36947-70-3Relevant academic research and scientific papers
Visible-light-mediated organoboron-catalysed metal-free dehydrogenation of N-heterocycles using molecular oxygen
Wei, Lanfeng,Wei, Yu,Xu, Liang,Zhang, Jinli
supporting information, p. 4446 - 4450 (2021/06/30)
The surge of photocatalytic transformation not only provides unprecedented synthetic methods, but also triggers the enthusiasm for more sustainable photocatalysts. On the other hand, oxygen is an ideal oxidant in terms of atom economy and environmental friendliness. However, the poor reactivity of oxygen at the ground state makes its utilization challenging. Herein, a visible-light-induced oxidative dehydrogenative process is disclosed, which uses an organoboron compound as the photocatalyst and molecular oxygen as the sole oxidant.Viathis approach, an array of N-heterocycles have been accessed under metal-free mild conditions, in good to excellent yields.
Method for preparing N - heterocyclic ring through visible light mediated dehydrogenation
-
Paragraph 0154-0159, (2021/10/02)
The invention discloses a method for preparing N - heterocyclic rings through visible light mediated dehydrogenation, and the reaction can be carried out under the conditions of room temperature and visible light without heating. The novel tetra-coordination N-N - diaryl chelating borate compound serves as a photocatalyst, so that the use of a noble metal photocatalyst is avoided, precious metal residue in the reaction product can be reduced as much as possible, and the method is more suitable for synthesizing bioactive molecules.
Preparation method 2 -substituted benzimidazole derivative
-
Paragraph 0047-0052, (2021/11/10)
The invention belongs to the field of fine chemical product production, and particularly relates to 2 -substituted benzimidazole derivative preparation method which comprises the following steps: (1) taking O-phenylenediamine and aldehyde as raw materials, carrying out catalytic condensation, cyclization and oxidation reaction in a eutectic solvent. (2) Water is added to the reaction system, the separated product is filtered, and the eutectic solvent is recycled. (3) After recrystallization, a target product is obtained. The method has the advantages of simple operation process, easily available raw materials, low cost, high purity of the target product and no catalyst participation, can effectively prevent isomer formation, and is beneficial to large-scale production.
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.
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
supporting information, p. 340 - 349 (2020/12/01)
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.
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
A heterogeneous catalytic strategy for facile production of benzimidazoles and quinoxalines from primary amines using the Al-MCM-41 catalyst
Vasu, Amrutham,Naresh, Mameda,Krishna Sai, Gajula,Divya Rohini, Yennamaneni,Murali, Boosa,Ramulamma, Madasu,Ramunaidu, Addipilli,Narender, Nama
, p. 9439 - 9446 (2021/12/09)
This study reports a straightforward heterogeneous catalytic (Al-MCM-41) approach to synthesize nitrogen heterocycle moieties from primary amines under solvent-free conditions. The Al-MCM-41 catalyst was prepared using a hydrothermal method and characterized by various analytical techniques. The probability and limitations of the catalytic methodology were presented with various substrates. The catalytic method grants an attractive route to a wide variety of benzimidazole and quinoxaline moieties with good to excellent yields. The gram scale reaction and reusability (up to five cycles) of the Al-MCM-41 catalyst would greatly benefit industrial applications. This journal is
Heterogenizing a Homogeneous Nickel Catalyst Using Nanoconfined Strategy for Selective Synthesis of Mono- And 1,2-Disubstituted Benzimidazoles
Shadab,Dey, Gargi,Sk, Motahar,Banerjee, Debasis,Aijaz, Arshad
supporting information, p. 16042 - 16047 (2021/11/04)
A homogeneous Ni-phenanthroline catalyst was successfully immobilized into the cavities of a metal-organic framework, ZIF-8. The as-synthesized heterogeneous catalyst, Ni-Phen@ZIF, represents the first MOF based catalyst that enables dehydrogenative coupling of alcohols with aromatic diamines for selective synthesis of both mono- and 1,2-disubstituted benzimidazoles. The catalyst survived under harsh basic conditions, characterized by SEM, TEM, BET, PXRD, and EDX elemental mappings. The presence of the nanoconfined Ni-phenanthroline complex and the formation of extra Lewis acid sites during catalysis in the Ni-Phen@ZIF structure, confirmed by TPD analysis and kinetic experiments, might be responsible for higher activity and selectivity.
A one-pot synthesis of benzimidazoles via aerobic oxidative condensation of benzyl alcohols with o-phenylenediamines catalyzed by [MIMPs]+Cl-/NaNO2/TEMPO
Geng, Zhenzhen,Zhang, Hong-Yu,Yin, Guohui,Zhang, Yuecheng,Zhao, Jiquan
, p. 557 - 565 (2020/03/30)
The ionic liquid 1-methyl-3-(3-sulfopropyl)imidazolium chloride ([MIMPs]+Cl-) in combination with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and sodium nitrite (NaNO2) as a catalytic system demonstrates high efficiency in the one-pot two-step aerobic oxidative condensation of benzyl alcohols with 1,2-phenylenediamines to give benzimidazoles. Various benzimidazoles are obtained in good to excellent yields by this strategy.
A Green, Scalable, One-Minute Synthesis of Benzimidazoles
Elumalai, Vijayaragavan,Hansen, Jorn H.
supporting information, p. 547 - 552 (2020/03/27)
Herein is reported a substantially improved synthesis of 2-substituted benzimidazoles by condensation of 1,2-diaminoarenes and aldehydes using methanol as the reaction medium. The developed method afforded moderate to excellent yields (33-96percent) at am
