N-Heterocyclic Carbene-Catalyzed Reaction of Alkynyl Aldehydes with 1,3-Keto Esters or 1,3-Diketones
作者:Zhi-Qiang Zhu、Ji-Chang Xiao
DOI:10.1002/adsc.201000240
日期:2010.10.4
The N-heterocyclic carbene-catalyzed reaction of alkynyl aldehydes with 1,3-keto esters or 1,3-diketones has been studied. This protocol offers an entirely new, mild and atom-economical access to highly functionalized 3,4-dihydropyranones.
Polyhalides as Efficient and Mild Oxidants for Oxidative Carbene Organocatalysis by Radical Processes
作者:Xingxing Wu、Yuexia Zhang、Yuhuang Wang、Jie Ke、Martin Jeret、Rambabu N. Reddi、Song Yang、Bao-An Song、Yonggui Robin Chi
DOI:10.1002/anie.201611692
日期:2017.3.6
Simple and inexpensive polyhalides (CCl4 and C2Cl6) have been found to be effective and versatile oxidants in removing electrons from Breslow intermediates under N‐heterocyclic carbene (NHC) catalysis. This oxidative reaction involves multiple single‐electron‐transfer (SET) processes and several radical intermediates. The α, β, and γ‐carbon atoms of aldehydes and enals could be readily functionalized
Direct β-Activation of Saturated Aldehydes to Formal Michael Acceptors through Oxidative NHC Catalysis
作者:Junming Mo、Liang Shen、Yonggui Robin Chi
DOI:10.1002/anie.201302152
日期:2013.8.12
mediated by N‐heterocyclic carbenes (NHCs) enables the direct β‐carbon functionalization of saturated aldehydes (see scheme). The reaction proceeds through two sequential oxidative steps to generate α,β‐unsaturated triazolium ester equivalents as formal Michael acceptors, which react with 1,3‐diketones and β‐ketone esters in an enantioselective manner.