21627-71-4Relevant articles and documents
Selective C-C bonds formation, N-alkylation and benzo[d]imidazoles synthesis by a recyclable zinc composite
Zhu, Guanxin,Duan, Zheng-Chao,Zhu, Haiyan,Ye, Dongdong,Wang, Dawei
supporting information, p. 266 - 270 (2021/08/06)
Earth abundant metals are much less expensive, promising, valuable metals and could be served as catalysts for the borrowing hydrogen reaction, dehydrogenation and heterocycles synthesis, instead of noble metals. The uniformly dispersed zinc composites were designed, synthesized and carefully characterized by means of XPS, EDS, TEM and XRD. The resulting zinc composite showed good catalytic activity for the N-alkylation of amines with amines, ketones with alcohols in water under base-free conditions, while unsaturated carbonyl compounds could also be synthesized by tuning the reaction conditions. Importantly, it was the first time to realize the synthesis of 2-aryl-1H-benzo[d]imidazole derivatives by using this zinc composite under green conditions. Meanwhile, this zinc catalyst could be easily recovered and reused for at least five times.
Graphene oxide-catalyzed CSp3–H activation of methylarenes in aqueous medium: A unified metal-free access to amides and benzimidazoles
Dandia, Anshu,Mahawar, Dinesh Kumar,Sharma, Ruchi,Badgoti, Ranveer Singh,Rathore, Kuldeep S.,Parewa, Vijay
, (2019/09/12)
Graphene oxide (GO)-catalyzed selective synthesis of amides via CSp3–H activation of methylarenes and consequent C–N bond formation with anilines under aqueous medium has been described. Oxygen functionality allied with GO surface played a dual role both as acid catalyst and oxidizing agent to some extent. However, GO has a copious effect on the reaction, shown by a high TOF value with TBHP as co-oxidant. The decisive role of carboxylic acid functional groups on GO nanosheets in this metal-free strategy has been confirmed and was monitored by various analytic techniques viz. Fourier transform-infrared, UV–Vis, Raman and XPS. A plausible mechanism was proposed by control experiments and by the isolation of the intermediate. Over-oxidation of methylarenes was not detected, and high recyclability of the carbocatalyst with its heterogeneous behavior facilitated the isolation and purification of the desired products. We have further explored the utility of this process for the chemoselective synthesis of benzimidazoles.
Magnetically separable MnFe2O4 nano-material: An efficient and reusable heterogeneous catalyst for the synthesis of 2-substituted benzimidazoles and the extended synthesis of quinoxalines at room temperature under aerobic conditions
Brahmachari, Goutam,Laskar, Sujay,Barik, Puspendu
, p. 14245 - 14253 (2013/09/02)
A simple and efficient protocol has been developed for the synthesis of biologically relevant 2-substituted benzimidazoles and quinoxalines using magnetically separable manganese ferrite (MnFe2O4) nanopowder for the first time as a reusable heterogeneous catalyst at room temperature under aerobic conditions. MnFe2O4 nanoparticles were prepared by a simple sol-gel method using starch as a bio-polymeric matrix, and characterized by XRD, TEM, EDAX and VSM analyses. The Royal Society of Chemistry 2013.
