Copper-Catalyzed N-Arylation of Azoles and Mannich-Type Coupling of Ketones and Azoles under Metal-Free Conditions

Abstract

A new process has been developed for the copper-catalyzed direct N-arylation of five-membered heterocycles with azoles. Five-membered heterocycles bearing an acetyl group also underwent a Mannich-type reaction with activated azoles to give the corresponding β-amino ketones under metal-free conditions. These reactions exhibited wide substrate scope, high functional group tolerance, and ease of operation, making them useful tools with numerous potential applications in synthetic chemistry.

Ni‐Catalyzed Synthesis of Methylenebisamides: Dual Role of DMSO Both as Methylene Source and Oxidant

“…These results are very good evidences for the mechanism presented in Scheme for the formation of methylene bisbenzamidederivatives . At first stage, hydrolysis of benzonitriles to the corresponding benzamides occurs in the presence of acetic acid to form typical benzamide A .…”

Synthesis of symmetrical methylene-bridged imidazoheterocycles using DMSO as methylene source under metal-free conditions

“…4 Extensive studies for the functionalization of imidazopyridines on the same position were reported in recent years, in which most efforts were focused on introducing sulfur-5 or fluorine-containing groups 6 for the consideration of the potential application in pharmaceutical synthesis. 15 We have recently reported a route to methylene-bridged arylamines in the presence of NH 4 I/DMSO, in which DMSO was proved to be the efficient methylene source. 7 When we tried to perform the trifluoromethylthiolation of imidazo [1,2-a]pyridine with CF 3 SO 2 Na, an unexpected methylene-bridged product bis(2phenylimidazo [1,2-a]pyridin-3-yl)methane (2a) was obtained in 55% yield.…”

Metal‐Free Synthesis of Methylene‐Bridged Bisamide via Selectfluor‐Mediated Oxidative Methylenation

“…The postulated mechanism of this transformation was proposed in Scheme on the basis of the received results and previous literature reports ,[10] . Initially, DMSO is converted into α‐fluorinated intermediate A or methyl(methylene)sulfonium cation A’ promoted by Selectfluor.…”