An efficient and environmentally benign electrosynthesis of 2,5‐disubstituted 1,3,4‐oxadiazoles from α‐ketoacids and acylhydrazines under metal‐free and external oxidant free conditions has been developed. A broad range of acylhydrazines and α‐ketoacids were compatible, and the reaction could be conducted in gram scale with high reaction efficiency.
The copper-mediated direct arylation of 1,3,4-oxadiazoles and 1,2,4-triazoles with aryl iodides proceeds efficiently in the presence of suitable ligands and bases. This method allows the installation of a variety of aryl moieties bearing a functional group such as ketone, ester, or nitrile so as to enable the facile construction of various functionalized oxadiazole and triazole core π systems.
A practical and transition-metal-freeoxidative cyclization of acylhydrazones into 1,3,4-oxadiazoles has been developed by employing stoichiometric molecular iodine in the presence of potassium carbonate. The conditions of this cyclization reaction also work well with crude acylhydrazone substrates obtained from the condensation of aldehydes and hydrazides. A series of symmetrical and asymmetrical
Direct Palladium‐Catalyzed C5‐Arylation of 1,3,4‐Oxadiazoles with Aryl Chlorides Promoted by Bis(di‐isopropylphosphino) Ferrocene
作者:Loris Gelin、Henri Sabbadin、Hélène Cattey、Paul Fleurat‐Lessard、Jean‐Cyrille Hierso、Julien Roger
DOI:10.1002/ejoc.202400212
日期:2024.6.3
The palladium-catalyzed direct arylation of 1,2,4-oxadiazoles proceeds efficiently at low catalyst loading (0.5 to 1 mol %) with the decisive assistance of sterically constrained ferrocenyldiphosphane ligands. This protocol tolerates electron-donating and electron-withdrawing substituents on the (heteroaryl)arylhalide.