An Eco‐friendly Catalytic System for One‐pot Multicomponent Synthesis of Diverse and Densely Functionalized Pyranopyrazole and Benzochromene Derivatives
作者:U. P. Patil、Rupesh C. Patil、Suresh S. Patil
DOI:10.1002/jhet.3564
日期:2019.7
An external base‐free, efficient, cost‐effective, and environmentally benign protocol has been developed for the one‐pot multicomponentsynthesis of highly functionalized pyranopyrazoles and benzochromenes using water extract of Agave americana (century plant) leaf ash, a waste‐derived catalyst, at roomtemperature. Mild reaction conditions, high yield, easy isolation of products, eco‐friendly standards
Diisopropyl azodicarboxylate mediated selective dehydrogenation of 2-amino-3-cyano 4 H -chromenes
作者:Himanshu Sharma、Mohini Mourya、Debanjan Guin、Yogesh C. Joshi、Mahabeer P. Dobhal、Ashok K. Basak
DOI:10.1016/j.tetlet.2017.03.049
日期:2017.5
Selective dehydrogenation of 2-amino-3-cyano 4H-chromenes to the corresponding 2-iminochromenes mediated by diisopropyl azodicarboxylate under neutral conditions is reported. The dehydrogenation reaction is compatible with phenolic hydroxyl group and generates iminochromene in high yields. The methodology provides an easy access to coumarin and N-tosyl 2-amino-3-cyano-4-aryl 4H-chromenes.