Novel Base-Free Catalytic Wittig Reaction for the Synthesis of Highly Functionalized Alkenes
作者:Marie-Luis Schirmer、Sven Adomeit、Anke Spannenberg、Thomas Werner
DOI:10.1002/chem.201503744
日期:2016.2.12
base‐free catalytic Wittig reactions has been developed and optimized. Initially, several potential (pre)catalysts as well as different silanes as reducing agents were screened. A system based on a readily available phosphine oxide as precatalyst and trimethoxy silane as reducing agent proved to be optimal. The effect of various Brønsted acidic additives was studied. Subsequently, the reaction conditions were
已开发并优化了一种用于无碱催化Wittig反应的高效催化剂体系。最初,筛选了几种潜在的(预)催化剂以及不同的硅烷作为还原剂。基于容易获得的氧化膦作为前催化剂和三甲氧基硅烷作为还原剂的体系被证明是最佳的。研究了各种布朗斯台德酸性添加剂的效果。随后,优化反应条件并确定标准反应条件。在这些条件下,对该新协议的范围进行了评估。将九种活化烯烃和33种醛转化为42种高度官能化的烯烃。值得注意的是,可以将芳族,脂族和杂芳族醛进行转化,从而以高达99%的分离产率得到所需产物,并具有良好至优异的分离度。E / Z选择性。考虑到反应混合物的复杂性以及在一个罐中并行进行的四个反应步骤,这些结果强调了该方案的显着效率。