使用分子碘作为合成苯并咪唑衍生物的唯一氧化剂,已经实现了分子内芳基CH氨基化反应。通过将芳基胺与相应的腈或芳基碘加成或偶联,可以轻松制备所需的底物。在以碳酸钾(K 2 CO 3)为碱的情况下,这些底物的碘介导的氧化环化作用可提供中等至良好收率的相应产物。此处介绍的无过渡金属协议对空气不敏感,操作简单。这种通用且环保的合成方法学广泛适用于各种N芳基取代的am和吡啶2胺,可直接接触1 H来自相应前体的-苯并[ d ]咪唑和吡啶并[1,2- a ]苯并咪唑衍生物。
DBSA mediated chemoselective synthesis of 2-substituted benzimidazoles in aqueous media
作者:Vikash Kumar、Dipratn G. Khandare、Amrita Chatterjee、Mainak Banerjee
DOI:10.1016/j.tetlet.2013.07.147
日期:2013.10
synthetic method has been developed for the facile synthesis of 2-substituted benzimidazoles in organized aqueousmedia in the presence of a surfactant (viz. DBSA) as catalyst and I2 as co-catalyst. The method described has the advantages of operational simplicity, excellent yields, high chemoselectivity, and clean and green reaction profile.
A simple and efficient procedure for the synthesis of benzimidazoles using air as the oxidant
作者:Songnian Lin、Lihu Yang
DOI:10.1016/j.tetlet.2005.04.101
日期:2005.6
Direct one-step synthesis of various benzimidazoles from phenylenediamines and aldehydes is described using air as the oxidant. The salient features of this method include a simpleprocedure, mild conditions, no coupling agents or commercial oxidants/additives used, no waste produced (only by-product being water), easy purification, and high generality.
Step- and atom-economical synthesis of 2-aryl benzimidazoles via the sulfur-mediated redox condensation between o-nitroanilines and aryl methanols
作者:Huy X. Le、Khoa D. Nguyen、Nam T.S. Phan、Ha V. Le、Tung T. Nguyen
DOI:10.1016/j.tet.2022.132918
日期:2022.8
of expensive and sensivitve substrates such as phenylenediamine and aldehyde or metal catalysts. In this work, 2-nitroanilines and benzylalcohols were alternatively applied for the condensation towards 2-phenyl benzimidazoles in the presence of elemental sulfur and an amine. Mechanistic results proved a dualrole of sulfur as both oxidizing and reducing agents in this synthetic pathway. The study was