A novel efficient method for the selective synthesis of 2-substituted benzimidazoles is described through condensation reaction of o-phenylenediamines with a wide rang of aliphatic, aromatic and heteroaromatic aldehyde substrates using Brönsted acidic ionic liquid as a reusable catalyst under metal-free conditions at ambient temperature. Notably, Dodecylimidazolium hydrogen sulfate ([DodecIm][HSO4])
2,3-Dichloro-5,6-dicyano-1,4-benzoquinone, a mild catalyst for the formation of carbon-nitrogen bonds
作者:Jean Jacques Vanden Eynde、Florence Delfosse、Pascal Lor、Yves Van Haverbeke
DOI:10.1016/0040-4020(95)00252-4
日期:1995.5
2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) catalyzes the preparation of N-tetrahydropyranylbenzazoles, 2-substituted 1,3-diphenylimidazolidines, and N-(arylmethylene)benzene-1,2-diamines. In the latter case, use of one equivalent of DDQ provides a novel one-pot method for the synthesis of 1H-benzimidazoles.
glucose solution as reaction medium and catalyst underone-pot oxidant-free conditions. The desired products were obtained at 60 °C with good to excellent yields, and the reaction was performed chemoselectively without formation of 1,2-disubstitutedbenzimidazoles. No need for any extra oxidant, simple workup, and use of carbohydrates as fully green promoters are some advantages of the present work
摘要 以1 M葡萄糖溶液为反应介质和催化剂,在一锅无氧化剂条件下,进行了各种邻苯二胺与取代苯甲醛的反应。所需产物在 60 °C 下以良好到极好的收率获得,并且该反应通过化学选择性进行,没有形成 1,2-二取代苯并咪唑。不需要任何额外的氧化剂、简单的后处理以及使用碳水化合物作为完全绿色的促进剂是目前工作的一些优点。
Srivastava, R. G.; Venkataramani, P. S., Synthetic Communications, 1988, vol. 18, # 13, p. 1537 - 1544
作者:Srivastava, R. G.、Venkataramani, P. S.
DOI:——
日期:——
Dehydrogenations Using Benzofuroxan as Oxidant
作者:F. Pätzold、F. Zeuner、Th. Heyer、H.-J. Nielas
DOI:10.1080/00397919208021304
日期:1992.1
2-Arylsubstituted benzimidazoles, quinoxalines, in 3,5-position substituted 2,6-dimethylpyridines, and 1,4-bis(alkylamino)-9,10-anthracenediones are easily prepared under mild conditions by means of benzofuroxan as oxidant. Thus, the preparation of 2-arylbenzimidazoles succeeds in acetonitrile at 50-degrees-C in yields of 65 to 78 %.