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Upstream product

• 22019-66-5 4-methyl-2-nitro-N-benzylaniline 
• 100-52-7 benzaldehyde 
• 89-62-3 4-methyl-2-nitroaniline 
• 100-39-0 benzyl bromide 
• 103-49-1 dibenzylamine 
• 100-51-6 benzyl alcohol 
• 496-72-0 4-methyl-1,2-diaminobenzene 
• 55-21-0 benzamide 
• 809231-03-6 N-benzyl-2-bromo-4-methylbenzeneamine 
• 583-68-6 2-bromo-p-toluidine 
• 582-77-4 3'-methylbenzanilide 
• 93-98-1 N-phenyl benzoyl amide 
• 1609460-38-9 N-benzyl-N′-(m-tolyl)benzimidamide 
• 46721-83-9 N-(chloro(phenyl)methylene)(phenyl)methanamine 

Relevant academic research and scientific papers

Electrochemical Synthesis of Benzo[ d]imidazole via Intramolecular C(sp3)-H Amination

An electrochemical dehydrogenative amination for the synthesis of benzimidazoles was developed. This electrosynthesis method could address the limitations of the C(sp3)-H intramolecular amination synthesis reaction and provide novel access to obtain 1,2-disubstituted benzimidazoles without transition metals and oxidants. Under undivided electrolytic conditions, various benzimidazole derivatives could be synthesized, exhibiting functional group tolerance.

Nickel catalyzed sustainable synthesis of benzazoles and purines: Via acceptorless dehydrogenative coupling and borrowing hydrogen approach

Herein we report nickel-catalyzed sustainable synthesis of a few chosen five-membered fused nitrogen heterocycles such as benzimidazole, purine, benzothiazole, and benzoxazole via acceptorless dehydrogenative functionalization of alcohols. Using a bench stable, easy to prepare, and inexpensive Ni(ii)-catalyst, [Ni(MeTAA)] (1a), featuring a tetraaza macrocyclic ligand (tetramethyltetraaza[14]annulene (MeTAA)), a wide variety of polysubstituted benzimidazole, purine, benzothiazole, and benzoxazole derivatives were prepared via dehydrogenative coupling of alcohols with 1,2-diaminobenzene, 4,5-diaminopyrimidine, 2-aminothiphenol, and 2-aminophenol, respectively. A wide array of benzimidazoles were also prepared via a borrowing hydrogen approach involving alcohols as hydrogen donors and 2-nitroanilines as hydrogen acceptors. A few control experiments were performed to understand the reaction mechanism.

Water extract of onion catalyst: An economical green route for the synthesis of 2-substituted and 1,2-disubstituted benzimidazole derivatives with high selectivity

An efficient, environmental friendly and substrate controlled method of synthesis of 2-substituted benzimidazole derivatives 3 and 1,2-disubstituted benzimidazole derivatives 4 with high selectivity has been achieved from the reaction of o-phenylenediamine 1 and aldehydes 2 in the presence of water extract of onion and selecting suitable reaction medium. This method is widely applicable for variety of aldehydes such as aromatic/aliphatic/heterocyclic aldehydes and 1,2-diamines to afford 2-substituted benzimidazole derivatives 3 and 1,2-disubstituted benzimidazole derivatives 4 in good to excellent yields (up to 96%). The developed method of water extract of onion catalysis produced 2-substituted benzimidazoles 3 from aromatic aldehydes having electron-withdrawing groups, whereas aromatic aldehydes bearing electron donating groups selectively furnished 1,2-disubstituted benzimidazole 4 derivatives. The process described here has several advantages of cheap, low energy consumption, commercially available starting materials, operational simplicity and nontoxic catalyst. The use of water extract of onion makes this present methodology green and giving a useful contribution to the existing methods available for the preparation of benzimidazole derivatives. In addition, Hammett correlation of substituent constant (σ) vs percentage (%) yield has been established.

Heterogenizing a Homogeneous Nickel Catalyst Using Nanoconfined Strategy for Selective Synthesis of Mono- And 1,2-Disubstituted Benzimidazoles

A homogeneous Ni-phenanthroline catalyst was successfully immobilized into the cavities of a metal-organic framework, ZIF-8. The as-synthesized heterogeneous catalyst, Ni-Phen@ZIF, represents the first MOF based catalyst that enables dehydrogenative coupling of alcohols with aromatic diamines for selective synthesis of both mono- and 1,2-disubstituted benzimidazoles. The catalyst survived under harsh basic conditions, characterized by SEM, TEM, BET, PXRD, and EDX elemental mappings. The presence of the nanoconfined Ni-phenanthroline complex and the formation of extra Lewis acid sites during catalysis in the Ni-Phen@ZIF structure, confirmed by TPD analysis and kinetic experiments, might be responsible for higher activity and selectivity.

Nickel-catalysed dehydrogenative coupling of aromatic diamines with alcohols: Selective synthesis of substituted benzimidazoles and quinoxalines

The first nickel-catalysed dehydrogenative coupling of primary alcohols and ethylene glycol with aromatic diamines for selective synthesis of mono- and di-substituted benzimidazoles and quinoxalines is reported. The earth-abundant, non-precious and simple NiCl2/L1 system enables the synthesis of N-heterocycles releasing water and hydrogen gas as byproducts. Mechanistic studies involving deuterium labeling experiments and quantitative determination of hydrogen gas evaluation were performed.

Bimetallic Cu-Mn B spinel oxide catalyzed oxidative synthesis of 1,2-disubstituted benzimidazoles from benzyl bromides

Cu-Mn B (a heterogeneous catalyst) catalyzed synthesis of 1-benzyl-2-phenyl-1H-benzo[d]imidazoles is reported. In this reaction, 2-phenyl-1H-benzo[d]imidazoles are found to be the side products. The reported protocol is simple and highly efficient, tolerates a wide variety of substrates and the products were formed in good to excellent yield.

One-pot strategy of copper-catalyzed synthesis of 1,2-disubstituted benzimidazoles

A simple, one-pot and copper-catalyzed coupling reaction for the construction of 1,2-disubstituted benzimidazole derivatives is described. A low-cost copper salt and a weak base K3PO4 were utilized in this reaction. A variety of 1,2-disubstituted benzimidazoles were obtained in moderate to excellent yields.

Solvent/oxidant-switchable synthesis of multisubstituted quinazolines and benzimidazoles via metal-free selective oxidative annulation of arylamidines

A fast and simple divergent synthesis of multisubstituted quinazolines and benzimidazoles was developed from readily available amidines, via iodine(III)-promoted oxidative C(sp3)-C(sp2) and C(sp 2)-N bond formation in nonpolar and polar solvents, respectively. Further selective synthesis of quinazolines in polar solvent was realized by TEMPO-catalyzed sp3C-H/sp2C-H direct coupling of the amidine with K2S2O8 as the oxidant. No metal, base, or other additives were needed.

"All-water" one-pot diverse synthesis of 1,2-disubstituted benzimidazoles: Hydrogen bond driven 'synergistic electrophile-nucleophile dual activation' by water

A new "all-water" tandem arylaminoarylation/arylaminoalkylation- reduction-cyclisation route is reported for one-pot diversity oriented synthesis of regiodefined 1,2-disubstituted benzimidazoles. Water plays a crucial and indispensable role through hydrogen bond driven 'synergistic electrophile-nucleophile dual activation' in the formation of N-mono-aryl/aryl alkyl/alkyl/cycloalkyl o-nitroanilines under metal and base-free conditions to replace the transition metal-based C-N bond formation (aryl amination) chemistry and underlines the origin of regiodefined installation of the diverse selection of aryl, aryl alkyl, and alkyl/cycloalkyl groups as substituents on the benzimidazole scaffold to form the 1,2-disubstituted benzimidazoles. The influence of the hydrogen bond effect of water in promoting the arylaminoarylation reaction under base and metal-free conditions has been realized through observation of inferior yields in D2O compared to that obtained in water during the reaction of o-fluoronitrobenzene with aniline separately performed in water and D2O under similar experimental conditions. Water also provides assistance in promoting the subsequent nitro reduction and in the final cyclocondensation steps. The role of water in promoting the cyclocondensation reaction through hydrogen bonds is realized by the differential product yields during the reaction of mono-N-phenyl-o- phenylenediamine with benzaldehyde performed separately in water and D 2O. The better hydrogen bond donor and hydrogen bond acceptor abilities of water compared to those of the organic solvents are the contributing/deciding factors for making the new water-assisted tandem arylaminoarylation/arylaminoalkylation-reduction-cyclisation strategy for the diversified synthesis of the regiodefined 1,2-disubstituted benzimidazoles effective in an aqueous medium, making it represent a true "all-water chemistry."

A one-pot synthesis of bisarylhydrazones by Cu(I)-catalyzed aerobic oxidation

An efficient Cu(I)-catalyzed one-pot synthesis of N-substituted (or NH) bisarylhydrazones is reported. A further cyclization reaction could occur towards the synthesis of benzimidazoles or triazoles with elevated temperature. A plausible alkylation-oxidation-alkylation mechanism is proposed based on experimental results and literature.