717-57-7

Upstream product

• 64-17-5 ethanol 
• 100-52-7 benzaldehyde 
• 95-54-5 1,2-diamino-benzene 
• 100-51-6 benzyl alcohol 
• 41013-30-3 2,2'-[(1S,2S)-1,2-diphenyl-1,2-ethanediylbis(nitrilomethylidyne)]diphenol 
• 5822-13-9 N-benzyl-1,2-phenylenediamine 
• 127896-76-8 N-(1-chlorobenzyl)pyridinium chloride 

Downstream Products

• 716-79-0 2-phenyl-1H-benzoimidazole 
• 739-88-8 1-benzyl-2-phenyl-1H-1,3-benzimidazole 
• 5822-13-9 N-benzyl-1,2-phenylenediamine 
• 95-54-5 1,2-diamino-benzene 
• 15223-25-3 N,N-dibenzylidenebenzene-1,2-diamine 
• 80785-71-3 2,2'-diphenyl-1,1'-bibenzimidazole 
• 53088-00-9 2-phenyl-2,3-dihydro-1H-benzoimidazole 

Relevant academic research and scientific papers

Metal-free oxidative synthesis of benzimidazole compounds by dehydrogenative coupling of diamines and alcohols

We report a novel metal-free synthesis of benzimidazole compounds by dehydrogenative coupling of diamines and alcohols. Using NHPI as a nonmetallic catalyst combined with molecular oxygen or air as the oxidant, this transformation represents a widely applicable protocol to N-heterocycles, such as benzimidazoles, benzothiophenes, benzooxazoles and quinazolines. Flow microreactors operating under optimized conditions enabled this reaction with higher efficiency, and the total residence time was 30 min compared with the batch bubbling reactor (10 h). Moreover, a possible reaction mechanism is proposed according to the control experiments.

A Zirconium Indazole Carboxylate Coordination Polymer as an Efficient Catalyst for Dehydrogenation-Cyclization and Oxidative Coupling Reactions

Rational ligand design is crucial for achieving widespread applications of coordination polymers. The preparation, structural characterisation, and catalytic applications of zirconium (IV) coordination polymer (Zr-IDA), which was derived from 1-(carboxymethyl)-1H-indazole-5-carboxylic acid are reported. The Zr-IDA catalyst contains porous and highly crystalline particles with a quasi-spherical morphology around 100 nm in size, and Zr was coordinated with both O and N as shown by FT-IR and XPS measurements. Importantly, the Zr-IDA catalyst shows great activity, selectivity and stability in the oxidative coupling of benzyl cyanides with tert-butyl hydroperoxide to afford tert-butyl peresters, and the dehydrogenation cyclization of o-phenylenediamines with aromatic alcohols to afford 1,2-disubstituted benzimidazole derivatives. Mechanistic investigations were carried out to study these reactions and the developed catalytic system in more detail.

Three-Way Chemoselectivity Switching through Coupled Equilibria

Controlling the chemoselectivity of reactions operating on complex mixtures, including those found in biological and petrochemical feedstocks or in the primordial soup from which life emerged, is generally challenging. The selectivity of imine oxidation c

Direct synthesis of 2-substituted benzimidazoles: Via dehydrogenative coupling of aromatic-diamine and primary alcohol catalyzed by a Co complex

A Co(ii) complex with a stable structure was designed and synthesized with quinalic acid and Co (OAc)2·4H2O. The single crystal structure of the complex was characterized by X-ray diffraction. A dehydrogenative coupling of aromatic diamines and primary alcohols was developed by using the Co(ii) complex as the catalyst to synthesize 2-substituted benzimidazole. A series of 2-substituted benzimidazoles were obtained with good to excellent yields under mild reaction conditions. In addition, a compound with inhibitory Parkinson's activity was synthesized on a gram-scale by using this method. Finally, the reaction mechanism was proposed and the energy changes in the reaction process were simulated by density functional theory (DFT).

Visible-light-induced condensation cyclization to synthesize benzimidazoles using fluorescein as a photocatalyst

A mild strategy for visible-light-induced synthesis of benzimidazoles was developed using aromatic aldehydes and o-phenylenediamines as substrates. The use of an organic dye, fluorescein, as an innoxious photocatalyst provided a mild and inexpensive catalytic system to synthesize a series of benzimidazoles in moderate to excellent yields. It was originally applied to this system to obtain benzimidazoles. Besides, the catalytic system does not require an additional oxidant or metal which was good for the environment.

Chemoselective aerobic oxidation of 2-amino-N-benzylanilines into N-(2-aminophenyl)imines via a nitroxide-free copper catalysis

Chemoselective oxidative synthesis of N-(2-aminophenyl)imines from 2-amino-N-benzylanilines was accomplished through combined use of O2(air) and copper salt. This transformation was performed at room temperature, and the mild oxidation was efficient and chemoselective without using nitroxyl radicals and ligands.

Cyclization of aromatic aldehydes and phenylenediamines under reduced pressure: A convenient, environmentally friendly, and simple procedure for benzimidazole precursors

The condensation of phenylenediamines with aromatic aldehydes in the presence of catalysts to obtain benzimidazoles under harsh condition is achieved by various reported conditions. The present work demonstrates a convenient, environmentally friendly, and simple procedure to obtain benzimidazoles through the cyclization between phenylenediamines and aromatic aldehydes under reduced pressure. By simply adding aromatic aldehydes to diaminobenzene derivatives and allowing the stoichiometric reaction at room temperature under reduced pressure at 66.6 Pa, the dehydrogenation leads to benzimidazoles with the yield as high as 80–90%. In addition, the purging of H2 gas to benzimidazoles results in the hydrogenation of imidazole to obtain the intermediate benzimidazolidine form. This confirms how the cyclization relies on the reduced pressure. This synthesis pathway not only gives the aromatic aldehydes with high yield under the mild condition but also the selection of benzaldehydes with reactive functional groups leads to the precursors for other chemical modifications and polymerizations.

I2-Mediated Intramolecular C-H Amidation for the Synthesis of N-Substituted Benzimidazoles

A practical intramolecular C-H amidation methodology has been developed using molecular iodine under basic conditions. The required imine substrates were readily obtained by condensation of simple o-phenylenediamine derivatives and aldehydes. The transition-metal-free cyclization reaction described here works well with crude imines and allows for the sequential synthesis of N-protected benzimidazoles without purification of the less stable condensation intermediates. This operationally simple synthetic approach is broadly applicable to a variety of aromatic, aliphatic, and cinnamic aldehydes to produce diverse 1,2-disubstituted benzimidazole derivatives in an efficient and scalable fashion.

Iron(II) bromide-catalyzed oxidative coupling of benzylamines with ortho-substituted anilines: Synthesis of 1,3-benzazoles

An iron(II) bromide-catalyzed oxidative coupling of benzylamines with 2-amino/hydroxy/mercapto-anilines has been developed, allowing the synthesis of a diversity of substituted 1,3-benzazoles in good to excellent yields. This transformation is compatible with a wide range of functional groups. The method is practical, economical and employs molecular oxygen as an oxidant.

Significant facilitation of metal-free aerobic oxidative cyclization of imines with water in synthesis of benzimidazoles

A simple, convenient, and environmentally benign protocol for the synthesis of benzimidazoles from ortho-phenylenediamines and aldehydes via aerobic oxidation was developed in wet organic solvents. Notably, water significantly accelerated this transformation, which allowed us to achieve this important transformation without the assistance of any metal catalysts and other co-oxidants. Mechanistic studies suggested that water acts as the nucleophilic catalyst for this transformation by the conversion of disfavored 5-endo-trig cyclization of imines to favored 5-exo-tet cyclization via tetrahedral intermediates and the subsequent aerobic oxidation of the resulting benzimidazolines affords benzimidazoles.