Intramolecular decarboxylative coupling as the key step in copper-catalyzed domino reaction: facile access to 2-(1,3,4-oxadiazol-2-yl)aniline derivatives

Abstract

A copper-catalyzed domino protocol for the synthesis of 2-(1,3,4-oxadiazol-2-yl)aniline derivatives has been developed from simple and available isatins and hydrazides. This domino process integrated consecutive condensation, base-promoted ring-opening and the key copper-catalyzed decarboxylative coupling for intramolecular C-O bond formation.

The preparation, characterization and catalytic activity of Ni NPs supported on porous alginate-g-poly(p-styrene sulfonamide-co-acrylamide)

“… 1 They represent the core structure of several antitumor and anti-HIV drugs on the market, including zibotentan, 2 and raltegravir. 3 Hence, some methods have recently been reported for the synthesis of 1,3,4-oxadiazoles, such as the annulation of methyl ketones or acyl chlorides with hydrazides, 4 the cyclization of 1,2-diacylhydrazines, 5 the cyclization of acylhydrazones, 6 imine C–H bond activation of N -arylidenearoylhydrazide, 7 arylation of the 1,3,4-oxadiazoles, 8 intramolecular decarboxylation, 9 and the isocyanide insertion reaction. 10 However, some of these require harsh reaction conditions, and expensive noble and precious metal-based catalyst systems which results in increased production costs owing to the difficultly in separating the desired products.…”

Iodine-mediated one-pot intramolecular decarboxylation domino reaction for accessing functionalised 2-(1,3,4-oxadiazol-2-yl)anilines with carbonic anhydrase inhibitory action

“…Recently, Xu et al. demonstrated an easy access to synthesise 2-(1,3,4-oxadiazol-2-yl)anilines by employing CuI as the catalyst 20 . Nevertheless, the problems associated with these protocols, including the use of expensive, hazardous materials, or inefficient multi-step processes endowed them with a limited applicability.…”

1,3,4-Oxadiazole and Heteroaromatic-Fused 1,2,4-Triazole Synthesis­ Using Diverted Umpolung Amide Synthesis

“…1 Another large group of approaches involve oxidative transformations of an aromatic heterocycle’s precursor. 2 Syntheses of both 1,3,4-oxadiazoles 3,4,5 and 1,2,4-triazoles largely fall into these two categories. 6 Collectively, these approaches often invoke the use of highly electrophilic reagents or strong oxidants, and some have noted the inefficient nature (i.e.…”