14313-45-2Relevant academic research and scientific papers
Synthesis of novel tetra-substituted benzimidazole compounds containing certain heterostructures with antioxidant and anti-urease activities
Aydin, Serdar,Baltas, Nimet,Karaali, Nesrin,Mentese, Emre
, (2020)
A new series of 5,6-dimethyl-2-phenyl-1H-benzimidazole derivatives was synthesized. The antioxidant activities of the synthesized compounds were determined according to the cupric reducing antioxidant capacity (CUPRAC), ABTS, and DPPH assays. Many of the target compounds showed good antioxidant activity. Among these compounds, it has been determined that the carbothioamide and 1,2,4-triazole derivatives had a very good antioxidant capacity. Also, all compounds were screened for in vitro inhibitory activity against Jack bean urease. Among the synthesized molecules, the starting compound, acetate, and acetohydrazide derivatives (with IC50 values 12.02, 11.40, and 8.04 μg/mL, respectively) had a higher inhibitory effect on urease and exhibited a lower IC50 values than acetohydroxamic acid (IC50: 20.50 μg/mL) and thiourea (IC50: 14.04 μg/mL) as a reference inhibitors.
ZNCL2 - promoted synthesis of benzimidazoles under microwave irradiation
Rostamizadeh, Shahnaz,Nojavan, Masoomeh,Heshmatpoor
, p. 305 - 310 (2007)
Benzimidazoles 3a-f have been prepared in a few seconds from the reaction of ophenylene-diamine 1 and β-ketoesters 2 on the surface of silica gel and ZnCl2 under microwave irradiation in excellent yield. The reaction has also gone very well in MeOH and in the presence of ZnCl2 under reflux condition.
One-Pot Transformation of Lignin and Lignin Model Compounds into Benzimidazoles
Guo, Tao,He, Jianghua,Liu, Tianwei,Zhang, Yuetao
, (2022/02/07)
It is a challenging task to simultaneously achieve selective depolymerization and valorization of lignin due to their complex structure and relatively stable bonds. We herein report an efficient depolymerization strategy that employs 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as oxidant/catalyst to selectively convert different oxidized lignin models to a wide variety of 2-phenylbenzimidazole-based compounds in up to 94 % yields, by reacting with o-phenylenediamines with varied substituents. This method could take full advantage of both Cβ and/or Cγ atom in lignin structure to furnish the desirable products instead of forming byproducts, thus exhibiting high atom economy. Furthermore, this strategy can effectively transform both the oxidized hardwood (birch) and softwood (pine) lignin into the corresponding degradation products in up to 45 wt% and 30 wt%, respectively. Through a “one-pot” process, we have successfully realized the oxidation/depolymerization/valorization of natural birch lignin at the same time and produced the benzimidazole derivatives in up to 67 wt% total yields.
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.
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.
Preparation method of 2-substituted benzimidazole compound
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Paragraph 0079-0083, (2021/02/20)
The invention discloses a preparation method of a 2-substituted benzimidazole compound, and belongs to the field of synthesis of benzimidazole compounds. The 2-substituted benzimidazole compound is synthesized in an organic solvent by taking an o-nitroaniline compound, aromatic aldehyde, o-dinitrobenzene and aromatic aldehyde as raw materials and taking Co particles wrapped by a nitrogen-doped carbon material as a catalyst. According to the method, the 2-substituted benzimidazole compound can be prepared at room temperature, the reaction conditions are mild, the yield is as high as 95%, the selectivity is as high as 99%, and the method is economical, environmentally friendly and wide in substrate applicability. The used catalyst is easy to prepare, low in cost and good in reusability, canbe separated by utilizing magnetism, and is convenient to recover, so that the method has a relatively strong industrial application prospect.
s-Tetrazine-functionalized hyper-crosslinked polymers for efficient photocatalytic synthesis of benzimidazoles
An, Wan-Kai,Zheng, Shi-Jia,Zhang, Hui-Xing,Shang, Tian-Tian,Wang, He-Rui,Xu, Xiao-Jing,Jin, Qiu,Qin, Yuchen,Ren, Yunlai,Jiang, Song,Xu, Cui-Lian,Hou, Mao-Song,Pan, Zhenliang
supporting information, p. 1292 - 1299 (2021/02/26)
Developing green-safe, efficient and recyclable catalysts is crucial for the chemical industry. So far, organic photocatalysis has been proved to be an environmentally friendly and energy-efficient synthetic technology compared with traditional metal catalysis. As a versatile catalytic platform, hyper-crosslinked polymers (HCPs) with large surface area and high stability are easily prepared. In this report, we successfully constructed two porous HCP photocatalysts (TZ-HCPs) featurings-tetrazine units and surface areas larger than 700 m2g?1through Friedel-Crafts alkylation reactions. The rational energy-band structures and coexisting micro- and mesopores endow TZ-HCPs with excellent activities to realize the green synthesis of benzimidazoles (28 examples, up to 99% yield, 0.5-4.0 h) in ethanol. Furthermore, at least 21 iterative catalytic runs mediated by TZ-HCP1D were performed efficiently, with 96-99% yield. This study of TZ-HCPs sheds light on the wide-ranging prospects of application of HCPs as metal-free and green photocatalysts for the preparation of fine chemicals.
Synthesis of sulfonylated benzimidazo[2,1-a]isoquinolin-6(5H)-ones via I2O5-induced radical relay addition/cyclization of activated alkenes with sulfonylhydrazides
Tang, Yucai,Yang, Meng,Wang, Feifei,Hu, Xia,Wang, Gang
supporting information, (2021/03/01)
A facile I2O5 induced radical relay addition/cyclization of activated alkenes with sulfonylhydrazides has been successfully developed, leading to a broad range of sulfonylated benzimidazo[2,1-a]isoquinolin-6(5H)-ones in moderate to good yields. The protocol has advantages of a metal-, base-, acid-, peroxide-free process, simple operation, and broad functional group tolerance.
Visible-Light-Induced Deaminative Alkylation/Cyclization of Alkyl Amines with N-Methacryloyl-2-phenylbenzoimidazoles in Continuous-Flow Organo-Photocatalysis
Ramesh, Vankudoth,Gangadhar, Maram,Nanubolu, Jagadeesh Babu,Adiyala, Praveen Reddy
supporting information, p. 12908 - 12921 (2021/09/18)
Herein, we present a metal-free visible-light-induced eosin-y-catalyzed deaminative strategy for the sequential alkylation/cyclization of N-methacryloyl-2-phenylbenzoimidazoles with alkyl amine-derived Katritzky salts, which provides an efficient avenue for the construction of various benzo[4,5]imidazo[2,1-a]isoquinolin-6(5H)-one derivatives in moderate to excellent yields under mild reaction conditions. The key enabling feature of this novel reaction includes utilization of redox-active pyridinium salts from abundant and inexpensive primary amine feedstocks that were converted into alkyl radicals via C-N bond scission and subsequent alkylation/cyclization with N-methacryloyl-2-phenylbenzoimidazoles by the formation of two new C-C bonds. In addition, we implemented this protocol for a variety of amino acids, affording the products in moderate yields. Moreover, the novel, environmentally benign batch protocol was further carried out in a continuous-flow regime by utilizing a perfluoroalkoxy alkane tubing microreactor under optimized reaction conditions with a blue light-emitting diode light source, enabling excellent yields and a shorter reaction time (19 min) versus the long reaction time (16 h) of the batch reaction. The reaction displays excellent functional group tolerance, easy operation, scalability, mild reaction conditions, and broad synthetic utility.
H2 Activation with Co Nanoparticles Encapsulated in N-Doped Carbon Nanotubes for Green Synthesis of Benzimidazoles
Lin, Chuncheng,Wan, Weihao,Wei, Xueting,Chen, Jinzhu
, p. 709 - 720 (2020/11/30)
Co nanoparticles (NPs) encapsulated in N-doped carbon nanotubes (Co@NC900) are systematically investigated as a potential alternative to precious Pt-group catalysts for hydrogenative heterocyclization reactions. Co@NC900 can efficiently catalyze hydrogenative coupling of 2-nitroaniline to benzaldehyde for synthesis of 2-phenyl-1H-benzo[d]imidazole with >99 % yield at ambient temperature in one step. The robust Co@NC900 catalyst can be easily recovered by an external magnetic field after the reaction and readily recycled for at least six times without any evident decrease in activity. Kinetic experiments indicate that Co@NC900-promoted hydrogenation is the rate-determining step with a total apparent activation energy of 41±1 kJ mol?1. Theoretical investigations further reveal that Co@NC900 can activate both H2 and the nitro group of 2-nitroaniline. The observed energy barrier for H2 dissociation is only 2.70 eV in the rate-determining step, owing to the presence of confined Co NPs in Co@NC900. Potential industrial application of the earth-abundant and non-noble transition metal catalysts is also explored for green and efficient synthesis of heterocyclic compounds.
