Synthesis of Substituted 1,2-Dihydropyridines from Propargyl Vinyl Ethers and Allenic Vinyl Ethers by Gold-Catalyzed Claisen Rearrangement and 6π-Aza-electrocyclization
作者:Hao Wei、Yao Wang、Bin Yue、Peng-Fei Xu
DOI:10.1002/adsc.201000292
日期:2010.10.4
An efficient synthetic method was developed for the construction of substituted 1,2-dihydropyridines by gold-catalyzed tandem reactions. The key intermediates 2,4-dienals were generated from propargyl vinyl ethers or allenic vinyl ethers with gold catalysts. These two reactions involved the process of gold-catalyzed [3,3]-sigmatropic rearrangement/isomerization/amine condensation/6π-aza-electrocyclization
All at once: Microwave irradiation of a metal‐free mixture of propargyl enolethers and primary amines generates substituted alkyl 1,2‐dihydropyridine‐3‐carboxylates in excellent yields through a domino process (see scheme). The obtained 1,2‐dihydropyridines feature four possible diversity points and a chemical handle for complexity‐diversity generation (carboxylic ester at the C3 position).