Step- and atom-economical synthesis of 2-aryl benzimidazoles via the sulfur-mediated redox condensation between o-nitroanilines and aryl methanols

Le, Hai Son; Nguyen, Khoa D.; Phan, Nam T. S.; Le, Ha V.; Nguyen, Tung T.

doi:10.1016/j.tet.2022.132918

Cited by 4 publications

(1 citation statement)

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“…Very recently, we developed a sulfur-mediated redox condensation towards 2-substituted benzimidazoles from ortho-nitroanilines and alcohols. [30] Following our efforts to expand the synthetic approach to these compounds and previous reports about the construction of CÀ N and CÀ C bonds through MPVÀ O strategy, we herein reported an environmentally benign one-pot strategy of base-catalyzed cyclization starting from ortho-nitroanilines and benzyl alcohols (Scheme 2). Such approach features the approach which do not require the use of transition metals.…”

Section: Introductionmentioning

confidence: 99%

t‐BuONa‐Mediated Redox Condensation between o‐Nitroanilines and Benzyl Alcohols towards 2‐Phenyl Benzimidazoles under Transition‐Metal‐Free Conditions

Phan

et al. 2023

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A novel and environmentally benign method was developed for the direct synthesis of 2‐substituted benzimidazoles via a transition metal‐free redox tandem annulation of benzyl alcohols and ortho‐nitroanilines in the presence of a strong base, e.g. alkaline alkoxides or hydroxides. A good tolerance of functional groups was observed, affording an array of 2‐aryl benzimidazole derivatives in high yields. Early mechanistic studies showed that sodium tert‐butoxide could initiate the hydrogen transfer from benzyl alcohol to the nitro group in ortho‐nitroaniline followed by imine condensation, cyclization, and oxidation. This protocol features a convenient tactic that does not require any external oxidants or solvents for the synthesis of bioactive benzimidazole‐involving compounds.

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Section: Introductionmentioning

confidence: 99%