Transition-Metal-Free Transfer Hydrogenative Cascade Reaction of Nitroarenes with Amines/Alcohols: Redox-Economical Access to Benzimidazoles
作者:Arup K. Kabi、Raghuram Gujjarappa、Anupam Roy、Abhishek Sahoo、Dulal Musib、Nagaraju Vodnala、Virender Singh、Chandi C. Malakar
DOI:10.1021/acs.joc.1c01450
日期:2021.11.5
describes an efficient transition-metal-free process toward the transfer hydrogenative cascade reaction between nitroarenes and amines or alcohols. The developed redox-economical approach was realized using a combination of KOtBu and Et3SiH as reagents, which allows the synthesis of benzimidazole derivatives via σ-bond metathesis. The reaction conditions hold well over a wide range of substrates embedded with
该报告描述了一种有效的无过渡金属工艺,用于硝基芳烃与胺或醇之间的转移氢化级联反应。开发的氧化还原经济方法是使用 KO t Bu 和 Et 3 SiH 作为试剂的组合实现的,这允许通过 σ 键复分解合成苯并咪唑衍生物。反应条件适用于各种嵌入不同官能团的底物,以良好至优异的产率提供所需的产品。已根据一系列控制实验、质谱证据描述了机械建议,这些证据得到了具有可行能量分布的密度泛函理论 (DFT) 计算的充分支持。
An Efficient Synthesis of 2-Substituted Benzimidazoles via Photocatalytic Condensation of <i>o</i>-Phenylenediamines and Aldehydes
作者:Jeshma Kovvuri、Burri Nagaraju、Ahmed Kamal、Ajay K. Srivastava
DOI:10.1021/acscombsci.6b00107
日期:2016.10.10
method has been developed for the efficient synthesis of functionalized benzimidazoles. This protocol involves photocatalytic condensation of o-phenylenediamines with various aldehydes using the Rose Bengal as photocatalyst. The method was found to be general and was successfully employed for accessing pharmaceutically important benzimidazoles by the condensation of aromatic, heteroaromatic and aliphatic
A novel and efficient approach to the synthesis of 2‐substituted benzimidazoles has been developed via CuI/DMEDA‐catalyzed coupling reaction and post‐cyclization with glacial acetic acid from readily available 2‐iodoanilines and amides. This method is suitable for the construction of a variety of benzimidazoles in moderate to good yields under short reaction times.
operationally simple and user-friendly one-pot domino protocol for the synthesis of 2-aryl/hetaryl benzimidazoles has been devised from easily available and inexpensive 1,2-phenylenediamines and βoxodithioesters. The strategic [4+1] heteroannulation initiated by Brønsted acid PTSA relies on remarkable domino sequence of condensation, cyclization, and elimination. The current approach enables N-H/N-H functionalization
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.