A modular approach toward the synthesis of 2,4-disubstituted pyridines
摘要:
A number of 2,4-disubstituted pyridines have been synthesized using alpha,beta,gamma,delta-unsaturated aldehydes and ammonium chloride in the presence of triethylamine in acetonitrile solvent at 80 degrees C under air balloon. (C) 2013 Elsevier Ltd. All rights reserved.
N-Heterocyclic Carbene-Catalyzed δ-Carbon LUMO Activation of Unsaturated Aldehydes
作者:Tingshun Zhu、Chengli Mou、Baosheng Li、Marie Smetankova、Bao-An Song、Yonggui Robin Chi
DOI:10.1021/jacs.5b02219
日期:2015.5.6
An N-heterocyclic carbene (NHC) catalyzed domino reaction triggered by a delta-LUMO activation of alpha,beta-gamma,delta-diunsaturated enal has been developed for the formal [4 + 2] construction of multisubstituted arenes and 3-ylidenephthalide. These two products, formed in a highly chemo- and regioselective manner, were obtained via different catalytic pathways due to a simple change of the substrate. The activation of the remote delta-carbon of unsaturated aldehydes expands the synthetic potentials of NHC organocatalysis.