A Family of Thiazolium Salt Derived N-Heterocyclic Carbenes (NHCs) for Organocatalysis: Synthesis, Investigation and Application in Cross-Benzoin Condensation
作者:Isabel Piel、Marius D. Pawelczyk、Keiichi Hirano、Roland Fröhlich、Frank Glorius
DOI:10.1002/ejoc.201100870
日期:2011.10
A family of thiazolium salt derived N-heterocyclic carbenes (NHCs) bearing sterically demanding aryl substituents on the nitrogen and with varying backbone substitution patterns have been synthesized. Investigation of the catalytic activity of these NHCs in a number of benzoin-type coupling reactions revealed markedly different levels of reactivity and selectivity. To elucidate the underlying factors
已经合成了一系列噻唑鎓盐衍生的 N-杂环卡宾 (NHC),在氮上具有空间要求的芳基取代基并具有不同的骨架取代模式。对这些 NHC 在许多安息香型偶联反应中的催化活性的研究表明,反应性和选择性水平明显不同。为了阐明导致反应性差异的潜在因素,对这些 NHC 催化剂的电子和空间性质进行了研究。通过使用本研究中最好的催化剂,更详细地探索了分子间交叉安息香缩合反应。