pyrrole formation by the reaction of vinylazides with 1,3-dicarbonyl compounds via the 1,2-addition of 1,3-dicarbonyl compounds to 2H-azirine intermediates generated in situ from vinylazides; (ii) the Cu(II)-catalyzed synthesis of pyrroles from alpha-ethoxycarbonyl vinylazides and ethyl acetoacetate through the 1,4-addition reaction of the acetoacetate to the vinylazides. By applying these two methods
Simple and eco-friendly synthesis of polyfunctionalized 2-aminopyrroles from vinyl azides and α-cyano derivatives has been accomplished with a good to excellent yield. The reaction was performed in ethanol/water co-solvent system without catalyst and the workup was facile. A plausible mechanism has been proposed.
A Tandem Approach to Isoquinolines from 2-Azido-3-arylacrylates and α-Diazocarbonyl Compounds
作者:Yun-Yun Yang、Wang-Ge Shou、Zheng-Bo Chen、Deng Hong、Yan-Guang Wang
DOI:10.1021/jo8003259
日期:2008.5.1
2-Azido-3-arylacrylates react with α-diazocarbonyl compounds and triphenylphosphine to furnish isoquinolines in 60−92% yields. The tandem process involves a Wolff rearrangement, an aza-Wittig reaction, and an electrocyclic ringclosure. The procedure is efficient, rapid, and general, and the substrates are readily available.
A simple, multicomponent, and straightforward reaction of vinyl azide, aldehyde, and tosylhydrazine affords the construction of 3,4,5-trisubstituted 1H-pyrazoles regioselectively in the presence of base with moderate to excellent yields. A range of functionality could be tolerated in this methodology, and a possible mechanism is proposed.