Copper-mediated three-component synthesis of 2-trifluoromethyl benzimidazoles

Abstract

A copper-mediated three-component reaction of o-iodoanilines, anilines, and ethyl trifluoropyruvate is reported. The transformation allows diverse scopes on both o-iodoanilines and anilines delivering various 2-trifluoromethylbenzimidazole products in moderate to good...

Recent Scenario for the Synthesis of Benzimidazole Moiety(2020–2022)

“…Here, the magnetic nature of Scheme 21. Cucurbit [6]uril-supported fe 3 o 4 magnetic nanoparticles catalysed green and sustainable synthesis of 2-substituted benzimidazole via acceptor and less dehydrogenative coupling. the nanocomposite enables an external magnet to recover the catalyst from the reaction mixture with relative ease.…”

“…On the basis of control experiments and isolated intermediates, a plausible reaction mechanism for 2‐trifluoromethylbenzimidazole synthesis is depicted in (scheme 3). [6] Initially, condensation of o‐iodoaniline 3 a with ethyl trifluoro pyruvate 3 c in the presence of a base yields intermediate 3 e , which forms intermediate 3 f with copper. The intermediate 3 f undergoes the intermolecular Ullmann‐type cross‐coupling reaction with aniline and forms intermediates, which by intramolecular amination through the Cu I /Cu III catalytic cycle produces the desired product in a sequential step.…”

Synthesis of 2-trifluoromethyl benzimidazoles, benzoxazoles, and benzothiazoles via condensation of diamines or amino(thio)phenols with CF3CN

“…Our own interest in the synthesis of 2-(trifluoromethyl)benzimidazolo-fused heterocycles results from our recent work describing a one-pot synthesis of 2-trifluoromethylbenzimidazoles through a copper-mediated three-component reaction. 29 Also, we have recently demonstrated new efficient protocols for assembling a range of novel five-membered nitrogen-containing heterocycles using in situ generated trifluoroacetonitrile from 2,2,2-trifluoroacetaldehyde O-(aryl)oxime. [30][31][32][33] On the basis of these previous studies, especially on the synthesis of benzothiazoles and their structural analogues by the condensation of 2-aminothiophenol and nitriles, [34][35][36] and our continued interest in trifluoromethylated heterocycle synthesis, [37][38][39][40][41] we further became interested in designing efficient methodologies for the synthesis of 2-trifluoromethyl benzimidazoles and benzothiazoles via condensation of diamines or amino(thio)phenols with CF 3 CN (Scheme 1b).…”

Copper‐Catalyzed One‐Pot Arylation and Cyclization of Diaryliodonium Salts Derived fromo‐Iodoanilines for Indolo[2,3‐b]indoles Syntheses

“…[12] Very recently, a three-component reaction employing o-iodoanilines has been reported to get 2-trifluoromethylbenzimidazoles by Weng and co-workers. [13] We envisioned that, by enhancing arylation capability and utilizing bifunctional reactivity, the diaryliodonium salts, prepared from o-iodoanilines could be employed in many ways for the synthesis of versatile heterocycles. One of the fused indole skeletons, indolo-[2,3-b]indole, was selected for the verification of our hypothesis.…”

“…In 2006, Zhu and colleagues extended the synthetic utility of 2‐iodoanilines with aldehydes in the construction of indoles [12] . Very recently, a three‐component reaction employing o ‐iodoanilines has been reported to get 2‐trifluoromethylbenzimidazoles by Weng and co‐workers [13] . We envisioned that, by enhancing arylation capability and utilizing bifunctional reactivity, the diaryliodonium salts, prepared from o ‐iodoanilines could be employed in many ways for the synthesis of versatile heterocycles.…”