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-heterocycliccarbenes (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
A convenient and selective synthesis of unsymmetrical benzoins via the cyanide ion catalyzed cleavage of benzils
作者:Ayhan S Demir、Ömer Reis
DOI:10.1016/j.tet.2004.03.016
日期:2004.4
The cyanide ion-catalyzed cleavage of benzils is used for the generation of various ‘masked’ acyl intermediates. The reaction of these intermediates with various aldehydes furnishes the corresponding esters of unsymmetrical benzoins in very good yields. A variety of unsymmetrical benzoin derivatives are synthesized in this way, including ferrocene derivatives. The hydrolysis of benzoin esters and their