77738-96-6Relevant articles and documents
One-pot, multi-component synthesis of ethyl (E)-1-(3-ethoxy-3-oxoprop-1-en-1-yl)-2-aryl-2,5-dihydro-1H-benzo[b][1,4]diazepine-3-carboxylate derivatives
Tan, Hong-bo,Wang, Yin-feng,Xu, Jia,Hu, Chun-sheng
, (2020)
A new methodology for the synthesis of novel benzo[b][1,4]diazepine derivatives via a one-pot, multi-component reaction of benzaldehyde, o-phenylenediamine, and ethyl propiolate has been developed. Readily available starting materials, operationally simpl
An Unexpected Formation of 2-Arylbenzimidazoles from α,α-Diiodo-α’-acetoxyketones and o-Phenylenediamines
Sadhukhan, Santu,Mondal, Swagata,Baire, Beeraiah
, (2022/03/01)
An unusual reactivity of the α,α-diiodo-α’-acetoxyketones with o-phenylenediamines is reported through the formation of 2-arylbenzimidazoles. A systematic study through a series of fruitful control experiments and isolation of key intermediates unravelled the unprecedented domino mechanism. This process involves a stepwise two-carbon fragmentation pathway through domino and sequential amidation–aziridination–decarbonylation–I2-mediated aminative cyclization–oxidation reactions. This strategy employs no additives like oxidant, metal catalyst, bases, and represents yet another novel reactivity profile of the building blocks α,α-diiodo-α’-acetoxyketones.
Visible-Light Photoredox Catalyzed Double C-H Functionalization: Radical Cascade Cyclization of Ethers with Benzimidazole-Based Cyanamides
Jiang, Si,Tian, Xiao-Jing,Feng, Shu-Yao,Li, Jiang-Sheng,Li, Zhi-Wei,Lu, Cui-Hong,Li, Chao-Jun,Liu, Wei-Dong
supporting information, p. 692 - 696 (2021/02/01)
A visible-light photoredox catalyzed radical cascade cyclization of simple ethers with cyanamides is developed at room temperature. This strategy involves sequential inert Csp3-H/Csp2-H functionalizations through intermolecular addition reaction of oxyalkyl radicals to N-cyano groups followed by radical cyclization of iminyl radicals in situ generated with C-2 aryl rings. This method allows for efficient synthesis of tetracyclic benzo[4,5]imidazo[1,2-c]quinazolines. Importantly, this is the first example of an intermolecular-intramolecular radical cascade cyclization reaction of cyanamides.
UV-visible light-induced photochemical synthesis of benzimidazoles by coomassie brilliant blue coated on W-ZnO@NH2nanoparticles
Chen, Ruijuan,Jalili, Zahra,Tayebee, Reza
, p. 16359 - 16375 (2021/05/19)
Heterogeneous photocatalysts proffer a promising method to actualize eco-friendly and green organic transformations. Herein, a new photochemical-based methodology is disclosed in the preparation of a wide range of benzimidazoles through condensation of o-phenylenediamine with benzyl alcohols in the air under the illumination of an HP mercury lamp in the absence of any oxidizing species catalyzed by a new photocatalyst W-ZnO@NH2-CBB. In this photocatalyst, coomassie brilliant blue (CBB) is heterogenized onto W-ZnO@NH2 to improve the surface characteristics at the molecular level and enhance the photocatalytic activity of both W-ZnO@NH2 and CBB fragments. This unprecedented heterogeneous nanocatalyst is also identified by means of XRD, FT-IR, EDS, TGA-DTG, and SEM. The impact of some influencing parameters on the synthesis route and effects on the catalytic efficacy of W-ZnO@NH2-CBB are also assessed. The appropriate products are attained for both the electron-withdrawing and electron-donating substituents in the utilized aromatic alcohols. Furthermore, preparation of benzimidazoles is demonstrated to occur mainly via a radical mechanism, which shows that reactive species such as ·O2-, OH and h+ would be involved in the photocatalytic process. Stability and reusability studies also warrant good reproducibility of the nanophotocatalyst for at least five runs. Eventually, a hot filtration test proved that the nanohybrid photocatalyst is stable in the reaction medium. Using an inexpensive catalyst, UV-vis light energy and air, as a low cost and plentiful oxidant, puts this methodology in the green chemistry domain and energy-saving organic synthesis strategies. Finally, the anticancer activity of W-ZnO nanoparticles is investigated on MCF7 breast cancer cells by MTT assay. This experiment reveals that the mentioned nanoparticles have significant cytotoxicity towards the selected cell line.
Solvent-dependent metal-free chemoselective synthesis of benzimidazoles and 1,3,5-triarylbenzenes from 2-amino anilines and aryl alkyl ketones catalyzed by I2
Ding, Yuxin,Ma, Renchao,Ma, Yongmin
supporting information, (2021/04/09)
A solvent-dependent I2-catalyzed chemoselective reaction was developed for the synthesis of benzimidazoles and 1,3,5-triarylbenzenes via the annulation of 2-amino anilines and aryl alkyl ketones or the cyclization of aryl alkyl ketones, respectively. With 1,4-dioxane as the solvent, sequential C[sbnd]N bond formation followed by C(CO)-C(CH3) bond cleavage leads to the formation of benzimidazoles in a highly selective manner while aldol-type self-condensation of aryl alkyl ketones predominates using PhNO2 or PhCl as the solvent to afford 1,3,5-triarylbenzenes.
Transition-Metal-Free Transfer Hydrogenative Cascade Reaction of Nitroarenes with Amines/Alcohols: Redox-Economical Access to Benzimidazoles
Gujjarappa, Raghuram,Kabi, Arup K.,Malakar, Chandi C.,Musib, Dulal,Roy, Anupam,Sahoo, Abhishek,Singh, Virender,Vodnala, Nagaraju
, p. 14597 - 14607 (2021/11/12)
This report describes an efficient transition-metal-free process toward the transfer hydrogenative cascade reaction between nitroarenes and amines or alcohols. The developed redox-economical approach was realized using a combination of KOtBu and Et3SiH as reagents, which allows the synthesis of benzimidazole derivatives via σ-bond metathesis. The reaction conditions hold well over a wide range of substrates embedded with diverse functional groups to deliver the desired products in good to excellent yields. The mechanistic proposal has been depicted on the basis of a series of control experiments, mass spectroscopic evidence which is well supported by density functional theory (DFT) calculations with a feasible energy profile.
Al2O3/CuI/PANI nanocomposite catalyzed green synthesis of biologically active 2-substituted benzimidazole derivatives
Chandra, Ramesh,Hooda, Sunita,Kohli, Sahil,Rathee, Garima
, p. 7750 - 7758 (2021/06/16)
This work is generally focused on the synthesis of an efficient, reusable and novel heterogeneous Al2O3/CuI/PANI nanocatalyst, which has been well synthesized by a simple self-assembly approach where aniline is oxidized into PANI and
Bandgap engineering in benzotrithiophene-based conjugated microporous polymers: a strategy for screening metal-free heterogeneous photocatalysts
Han, Songjie,Li, Ziping,Ma, Si,Zhi, Yongfeng,Xia, Hong,Chen, Xiong,Liu, Xiaoming
supporting information, p. 3333 - 3340 (2021/02/26)
Metal-free conjugated microporous polymers (CMPs) as visible-light active and recyclable photocatalysts offer a green and sustainable alternative to classical metal-based photosensitizers. However, the strategy for screening CMP-based heterogeneous photocatalysts has not been interpreted up to now. Herein, we present a general strategy for obtaining excellent solid photocatalysts, which is to implement bandgap engineering in the same series of materials. As a proof of concept, three conjugated porous materials containing benzo[1,2-b:3,4-b′:5,6-b′′]trithiophene building blocks (BTT-CMP1, BTT-CMP2 and BTT-CMP3) were successfully constructed. They possess permanent porosity with a large specific surface area and excellent stability. By changing the linker between benzotrithiophene units, the bandgaps, energy levels and photoelectric performances including the absorption, transient photocurrent responses and photocatalytic performances of BTT-CMPs could be handily modulated. Indeed, BTT-CMP2 displayed the best catalytic activity for visible-light-induced synthesis of benzimidazoles among the three CMP materials, even higher than that of small molecule photocatalysts. As a metal-free photocatalyst, interestingly, the screened BTT-CMP2 also showed extensive substrate applicability and outstanding recyclability. Additionally, we have the opinion that this strategy will prove to be a guiding principle for screening superior CMP-based photocatalysts and broaden their application fields.
Benzotrithiophene and triphenylamine based covalent organic frameworks as heterogeneous photocatalysts for benzimidazole synthesis
Chen, Ying,Huo, Jianqiang,Luo, Bingcai,Zhang, Yubao
, p. 52 - 60 (2021/08/27)
Metal-free covalent organic frameworks (COFs) as visible-light active and recyclable photocatalysts afford an eco-friendly and sustainable option to classical photosensitizers, which usually require noble metals (iridium, ruthenium, rhodium, etc.) to produce photocatalytic activity. Most classical small molecule photosensitizers have poor recyclability with certain limitations. As a result, it is of great significance to develop a metal-free and easily recyclable COF photocatalyst. In this study, we designed and synthesized a new type of COF photocatalyst (BTT-TPA-COF) in which benzotrithiophene and triphenylamine units are alternately connected. It has high specific surface area, permanent porosity and good stability. In addition, this design strategy can effectively adjust the band gap, energy level and photoelectric performance of BTT-TPA-COF. As a metal-free photocatalyst, BTT-TPA-COF exhibits high-efficiency photocatalytic activity, excellent substrate tolerance and excellent recyclability for the synthesis of 2-arylbenzimidazole compounds. This research not only puts forward a design strategy for high-efficiency photocatalysts, but also broadens the application range of COF materials in photocatalytic organic reactions.
Reusable nano-zirconia-catalyzed synthesis of benzimidazoles and their antibacterial and antifungal activities
Ahmad, Naushad,Ahmed, Faheem,Albalawi, Fadwa,Alomar, Suliman Yousef,Basaveswara Rao, M. V.,Cheedarala, Ravi Kumar,Naidu, Tentu Manohra,Rao, Nalla Krishna,Rao, Tentu Nageswara,Reddy, G. Rajasekhar
, (2021/07/26)
In this article, a zirconia-based nano-catalyst (Nano-ZrO2 ), with intermolecular C-N bond formation for the synthesis of various benzimidazole-fused heterocycles in a concise method is reported. The robustness of this reaction is demonstrated
