One-Pot Synthesis of 2,5-Diaryl 1,3,4-Oxadiazoles via Di-tert-butyl Peroxide Promoted N-Acylation of Aryl Tetrazoles with Aldehydes

Abstract

A metal- and base-free protocol for one-pot synthesis of 2,5-diaryl 1,3,4-oxadiazoles via a radical-promoted cross-dehydrogenative coupling strategy was developed. This reaction involved the N-acylation of aryl tetrazoles with aryl aldehydes, followed by thermal rearrangement. A wide range of aryl tetrazoles and aryl aldehydes survived the reaction conditions to deliver the corresponding products in moderate to good yields.

Palladium‐Catalyzed Aminocarbonylation Reaction to Access 1,3,4‐Oxadiazoles using Chloroform as the Carbon Monoxide Source

“…The N ‐containing heterocycles such as tetrazoles, however, have not been tried yet. Given that 1,3,4‐oxadiazoles are of great importance due to their wide applications in pharmaceutical chemistry13 and material science,14 and in continuation of our interest in heterocycles,12g herein, we report a palladium‐catalyzed aminocarbonylation reaction to access 1,3,4‐oxadiazoles by using chloroform as the carbon monoxide source.…”

Recent advances on oxadiazole motifs: Synthesis, reactions and biological activities

“…This route involved a one-pot radical-promoted crossdehydrogenative condensation between aryl tetrazoles (49) and aldehydes, starting from the N-acylation of the tetrazole, followed by thermal rearrangement that led to the expulsion of N2. This advantageous base and metalfree synthesis gave yields as high as 87% 63 .…”

Five-Membered Ring Systems

“…A one-pot synthesis of 2,5-diaryl-1,3,4-oxadiazoles 174 was accomplished from the di-tert-butylperoxide (DTBP) promoted N-acylation of aryl tetrazoles 173 with aromatic aldehydes (15JOC4743). Similarly, one-pot syntheses of 2,5-diaryl-1,3,4-oxadiazoles 174 were achieved from the palladium-catalyzed aminocarbonylation reaction of aryl iodides with chloroform and aryl tetrazoles 173, where chloroform was used as the carbon monoxide source in the presence of cesium hydroxide (15ASC3469).…”