Cascade Wolff Rearrangement/Acylation: A Metal-Free and Eco-Friendly Approach for 4-Hydroxy-pyrazolo[3,4-<i>b</i>]pyridin-6-ones and <i>N</i>-Pyrazole Amides Synthesis from 5-Aminopyrazoles and α-Diazoketones
Xiangjin Zhang, Jie Zhang, Yuning Xu, Yi‐Ming Li, Man Chi, Yu Yan, Ruixue Wu, Huiru Zhang, Yanping Zhu
Abstract
A highly chemoselective cascade Wolff rearrangement/acylation reaction between 5-aminopyrazoles and diazo compounds has been developed. The protocol can facilitate the switchable synthesis of 4-hydroxy-pyrazolo[3,4-b]pyridin-6-ones and N-pyrazole amides with the merits of a broad substrate scope, high functional group compatibility, and green and sustainable performance manner. All reactions proceeded efficiently without any catalyst and additives (acid and base) and resulted in the release of benign N2, wherein diethyl carbonate served as a green benign solvent.
Topics & Concepts
ChemistryPyrazoleAcylationDiazoCascade reactionCombinatorial chemistryCatalysisFunctional groupGreen chemistryOrganic chemistryAmideSolventReaction mechanismPolymerCyclopropane Reaction MechanismsSynthesis and Biological EvaluationCatalytic C–H Functionalization Methods