Transition-Metal-Free Synthesis of Benzimidazoles Mediated by KOH/DMSO
摘要:
Benzimidazoles are prepared by intramolecular N-arylations of amidines mediated by potassium hydroxide in DMSO at 120 degrees C. In this manner, diversely substituted products have been obtained in moderate to very good yields.
An easy one-step photocatalytic synthesis of 1-aryl-2-alkylbenzimidazoles by platinum loaded TiO2 nanoparticles under UV and solar light
作者:K. Selvam、M. Swaminathan
DOI:10.1016/j.tetlet.2011.04.090
日期:2011.6
One-potsynthesis of disubstituted benzimidazoles from N-substituted 2-nitroanilines or 1,2-diamines with 3–12 nm-sized platinum particles loaded on the TiO2 using solar and UV-A light is described. 1-Aryl-2-alkylbenzimidazoles from 2-nitrodiphenylamines are formed by combined redox photocatalyticreaction, condensation and catalytic dehydrogenation on Pt-TiO2. In case of diamines, this reaction is
zinc‐promoted rearrangement of oxime acetates with arylamines for the synthesis of amidines has been developed under mild conditions. This process involves N−O/C−C bond cleavages and C−C/C−N bond formations. Various oxime acetates and arylamines are suitable for this transformation. Furthermore, diverse arylbenzimidazoles could also be prepared through simple one‐pot procedure.
在温和的条件下,已开发出一种有效且直接的锌促进肟肟与芳胺的锌促进重排以合成for的方法。此过程涉及N / O / C-C键断裂和C-C / C-N键形成。各种肟乙酸酯和芳胺适合于该转化。此外,还可以通过简单的一锅法制备各种芳基苯并咪唑。
Reactivity-Controlled Regioselectivity: A Regiospecific Synthesis of 1,2-Disubstituted Benzimidazoles
作者:Xiaohu Deng、Neelakandha S. Mani
DOI:10.1002/ejoc.200901056
日期:2010.2
combination of N 1 /N 2 chemoselectivity on the amidine and reactivity-controlled X 1 /X 2 chemoselectivity on the 1,2-dihaloarene. This reaction proves to be fairly general for the regiospecificsynthesis of 1,2-substituted benzimidazoles.