:Aurélie Claraz、Sylvain Oudeyer、Vincent Levacher
DOI:10.1002/adsc.201201041
日期:2013.3.25
A chiral quaternary ammonium amide was generated in situ from N,O‐bis(trimethylsilyl)acetamide (BSA) as non‐nucleophilic Brønsted base precursor and the combination of chiral quaternary ammonium halide/sodium aryloxide as chiral Lewis base. This system was applied to an anti‐selective organocatalytic direct vinylogous aldol (ODVA) reaction of (5H)‐furan‐2‐one derivatives with aldehydes. Several 5‐
的手性季铵酰胺生成原位从N,O二(三甲基硅烷基)乙酰胺(BSA)作为非亲核布朗斯泰德碱前体和手性季铵卤化物/钠芳醚作为手性路易斯碱的组合。该系统用于(5 H)-呋喃-2-酮衍生物与醛的抗选择性有机催化直接乙烯基醇醛(ODVA)反应。与脂肪族或(杂)芳族醛类均以良好的非对映异构体比例(最高95/5)和出色的对映选择性(最高94%)获得了几种5-(1'-羟基)-γ-丁烯内酯,因此提供了一个罕见的例子ODVA反应的一般有效条件。