848142-03-0Relevant articles and documents
1,2-Disubstituted Benzimidazoles by the Iron Catalyzed Cross-Dehydrogenative Coupling of Isomeric o-Phenylenediamine Substrates
Foss, Frank W.,Palacios, Philip M.,Pierce, Brad S.,Thapa, Pawan,Tran, Tam
, p. 1991 - 2009 (2020/03/13)
Benzimidazoles are common in nature, medicines, and materials. Numerous strategies for preparing 2-arylbenzimidazoles exist. In this work, 1,2-disubstituted benzimidazoles were prepared from various mono- and disubstituted ortho-phenylenediamines (OPD) by iron-catalyzed oxidative coupling. Specifically, O2 and FeCl3·6H2O catalyzed the cross-dehydrogenative coupling and aromatization of diarylmethyl and dialkyl benzimidazole precursors. N,N′-Disubstituted-OPD substrates were significantly more reactive than their N,N-disubstituted isomers, which appears to be relative to their propensity for complexation and charge transfer with Fe3+. The reaction also converted N-monosubstituted OPD substrates to 2-substituted benzimidazoles; however, electron-poor substrates produce 1,2-disubstituted benzimidazoles by intermolecular imino-transfer. Kinetic, reagent, and spectroscopic (UV-vis and EPR) studies suggest a mechanism involving metal-substrate complexation, charge transfer, and aerobic turnover, involving high-valent Fe(IV) intermediates. Overall, comparative strategies for the relatively sustainable and efficient synthesis of 1,2-disubstituted benzimidazoles are demonstrated.
Metal-free TEMPO-promoted C(sp3)-H amination to afford multisubstituted benzimidazoles
Xue, Ding,Long, Ya-Qiu
, p. 4727 - 4734 (2014/06/09)
An efficient TEMPO-air/cat. TEMPO-O2 oxidative protocol was developed to synthesize multisubstituted or fused tetracyclic benzimidazoles via a metal-free oxidative C-N coupling between the sp3 C-H and free N-H of readily available N1-benzyl/alkyl-1,2-phenylenediamines.
In vitro anti-glycation and anti-oxidant properties of synthesized schiff bases
Jhaumeer-Laulloo, Sabina,Bhowon, Minu Gupta,Mungur, Shabneez,Mahomoodally, Mohamad Fawzi,Subratty, Anwar Hussein
experimental part, p. 409 - 414 (2012/09/25)
A series of mono, bis and mixed Schiff bases (1-7) were synthesised and evaluated for potential anti-glycation and anti-oxidant activities using the bovine serum albumin - glucose assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay respectiv
Facile, regioselective syntheses of N-alkylated 2,3-diaminopyridines and imidazo[4,5-b]pyridines
Khanna,Weier,Lentz,Swenton,Lankin
, p. 960 - 965 (2007/10/02)
Useful strategies are reported for the differentiation and selective synthetic manipulations of amino groups at the 2- and 3-positions of pyridines. It has been found that 2,3-diaminopyridine reacts with aldehydes under reductive amination conditions to g
Antinuclear Agents. 1. Gastric Antisecretory and Cytoprotective Properties of Substituted Imidazopyridines
Kaminski, James J.,Bristol, James A.,Puchalski, Chester,Lovey, Raymond G.,Elliott, Arthur J.,et al.
, p. 876 - 892 (2007/10/02)
A novel class of antinuclear agents, the substituted imidazopyridines, is described.The present compounds are not histamine (H2) receptor antagonists nor are they prostaglandin analoques, yet they exhibit both gastric antisecretory and c
