100880-52-2Relevant articles and documents
N-Doped Cationic PAHs by Rh(III)-Catalyzed Double C-H Activation and Annulation of 2-Arylbenzimidazoles with Alkynes
Villar, José M.,Suárez, Jaime,Varela, Jesús A.,Saá, Carlos
, p. 1702 - 1705 (2017)
A novel class of N-doped cationic PAHs (polycyclic aromatic hydrocarbons) bearing the benzo[c,d]fluoranthene scaffold has been synthesized by the Rh(III)-catalyzed double-oxidative annulation of 2-arylbenzimidazoles with alkynes. The overall process involves a double C-N bond formation through a double C-H/N-H functionalization.The solid-state structures and electronic properties of the new N-doped PAHs were analyzed. These cationic azapolycycles were readily reduced in the presence of LiAlH4 or by the addition of PhLi to give interesting phenyl and diphenylmethanediamine derivatives.
Oxidative Radical Relay Functionalization for the Synthesis of Benzimidazo[2,1-a]iso-quinolin-6(5H)-ones
Sun, Kai,Li, Guofeng,Li, Yuyang,Yu, Jie,Zhao, Qing,Zhang, Zhiguo,Zhang, Guisheng
, p. 1947 - 1954 (2020)
Here, a mild and general oxidative radical relay carbocyclization reaction with 2-arylbenzoimidazoles and cyclic ethers is reported. This method provides an efficient access to a wide range of structurally diverse benzimidazo[2,1-a]isoquinoline-6(5H)-ones under metal-free conditions. The wide substrate scope, good functional group tolerance, and scale-up operation of this method are expected to promote its potential applications in biotechnology and pharmacy. (Figure presented.).
Water extract of onion catalyst: An economical green route for the synthesis of 2-substituted and 1,2-disubstituted benzimidazole derivatives with high selectivity
Kaliyan, Prabakaran,Selvaraj, Loganathan,Muthu, Seenivasa Perumal
, p. 340 - 349 (2021)
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.
One-pot synthesis of benzimidazoles in water in the presence of SiO 2-OPO3H
Mirjalili,Bamoniri,Rahimi Kazerouni
, p. 35 - 40 (2014)
Silica-bound phosphoric acid (SiO2-OPO3H), as an eco-friendly, reusable, and heterogeneous catalyst, was applied for synthesis of 2-substituted benzimidazoles in water at 70°C. Very short reaction times, clean work-up, and high yields are among the advantages of this protocol.
Significant facilitation of metal-free aerobic oxidative cyclization of imines with water in synthesis of benzimidazoles
Lee, Ye-Sol,Cho, Yeon-Ho,Lee, Seungjae,Bin, Jong-Kwan,Yang, Joonghwan,Chae, Geesung,Cheon, Cheol-Hong
, p. 532 - 538 (2015)
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.
Copper-catalyzed radical cascade cyclization for synthesis of CF3-containing tetracyclic benzimidazo[2,1-: A] iso-quinolin-6(5 H)-ones
Sun, Kai,Li, Guofeng,Guo, Sa,Zhang, Zhiguo,Zhang, Guisheng
, p. 375 - 378 (2021)
Here, a general copper-catalyzed radical cascade carbocyclization reaction with 2-arylbenzoimidazoles and a Togni reagent was realized. Structurally diverse CF3-containing tetracyclic core benzimidazo[2,1-a]isoquinoline-6(5H)-ones were obtained in moderat
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.
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.
