One-Pot Three-Component Approach to the Synthesis of Polyfunctional Pyrazoles
摘要:
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.
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.
Visible-Light-Mediated Synthesis of Pyrazines from Vinyl Azides Utilizing a Photocascade Process
作者:Asik Hossain、Santosh Pagire、Oliver Reiser
DOI:10.1055/s-0036-1590888
日期:2017.9
A convenient method for the synthesis of substituted pyrazines from vinylazides has been developed. This method is enabled by a dual-energy and electron-transfer strategy by visible-lightphotocatalysis. Initially, vinylazides are activated by a triplet sensitization process from an excited ruthenium photocatalyst in the presence of water to form dihydropyrazines, followed by a single-electron-transfer
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.