- Efficiency phosphorescent OLEDs with a low roll-off based on a hetero-triplet iridium complex
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In order to explore the triplet-triplet annihilation in cyclometalated iridium complexes, a hetero-triplet iridium complex [Ir(ppy)2pbi] employing two 2-phenylpyridine (Hppy) ligands and one 1,2-diphenyl-1H-benzo[d]-imidazole (Hpbi) ligand with
- Han, Liangliang,Zhang, Dongyu,Wang, Jun,Lan, Zhenggang,Yang, Renqiang
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Read Online
- Enhancing the luminescence properties and stability of cationic iridium(iii) complexes based on phenylbenzoimidazole ligand: A combined experimental and theoretical study
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Herein we designed and synthesized a series of cationic iridium(iii) complexes with a phenylbenzoimidazole-based cyclometalated ligand, containing different numbers of carbazole moieties from zero to three (complexes 1-4). The photophysical and electroche
- Shan, Guo-Gang,Li, Hai-Bin,Sun, Hai-Zhu,Cao, Hong-Tao,Zhu, Dong-Xia,Su, Zhong-Min
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Read Online
- Access to 2-Arylquinazolin-4(3H)-ones through Intramolecular Oxidative C(sp3)?H/N?H Cross-Coupling Mediated by I2/DMSO
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A novel approach for the synthesis of 2-arylquinazolin-4(3H)-ones was developed. A series of title compounds were obtained with good functional group tolerance and good yields by I2/DMSO-mediated intramolecular oxidative cross-coupling of 2-(benzylamino)benzamides to form C=N double bonds. This method was applicable for gram-scale synthesis. A proposed reaction pathway based on some control experiments was also provided.
- Wen, Simiaomiao,Du, Yifan,Liu, Yiwen,Cui, Xiaofeng,Liu, Qixing,Zhou, Haifeng
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- Method for preparing 2 -phenyl quinazolinone compound
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The invention relates to a preparation method of 2 -phenyl quinazolinone compounds, in particular to II. To the method, 2 - (benzylamino) benzamide compound (I) is used as a raw material for reaction of the experiment model, a simple substance iodine cata
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Paragraph 0063-0065
(2021/10/30)
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- Ionic-Liquid-Catalyzed Synthesis of Imines, Benzimidazoles, Benzothiazoles, Quinoxalines and Quinolines through C?N, C?S, and C?C Bond Formation
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We report the tetramethyl ammonium hydroxide catalyzed oxidative coupling of amines and alcohols for the synthesis of imines under metal-free conditions by utilizing oxygen from air as the terminal oxidant. Under the same conditions, with ortho-phenylene diamines and 2-aminobenzenethiols the corresponding benzimidazoles and benzothiazoles were obtained. Quinoxalines were obtained from ortho-phenylene diamines and 1-phenylethane-1,2-diol, the conditions were then extended to the synthesis of quinoline building blocks by reaction of 2-amino benzyl alcohols either with 1-phenylethan-1-ol or acetophenone derivatives. The formation of C?N, C?S and C?C bonds was achieved under metal-free conditions. A broad range of amines (aromatic, aliphatic, cyclic and heteroaromatic) as well as benzylic alcohols including heteroaryl alcohols reacted smoothly and provided the desired products. The mild reaction conditions, commercially available catalyst, metal-free, good functional-group tolerance, broad range of products (imines, benzimidazoles, benzothiazoles, quinoxalines and quinolines) and applicability at gram scale reactions are the advantages of the present strategy.
- Adimurthy, Subbarayappa,Badhani, Gaurav,Joshi, Abhisek
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p. 6705 - 6716
(2021/12/31)
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- Transition-Metal-Free Synthesis of 1,2-diphenyl-1H-benzo[d] Imidazole Derivatives from N-phenylbenzimidamides and Cyclohexanones
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A transition-metal-free strategy for the formation of 1,2-diphenyl-1H-benzo[d] imidazoles from N-phenylbenzimidamides and cyclohexanones is introduced. This is the first report on the direct synthesis of 1,2-diphenyl-1H-benzo[d] imidazoles from cyclohexanones and N-phenylbenzimidamides via iodine- promoted oxidative cyclization. Non-aromatic cyclohexanones were smoothly dehydrogenated, and acted as an aryl source using oxygen as a green oxidant. The catalytic use of iodine makes this method quite simple, more economical and convenient. Under optimized conditions, various substituted 1,2-diphenyl-1H-benzo[d] imidazoles were smoothly reacted, and the desired substituted imidazoles were generated with moderate to excellent yields. (Figure presented.).
- Lu, Guoqiang,Luo, Nan,Hu, Fangpeng,Ban, Zihui,Zhan, Zhenzhen,Huang, Guo-Sheng
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supporting information
p. 487 - 492
(2019/12/12)
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- SYNTHESIS METHOD OF IMIDAZOLES
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PROBLEM TO BE SOLVED: To provide benzimidazoles with small number of processes at high selectivity and high purity. SOLUTION: A synthesis method of benzimidazoles synthesizes at least one of an imidazole derivative and a carboxy imidazole derivative by reacting a diamine derivative and at least one of a dicarboxylic acid derivative and a dicarboxylic acid anhydride derivative in subcritical water or in supercritical water. For example, in subcritical water or in supercritical water, by reacting o-phenylene diamine and at least one of phthalic acid and phthalic anhydride, 2-phenylbenzimidazole and 2-o-benzimidazole benzoate are synthesized. SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
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Paragraph 0110; 0111
(2019/05/15)
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- Sulfur-Catalyzed Oxidative Coupling of Dibenzyl Disulfides with Amines: Access to Thioamides and Aza Heterocycles
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In the presence of catalytic amounts of elemental sulfur, dibenzyl disulfide/DMSO was found to be an excellent thiobenzoylating agent of amines to provide a wide range of thioamides. The reaction becomes autocatalytic when anilines substituted by an o-cyclizable group were used as nucleophile, leading to the corresponding 2-aryl aza heterocycles. (Figure presented.).
- Nguyen, Thanh Binh,Nguyen, Le Phuong Anh,Nguyen, Thi Thu Tram
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supporting information
p. 1787 - 1791
(2019/02/26)
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- Enhanced Catalytic Properties of Molybdenum Promoted Mesoporous Cobalt Oxide: Structure-Surface-Dependent Activity for Selective Synthesis of 2-Substituted Benzimidazoles
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High-valent molybdenum ions were substituted into the cobalt oxide lattice through a one step, sol-gel method and investigated for selective synthesis of 2-substituted benzimidazoles. Catalyst synthesis involves surfactant assisted soft templating inverse micelle method, which forms mesopores by interconnected intraparticle voids. Substitutional doping of Mo6+ resulted in materials with modified structural, morphological, surface, and redox properties. The catalytic activity increased with Mo concentration until an optimum amount (3 % Mo incorporation). Modified material shows lattice expansion, increased surface oxygen vacancies, and high surface area, which are responsible for the higher catalytic activity in selective benzimidazole synthesis reaction. A strong correlation between surface properties of the catalyst and the product selectivity was observed and plausible mechanistic and kinetic data are proposed and collected, respectively.
- Weerakkody, Chandima,Rathnayake, Dinithi,He, Junkai,Dutta, Biswanath,Kerns, Peter,Achola, Laura,Suib, Steven L.
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p. 528 - 537
(2018/09/25)
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- Nickel-Catalyzed Heteroarenes Cross Coupling via Tandem C-H/C-O Activation
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Inert aryl methyl ethers as coupling components via C-O activation have been established with a Ni catalyst for C-H activation of heteroarene. The key to simultaneous C-H/C-O bond activation is the use of sterically demanding o-tolylMgBr. The protocol is effective for a wide scope of substrates including naphthyl methyl ethers, anisoles, and a variety of other heteroarene derivatives. Detailed mechanistic studies indicated that the C-O cleavage is assisted via synergistic effect of nickel and Grignard reagent in this C-H/C-O reaction, which is supported by DFT calculation. At this stage, single-electron transfer can be ruled out as a main operative process for this tandem strategy.
- Wang, Ting-Hsuan,Ambre, Ram,Wang, Qing,Lee, Wei-Chih,Wang, Pen-Cheng,Liu, Yuhua,Zhao, Lili,Ong, Tiow-Gan
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p. 11368 - 11376
(2018/11/23)
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- The synthesis of benzimidazoles via a recycled palladium catalysed hydrogen transfer under mild conditions
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An efficient synthesis of benzimidazoles was developed by virtue of a recycled palladium catalyzed hydrogen transfer. The reaction can be carried out smoothly under mild conditions to give rise to a variety of benzimidazoles with good to excellent yields. The palladium catalyst could be recovered easily and reused six times with great catalytic activity.
- Guan, Qianqian,Sun, Qi,Wen, Lixian,Zha, Zhenggen,Yang, Yu,Wang, Zhiyong
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p. 2088 - 2096
(2018/03/27)
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- CIRCULATION CONTINUOUS PROCESSING METHOD AND DEVICE CONTAINING REACTION, EXTRACTION, AND ISOLATION FOR SYNTHETIC REACTION IN HIGH TEMPERATURE AND HIGH PRESSURE WATER
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PROBLEM TO BE SOLVED: To efficiently obtain a product having high purity by making it possible to continuously perform a reaction step, an extraction step and an isolation step in a flow method by suppressing precipitation of a solid phase during reduced pressure in a production method of an organic compound with high temperature and high pressure water as a reaction medium. SOLUTION: A circulation continuous processing method for synthetic reaction in high temperature and high pressure water includes: (I) a reacting step in which high temperature and high pressure water having a temperature of 100°C or higher and 500°C or lower and a pressure of exceeding normal pressure and 60 MPa or lower and a reaction substrate are reacted to generate a reaction product; (II) an extracting step in which an organic solvent that dissolves the reaction product is mixed with a mixed liquid that in the temperature and pressure range after the reaction to extract the reaction product in the organic solvent, and ; (III) a separating step in which the mixed liquid after the extracting is depressurized to form a mixed liquid in which an organic solvent solution and an aqueous solution are separated and dispersed with each other, followed by membrane separating the mixed solution to obtain the organic solvent solution and aqueous solution, these steps are continuously performed. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0042; 0043; 0044; 0050; 0051; 0054
(2018/09/25)
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- Novel bluish green benzimidazole-based iridium(III) complexes for highly efficient phosphorescent organic light-emitting diodes
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Three multifluorinated benzimidazole-based iridium [Ir(iii)] complexes abbreviated as 1F-Ir, 2F-Ir, and 3F-Ir were designed and synthesized. Their photoluminescent, thermal, and electrochemical properties were investigated in detail. These Ir(iii) complex
- Zhao, Jin-Hui,Hu, Yong-Xu,Dong, Yan,Xia, Xin,Chi, Hai-Jun,Xiao, Guo-Yong,Li, Xiao,Zhang, Dong-Yu
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p. 1973 - 1979
(2017/03/09)
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- I2-Mediated Intramolecular C-H Amidation for the Synthesis of N-Substituted Benzimidazoles
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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.
- Hu, Zhiyuan,Zhao, Ting,Wang, Manman,Wu, Jie,Yu, Wenquan,Chang, Junbiao
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p. 3152 - 3158
(2017/03/23)
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- METHOD FOR THE SYNTHESIS OF BENZAZOLE
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PROBLEM TO BE SOLVED: To obtain a benzazole in a short reaction time with high yields. SOLUTION: A method for the synthesis of a benzazole includes a chemical reaction represented by the chemical reaction formula (1) to occur in subcritical water or supercritical water (X is NR6, O, or S. Y is H, OR7, halogen, or NR8R9. R1 to R9 are a C1-C20 aliphatic or aromatic substituent which may have O, N, S, B, Si, halogen, or P (two or more substituents of R1 to R6 may be coupled together, R8 and R9 may be coupled together, and two or more substituents of R1 to R9 may be the same) or H). SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
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Paragraph 0021; 0022; 0024; 0025
(2017/09/19)
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- A one-pot synthesis of 1, 2 - diaryl benzimidazole and its derivatives
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The invention discloses a one-pot synthesis method of 1,2-diarylbenzimidazole and derivatives thereof and belongs to the technical field of chemical preparation. The synthesis method comprises the following steps: adding o-phenylenediamine, benzaldehyde and halogeno benzene which are raw materials into a pressure bottle of 50mL according to the ratio of 1:1.2:1, adding a metal catalyst, an alkali, a ligand and an organic solvent, stirring at the temperature of 110-130 DEG C for 16-24 hours to synthesize 1,2-diarylbenzimidazole and derivatives thereof, cooling, filtering, extracting, distilling at a reduced pressure, and carrying out chromatographic separation by using a column to obtain purified products. The one-pot synthesis method disclosed by the invention has the advantages of mild reaction condition, simple post-treatment, high product selectivity and wide substrate expansion range, and in addition, the one-pot synthesis method can be used for constructing polyaryl imidazole compounds and derivatives easily and efficiently.
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Paragraph 0022; 0023; 0024; 0025; 0026; 0027; 0028-0098
(2017/08/25)
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- Method for preparation of benzimidazole derivatives
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The invention relates to a method for preparation of benzimidazole derivatives. The specific method comprises the steps that nitridone compounds undergo a cyclic addition reaction in a catalysis condition of transition metal trivalent cobalt to prepare the benzimidazole derivatives. In the method, the reactant nitridone can be prepared from a cheap and easy available starting raw material, moreover, the reaction is simple to operate, the conditions are mild, and a substrate has wide applicable range.
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Paragraph 0016-0018
(2017/07/21)
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- Oxidative Synthesis of Benzimidazoles, Quinoxalines, and Benzoxazoles from Primary Amines by ortho-Quinone Catalysis
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The bioinspired ortho-quinone catalysts have been applied to heterocycles synthesis. Without any metal cocatalysts, a sole ortho-quinone catalyst enables the oxidative synthesis of benzimidazoles, quinoxalines and benzoxazoles from primary amines in high yields under mild conditions with oxygen as the terminal oxidant.
- Zhang, Ruipu,Qin, Yan,Zhang, Long,Luo, Sanzhong
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supporting information
p. 5629 - 5632
(2017/10/25)
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- Simple molecular structure design of iridium(III) complexes: Achieving highly efficient non-doped devices with low efficiency roll-off
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To construct efficient emitters suitable for non-doped devices and deeply understand the relationship between structures and performances, we designed and synthesized two heteroleptic iridium(III) complexes based on 1,2-diphenyl-1H-benzoimidazole (PBI) li
- Wen, Li-Li,Yu, Jing,Sun, Hai-Zhu,Shan, Guo-Gang,Zhao, Kai-Yue,Xie, Wen-Fa,Su, Zhong-Min
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p. 142 - 150
(2016/06/01)
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- Phosphorescent material
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Heteroleptic compounds containing phenylpyridine and phenylbenzimidazole are provided. The compounds may be used in organic light emitting devices, particularly as emissive dopants in the emissive layer of such devices.
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Paragraph 0094; 0095
(2017/02/24)
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- A facile color-tuning strategy for constructing a library of Ir(III) complexes with fine-tuned phosphorescence from bluish green to red using a synergetic substituent effect of -OCH3 and -CN at only the C-ring of C∧N ligand
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By simply grafting a -CN group and/or a -OCH3 group onto the meta- and/or para-site of the C-ring, a series of Ir(iii) complexes bearing a similar molecular platform of bis(1,2-diphenyl-1H-benzimidazolato-N,C2′)iridium(iii)(acetylacetonate), but showing fine-tuned phosphorescence covering nearly the whole window of the visible spectrum with a wide color-tuning range of 109 nm was acquired. With the help of DFT calculations, it was revealed that if the C-related arene moiety of the C∧N ligand (C-ring) contributes substantially to both the HOMO and LUMO of an Ir(iii) complex, the concurrent introduction of an electron-donating -OCH3 and an electron-withdrawing -CN groups on the C-ring at the meta- and para-sites relative to the Ir atom may lead to a favorable synergetic substituent effect on the color-tuning direction. This may represent a facile yet effective molecular design strategy for Ir(iii) complexes with a desirous emission color. A bluish green organic light-emitting diode (OLED) based on one of the objective complexes displayed a maximum current efficiency of 62.1 cd A-1, an external quantum efficiency of 19.8%, and a brightness of 48-040 cd m-2, implying that high-performance red and blue OLED phosphors as well as libraries of Ir(iii) complexes bearing similar molecular platforms may be developed through this -OCH3 and -CN synergetic substitution strategy.
- Jiao, Yan,Li, Ming,Wang, Ning,Lu, Tao,Zhou, Liang,Huang, Yan,Lu, Zhiyun,Luo, Daibing,Pu, Xuemei
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supporting information
p. 4269 - 4277
(2016/06/01)
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- Rapid production of benzazole derivatives by a high-pressure and high-temperature water microflow chemical process
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A high-pressure and high-temperature (HPHT) water microflow chemical process was utilized for the synthesis of benzazole derivatives. The current approach enables the extremely rapid production of various 2-arylbenzazoles including benzimidazoles, benzoxazoles, and benzthiazole in excellent yields.
- Nagao,Ishizaka,Kawanami
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supporting information
p. 3494 - 3498
(2016/07/06)
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- Development of a supramolecular ensemble of an AIEE active hexaphenylbenzene derivative and Ag@Cu2O core-shell NPs: An efficient photocatalytic system for C-H activation
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A supramolecular ensemble having Ag@Cu2O core-shell nanoparticles stabilized by aggregates of a hexaphenylbenzene derivative has been developed which exhibits excellent photocatalytic efficiency in reactions involving preparation of imidazole and benzimidazole derivatives via C-H activation.
- Chopra, Radhika,Kumar, Manoj,Bhalla, Vandana
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supporting information
p. 10179 - 10182
(2016/08/18)
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- CuO nanoparticle-catalyzed diaminations for synthesis of benzimidazole derivatives
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Copper oxide nanoparticles have been applied as an efficient catalyst for the formation of C–N bonds. They can catalyze diaminations for the regiospecific synthesis of 1,2-disubstituted benzimidazoles from 1,2-dihaloarenes and N-arylamidines. The best per
- Yu, Dan,You, Qing,Zhang, Xinming,Tao, Guide,Zhang, Wu
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p. 695 - 698
(2016/07/19)
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- Electrochemical Synthesis of Benzazoles from Alcohols and o-Substituted Anilines with a Catalytic Amount of CoII Salt
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An electrochemical synthesis of benzazoles directly from alcohols and o-substituted anilines has been developed. The reaction conditions have been optimized by varying the composition of the electrolyte and the metal salt used as catalyst. The cyclization proceeds smoothly with a catalytic amount of a cobalt salt under air at room temperature to afford 2-substituted benzimidazoles, benzothiazoles, and benzoxazoles in good to excellent yields with a wide substrate scope.
- Lai, Yin-Long,Ye, Jian-Shan,Huang, Jing-Mei
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p. 5425 - 5429
(2016/04/09)
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- Catalytic Oxidative Coupling of Primary Amines under Air: A Flexible Route to Benzimidazole Derivatives
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Benzimidazoles are of fundamental importance in chemistry and biology, and the development of efficient, environmentally benign methods for their preparation remains a key challenge for organic chemists. In a biomimetic approach inspired by copper amine oxidases, we disclose herein the scope and factors influencing the success of the cooperative action of CuBr2 as electron-transfer mediator and a topaquinone-like substrate-selective catalyst in the oxidative cyclocondensation of primary amines with o-aminoanilines. This one-pot atom-economic multistep process, which works under green conditions with ambient air as the terminal oxidant, low loadings of catalyst, and equimolar amounts of commercially available amine substrates, is particularly suitable for the preparation of 1,2-disubstituted benzimidazoles. Furthermore, it allows the functionalization of nonactivated primary aliphatic amines, which are known to be challenging substrates for non-enzymatic catalytic aerobic systems.
- Nguyen, Khac Minh Huy,Largeron, Martine
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p. 1025 - 1032
(2016/03/01)
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- Significant facilitation of metal-free aerobic oxidative cyclization of imines with water in synthesis of benzimidazoles
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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.
- Lee, Ye-Sol,Cho, Yeon-Ho,Lee, Seungjae,Bin, Jong-Kwan,Yang, Joonghwan,Chae, Geesung,Cheon, Cheol-Hong
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supporting information
p. 532 - 538
(2015/02/05)
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- Sulfate Radical Anion (SO4?-) Mediated C(sp3)-H Nitrogenation/Oxygenation in N-Aryl Benzylic Amines Expanded the Scope for the Synthesis of Benzamidine/Oxazine Heterocycles
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A transition-metal-free, K2S2O8-mediated intramolecular oxidative nitrogenation/oxygenation of C(sp3)-H in N-aryl benzylic amines followed by oxidation at the benzylic center has been developed for the synthesis of benzamidine/benzoxazine heterocycles, providing an expedient access to quinazolin-4(3H)-ones, N-aryl-2-arylbenzimidazoles, and 4H-3,1-benzoxazin-4-ones. A considerable amount of work dealing with the mechanistic study to understand the crucial intramolecular cyclization step largely favors an iminium ion as the key intermediate.
- Laha, Joydev K.,Tummalapalli, K. S. Satyanarayana,Nair, Akshay,Patel, Nidhi
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p. 11351 - 11359
(2015/12/01)
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- C-H arylation and alkenylation of imidazoles by nickel catalysis: Solvent-accelerated imidazole C-H activation
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The first nickel-catalyzed C-H arylations and alkenylations of imidazoles with phenol and enol derivatives are described. Under the influence of Ni(OTf)2/dcype/K3PO4 (dcype: 1,2-bis(dicyclohexylphosphino)ethane) in t-amyl alcohol, imidazoles can undergo C-H arylation with phenol derivatives. The C-H arylation of imidazoles with chloroarenes as well as that of thiazoles and oxazoles with phenol derivatives can also be achieved with this catalytic system. By changing the ligand to dcypt (3,4-bis(dicyclohexylphosphino)thiophene), enol derivatives could also be employed as coupling partners achieving the C-H alkenylation of imidazoles as well as thiazoles and oxazoles. Thus, a range of C2-arylated and alkenylated azoles can be synthesized using this newly developed nickel-based catalytic system. The key to the success of the C-H coupling of imidazoles is the use of a tertiary alcohol as solvent. This also allows the use of an air-stable nickel(ii) salt as the catalyst precursor.
- Muto, Kei,Hatakeyama, Taito,Yamaguchi, Junichiro,Itami, Kenichiro
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p. 6792 - 6798
(2015/11/24)
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- Iron(III) Chloride-Catalyzed Decarboxylative-Deaminative Functionalization of Phenylglycine: A Tandem Synthesis of Quinazolinones and Benzimidazoles
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The first iron(III) chloride-catalyzed decarboxylative-deaminative functionalization of phenylglycine with o-substituted nitroarenes was achieved for the synthesis of 4(3H)-quinazolinones and benzimidazoles. The reaction of 2-nitrobenzonitrile/2-nitro-N,N-diphenylamine with phenylglycine at 120 C in the presence of potassium carbonate as a base in toluene generated the products in 45-87% yields. Various functional groups like nitro, fluoride, chloride and trifluoromethyl were well tolerated under the present reaction conditions. In this tandem approach, involvement of transfer hydrogenation of the nitro functionality with in situ generated ammonia, imination, nitrile hydration to amide and oxidative cyclization sequences have been established. The process avoids the use of an external hydrogen source, costly catalysts as well as the isolation of amine and amide intermediates.
- Kumar, Manoranjan,Richa,Sharma, Sushila,Bhatt, Vinod,Kumar, Neeraj
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supporting information
p. 2862 - 2868
(2015/09/28)
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- A Bioinspired Catalytic Aerobic Oxidative C-H Functionalization of Primary Aliphatic Amines: Synthesis of 1,2-Disubstituted Benzimidazoles
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Aerobic oxidative C-H functionalization of primary aliphatic amines has been accomplished with a biomimetic cooperative catalytic system to furnish 1,2-disubstituted benzimidazoles that play an important role as drug discovery targets. This one-pot atom-economical multistep process, which proceeds under mild conditions, with ambient air and equimolar amounts of each coupling partner, constitutes a convenient environmentally friendly strategy to functionalize non-activated aliphatic amines that remain challenging substrates for non-enzymatic catalytic aerobic systems.
- Nguyen, Khac Minh Huy,Largeron, Martine
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supporting information
p. 12606 - 12610
(2015/09/01)
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- Ring contraction of 1,3-diphenylbenzo[1,2,4]triazinyl radicals to 1,2-diphenylbenzimidazoles
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Reductive ring contraction of 1,3-diphenyl-1,4-dihydrobenzo[e][1,2,4] triazin-4-yls (Blatter's radicals) using zinc powder (2 equiv.) in acetic acid heated to ca. 118 °C gives 1,2-diphenylbenzimidazoles in high yield. 1,3-Diphenylbenzo[e][1,2,4]triazin-7(
- Berezin, Andrey A.,Koutentis, Panayiotis A.
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p. 1641 - 1648
(2014/03/21)
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- Solvent/oxidant-switchable synthesis of multisubstituted quinazolines and benzimidazoles via metal-free selective oxidative annulation of arylamidines
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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.
- Lin, Jian-Ping,Zhang, Feng-Hua,Long, Ya-Qiu
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p. 2822 - 2825
(2014/06/23)
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- Tuning the photophysical and electrochemical properties of iridium(III) 2-aryl-1-phenylbenzimidazole complexes
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A series of heteroleptic bis-cyclometalated iridium(III) complexes, [Ir(cpbi)2(H2dcbpy)][PF6] (1), [Ir(pbi) 2(H2dcbpy)][PF6] (2), and [Ir(mpbi) 2(H2dcbpy)][PF6] (3), where pbi = 1,2-diphenylbenzimidazole, cpbi = 2-(4-chlorophenyl)-1-phenylbenzimidazole, mpbi = 2-(3,4-dimethoxyphenyl)-1-phenylbenzimidazole, and H2dcbpy = 2,2′-bipyridine-4,4′-dicarboxylic acid has been synthesized and characterized by elemental analysis, 1H, 31P NMR, and high resolution mass-spectra. Molecular structure of complex 3 has been determined from single-crystal X-ray analysis. The complexes exhibit absorption up to 550 nm with molar absorptivities of 2500 M-1 cm-1. They have strong luminescence in broad yellow-to-red region in solutions at room temperature. While chloro-substituent (complex 1) causes a little hypsochromic shift of the absorption maxima compared to unsubstituted 2, introduction of two methoxy-groups (complex 3) gives rise to a bathochromic shift of about 100 nm. Alternating current voltammetry studies of the complexes indicates reversible oxidation and reduction potentials. Calculated excited state oxidation potentials for 1-3 are negative enough to efficiently inject electrons into the conduction band of TiO2 (EF). 2014 Elsevier B.V. All rights reserved.
- Bezzubov, Stanislav I.,Doljenko, Vladimir D.,Troyanov, Sergey I.,Kiselev, Yuri M.
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- Transition-metal-free synthesis of benzimidazoles mediated by KOH/DMSO
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Benzimidazoles are prepared by intramolecular N-arylations of amidines mediated by potassium hydroxide in DMSO at 120 °C. In this manner, diversely substituted products have been obtained in moderate to very good yields.
- Baars, Hannah,Beyer, Astrid,Kohlhepp, Stefanie V.,Bolm, Carsten
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p. 536 - 539
(2014/04/03)
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- Benzoyl methyl phosphates as efficient reagents in the one-pot tandem approach for the synthesis of 2-phenylbenzimidazoles in water
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A novel and efficient method for the environmentally benign, catalyst- and auxiliary-free synthesis of 2-phenylbenzimidazoles in water is developed. Benzoyl methyl phosphates play important roles as biomimetic acylating agents for the one-pot tandem approach without additional catalysts.
- Hikawa, Hidemasa,Imani, Maki,Suzuki, Hideharu,Yokoyama, Yuusaku,Azumaya, Isao
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p. 3768 - 3773
(2014/01/06)
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- Synthesis of some fluorescent benzimidazole derivatives using cobalt(ii) hydroxide as highly efficient catalyst-spectral and physico-chemical studies and ESIPT process
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Some fluorescent benzimidazole derivatives have been designed and synthesized using cobalt(ii) hydroxide as highly efficient catalyst. Synthesized compounds have been characterized by 1H and 13C-NMR and mass spectral analysis. The so
- Jayabharathi,Thanikachalam,Jayamoorthy
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p. 1761 - 1773
(2013/10/08)
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- "All-water" one-pot diverse synthesis of 1,2-disubstituted benzimidazoles: Hydrogen bond driven 'synergistic electrophile-nucleophile dual activation' by water
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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."
- Kommi, Damodara N.,Jadhavar, Pradeep S.,Kumar, Dinesh,Chakraborti, Asit K.
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p. 798 - 810
(2013/04/24)
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- Optical properties of 1,2-diaryl benzimidazole derivatives - A combined experimental and theoretical studies
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Some novel 1,2-diaryl benzimidazole derivatives have been designed, synthesized and characterized by mass, 1H, 13C-NMR spectral studies and single crystal XRD. The charge distribution has been calculated from the atomic charges by no
- Jayabharathi,Thanikachalam,Jayamoorthy
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supporting information
p. 74 - 78
(2013/11/06)
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- One-pot sequential synthesis of 1,2-disubstituted benzimidazoles under metal-free conditions
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An easy and inexpensive method has been developed to access 1,2-disubstituted benzimidazoles following a one-pot sequential coupling/reduction/cyclization process under metal-free neutral conditions.
- Roy, Priyabrata,Pramanik, Animesh
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supporting information
p. 5243 - 5245
(2013/09/02)
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- Conventional and microwave-assisted synthesis of benzimidazole derivatives and their in vitro inhibition of human cyclooxygenase
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A large series of 1,2-diaryl-benzimidazole and 2-aryl-1H-benzimidazole derivatives were synthesized with slight differences using both microwave irradiation and conventional heating methods. Usually higher yields and time reactions reduction were obtained
- Secci, Daniela,Bolasco, Adriana,D'Ascenzio, Melissa,Della Sala, Flavio,Yanez, Matilde,Carradori, Simone
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p. 1187 - 1195
(2013/01/15)
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- One-pot synthesis of imidazole derivatives under solvent-free condition
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A convenient and environment-friendly solvent-free procedure has been developed for one-pot synthesis of imidazole derivatives. On comparing the new method with the classical reaction condition, this new synthetic method shows many advantages such as high
- Zhang, Qiu-Gen,Xie, Yu,Hu, Jin-Gang,Liu, Jin-Mei,Wang, Juan,Zhong, Rong,Gao, Yun-Hua
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scheme or table
p. 4611 - 4613
(2012/08/28)
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- A highly selective sulfur-free iridium(iii)-complex-based phosphorescent chemidosimeter for detection of mercury(ii) ions
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A neutral phosphorescent coordination compound bearing a benzimidazole ligand, Ir(pbi)2(acac) (Hpbi = 1,2-diphenyl-1H-benzo[d]imidazole; Hacac = acetylacetone), is demonstrated to be the first example of a sulfur-free iridium complex for the de
- Zeng, Hui,Yu, Fang,Dai, Jun,Sun, Huiqin,Lu, Zhiyun,Li, Ming,Jiang, Qing,Huang, Yan
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supporting information; experimental part
p. 4878 - 4883
(2012/06/04)
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- Copper-catalyzed CuAAC/intramolecular C-H arylation sequence: Synthesis of annulated 1,2,3-triazoles
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Step-economical syntheses of annulated 1,2,3-triazoles were accomplished through copper-catalyzed intramolecular direct arylations in sustainable one-pot reactions. Thus, catalyzed cascade reactions involving [3 + 2]-azide-alkyne cycloadditions (CuAAC) and C-H bond functionalizations provided direct access to fully substituted 1,2,3-triazoles with excellent chemo- and regioselectivities. Likewise, the optimized catalytic system proved applicable to the direct preparation of 1,2-diarylated azoles through a one-pot C-H/N-H arylation reaction.
- Jeyachandran, Rajkumar,Potukuchi, Harish Kumar,Ackermann, Lutz
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p. 1771 - 1777,7
(2020/09/16)
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- Copper-catalyzed synthesis of 1,2-disubstituted benzimidazoles from imidoyl chlorides
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A strategy for the synthesis of 1,2-disubstituted benzimidazoles has been developed and a variety of 1,2-disubstituted benzimidazoles were obtained from imidoyl chlorides and o-haloanilines via copper(I)-catalyzed reaction in moderate yields.
- Yu, Hui,Zhang, Mei Shu,Cui, Li Ren
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experimental part
p. 573 - 575
(2012/07/14)
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- Copper-catalyzed intramolecular C-N bond formation: A straightforward synthesis of benzimidazole derivatives in water
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A straightforward, efficient, and more sustainable copper-catalyzed method has been developed for intramolecular N-arylation providing the benzimidazole ring system. With Cu2O (5 mol %) as the catalyst, DMEDA (10 mol %) as the ligand, and K2CO3 as the base, this protocol was applied to synthesize a small library of benzimidazoles in high yields. Remarkably, the reaction was exclusively carried out in water, rendering the methodology highly valuable from both environmental and economical points of view.
- Peng, Jinsong,Ye, Min,Zong, Cuijuan,Hu, Fangyun,Feng, Lingtong,Wang, Xiaoyan,Wang, Yufeng,Chen, Chunxia
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supporting information; experimental part
p. 716 - 719
(2011/03/20)
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- A direct, regioselective palladium-catalyzed synthesis of N-substituted benzimidazoles and imidazopyridines
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Unsymmetric, N-substituted benzimidazoles and imidazopyridines can be prepared directly from 2-halonitroarenes and amides through Pd(TFA) 2/(R)-BINAP-catalyzed cross-coupling and subsequent reductive aminocyclization. This sequence can be conducted by a one-pot procedure. The method is versatile and allows the straightforward, regioselective preparation of these important nitrogen heterocycles. Unsymmetrical, N-substituted benzimidazoles can be prepared directly from 2-halonitroarenes and amides through Pd(TFA)2/(R)-BINAP-catalyzed cross-coupling and subsequent reductive aminocyclization.This sequence can be conducted by a one-pot procedure. The method is versatile and allows the straightforward, regioselective preparation of these important nitrogen heterocycles. Copyright
- Alonso, Jorge,Halland, Nis,Nazare, Marc,R'Kyek, Omar,Urmann, Matthias,Lindenschmidt, Andreas
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supporting information; experimental part
p. 234 - 237
(2011/03/20)
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- Regiospecific synthesis of 1, 2-disubstituted (hetero)aryl fused imidazoles with tunable fluorescent emission
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A palladium-catalyzed two or fourfold amination was established that allows regiospecific synthesis of a diversity-oriented library of 1, 2 disubstituted (hetero)aryl fused imidazoles, and provides an exceptional tool for the discovery of fluorescent scaf
- Zhao, Dongbing,Hu, Junyi,Wu, Ningjie,Huang, Xiaolei,Qin, Xurong,Lan, Jingbo,You, Jingsong
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supporting information; experimental part
p. 6516 - 6519
(2012/02/02)
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- An easy one-step photocatalytic synthesis of 1-aryl-2-alkylbenzimidazoles by platinum loaded TiO2 nanoparticles under UV and solar light
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One-pot synthesis of disubstituted benzimidazoles from N-substituted 2-nitroanilines or 1,2-diamines with 3-12 nm-sized platinum particles loaded on the TiO2 using solar and UV-A light is described. 1-Aryl-2-alkylbenzimidazoles from 2-nitrodiphenylamines are formed by combined redox photocatalytic reaction, condensation and catalytic dehydrogenation on Pt-TiO2. In case of diamines, this reaction is proceeded by Pt-TiO2 assisted photocatalytic oxidation of an alcohol and a catalytic dehydrogenation of the intermediate on the surface of platinum nanoparticles. In both cases product formation was achieved by tandem photocatalytic and catalytic reactions on Pt-TiO2.
- Selvam,Swaminathan
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experimental part
p. 3386 - 3392
(2011/06/28)
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- Cobalt-catalyzed intramolecular C-N and C-O cross-coupling reactions: Synthesis of benzimidazoles and benzoxazoles
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Cobalt(ii)-complex catalyzes efficiently the intramolecular C-N and C-O cross-couplings of Z-N′-(2-halophenyl)-N-phenylamidines and N-(2-bromophenyl)benzamides to afford the corresponding substituted benzimidazoles and benzoxazoles in the presence of K2CO3 at moderate temperature. The protocol is general, air stable and affords the products selectively in moderate to high yield.
- Saha, Prasenjit,Ali, Md Ashif,Ghosh, Pokhraj,Punniyamurthy, Tharmalingam
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experimental part
p. 5692 - 5699
(2011/02/18)
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