5805-30-1Relevant academic research and scientific papers
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.
Photochemical Synthesis of Benzimidazoles from Diamines and Aldehydes
Skolia, Elpida,Apostolopoulou, Mary K.,Nikitas, Nikolaos F.,Kokotos, Christoforos G.
supporting information, p. 422 - 428 (2020/12/13)
An efficient, green, cheap, and metal-free photochemical protocol for the synthesis of benzimidazoles has been developed. 2,2-Dimethoxy-2-phenylacetophenone was employed as the photoinitiator and CFL lamps were used as the light source, leading to the cyc
Additive- and Oxidant-Free Expedient Synthesis of Benzimidazoles Catalyzed by Cobalt Nanocomposites on N-Doped Carbon
Wang, Zhaozhan,Song, Tao,Yang, Yong
supporting information, p. 319 - 324 (2019/02/12)
A one-pot direct synthesis of a wide range of biologically active benzimidazoles through coupling of phenylenediamines and aldehydes catalyzed by a highly recyclable nonnoble cobalt nanocomposite was developed. A broad set of benzimidazoles can be efficiently synthesized in high yields and with good functional-group tolerance under additive- and oxidant-free mild conditions. The catalyst can be easily recycled for successive uses, and the process permits gram-scale syntheses of benzimidazoles.
An efficient one-pot conversion of carboxylic acids into benzimidazoles via an HBTU-promoted methodology
Barasa, Leonard,Yoganathan, Sabesan
, p. 35824 - 35830 (2018/10/31)
Benzimidazole is a privileged, and routinely used pharmacophore in the drug discovery process. Herein, we report a mild, acid-free and one-pot synthesis of indole, alkyl and alpha-amino benzimidazoles through a novel HBTU-promoted methodology. An extensive library of indole-carboxylic acids, alkyl carboxylic acids and N-protected alpha-amino acids has been converted into the corresponding benzimidazoles in 80-99% yield. Since alpha-aminobenzimidazoles are highly useful synthons as chiral ligands for chemical catalysis, as well as for drug discovery endeavors, our reported method provides direct access to this scaffold in a simple, one-pot operation from commercially available carboxylic acids.
An Efficient Synthesis of 2-Substituted Benzimidazoles via Photocatalytic Condensation of o-Phenylenediamines and Aldehydes
Kovvuri, Jeshma,Nagaraju, Burri,Kamal, Ahmed,Srivastava, Ajay K.
supporting information, p. 644 - 650 (2016/10/21)
A photocatalytic method has been developed for the efficient synthesis of functionalized benzimidazoles. This protocol involves photocatalytic condensation of o-phenylenediamines with various aldehydes using the Rose Bengal as photocatalyst. The method was found to be general and was successfully employed for accessing pharmaceutically important benzimidazoles by the condensation of aromatic, heteroaromatic and aliphatic aldehydes with o-phenylenediamines, in good-to-excellent yields. Notably, the method was found to be effective for the condensation of less reactive heterocyclic aldehydes with o-phenylenediamines.
Isocyanurate-based periodic mesoporous organosilica (PMO-ICS): A highly efficient and recoverable nanocatalyst for the one-pot synthesis of substituted imidazoles and benzimidazoles
Dekamin, Mohammad G.,Arefi, Elham,Yaghoubi, Amene
, p. 86982 - 86988 (2016/10/19)
Isocyanurate bridging periodic mesoporous organosilica (PMO-ICS) was shown to be a highly active and efficient recyclable catalyst for the three-component synthesis of imidazole derivatives from benzoin, different aldehydes and ammonium acetate under mild reaction conditions in short reaction times and good to excellent yields in EtOH. Also, benzimidazole derivatives were efficiently prepared from o-phenylenediamine and different aldehydes in the presence of PMO-ICS. Moreover, the catalyst was also recovered and reused at least four times without a significant decrease in its activity. The PMO-ICS catalyst was characterized by Fourier transformer infrared (FTIR) spectroscopy, thermogravimetry analysis (TGA), powder X-ray diffraction (XRD) and nitrogen adsorption-desorption isotherm (NADI) techniques as well as field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Compared to the classical methodologies, this method illustrated significant advantages including low loading of the catalyst, avoiding the use of toxic transition metals or reactive reagents for modification of the catalytic activity, short reaction times, high to excellent yields, easy separation and purification of the products, and reusability of the catalyst.
An efficient one-pot two catalyst system in the construction of 2-substituted benzimidazoles: Synthesis of benzimidazo[1,2-c]quinazolines
Cimarelli, Cristina,Di Nicola, Matteo,Diomedi, Simone,Giovannini, Riccardo,Hamprecht, Dieter,Properzi, Roberta,Sorana, Federico,Marcantoni, Enrico
, p. 11687 - 11695 (2015/12/08)
The benzimidazole core is a common moiety in a large number of natural products and pharmacologically active small molecules. The synthesis of novel benzimidazole derivatives remains a main focus in medicinal research. In continuation of the efforts towards Ce(iii) catalysts for organic transformations, we observed for the first time the activity of the iodide ion and copper cation in activating CeCl3·7H2O in the selective formation of prototypical 2-substituted benzimidazoles. The one-pot CeCl3·7H2O-CuI catalytic system procedure includes the cyclo-dehydrogenation of aniline Schiff's bases, generated in situ from the condensation of 1,2-phenylenediamine and aldehydes, followed by the oxidation with iodine, which works as a hydrogen sponge. Mild reaction conditions, good to excellent yields, and clean reactions make the procedure a useful contribution to the synthesis of biologically active fused heterocycles containing benzimidazoquinazolines.
Synthetic Method of Benzimidazole via Aerobic Oxidation
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Paragraph 0104; 0110; 0192; 0193, (2016/11/14)
The present invention relates to a method which naturally synthesizes benzimidazole by reacting aryl diamine and aldehyde through using aerobic oxidative cyclization which uses water or alkali metal halide as a catalyst, and oxygen or oxygen in the air as an oxidizing agent, under DMF or an alcohol solvent.
One-pot synthesis of benzimidazoles in water in the presence of SiO 2-OPO3H
Mirjalili,Bamoniri,Rahimi Kazerouni
, p. 35 - 40 (2014/05/06)
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.
Visible-light-promoted synthesis of benzimidazoles
Park, Sehyun,Jung, Jaehun,Cho, Eun Jin
, p. 4148 - 4154 (2014/07/08)
A simple and environmentally-friendly synthetic method for benzimidazoles, which are important structural motifs in many applications owing to their various biological functions, has been developed. The reaction of o-phenylenediamine and a variety of aliphatic/aromatic aldehydes in methanol proceeds at room temperature with only natural sources, molecular oxygen and visible light. A simple and eco-friendly synthetic method for benzimidazoles, which are important structural motifs in many applications owing to their various biological functions, has been developed. The reaction of o-phenylenediamine and a variety of aliphatic/aromatic aldehydes in methanol proceeds at room temperature with only natural sources, molecular oxygen and visible light. Copyright
