We report a novel and practical one-pot Rh(III)-catalyzed strategy to construct benzimidazo[1,2-a]quinolines from readily available imidamides and anthranils. The cascade reaction proceeds via a C-H amination-cyclization-cyclization process in ionic liquid without any additives and possesses simple operation, moderate-to-high yield, and broad substrate scope features, which will provide the reference
Metal-Free Annulation of Arenes with 2-Aminopyridine Derivatives: The Methyl Group as a Traceless Non-Chelating Directing Group
作者:Srimanta Manna、Kiran Matcha、Andrey P. Antonchick
DOI:10.1002/anie.201403712
日期:2014.7.28
A novel annulation reaction between 2‐aminopyridine derivatives and arenes under metal‐free conditions is described. The presented intermolecular transformation provided straightforward access to the important pyrido[1,2‐a]benzimidazole scaffold under mild reaction conditions. The unprecedented application of the methylgroup of methylbenzenes as a traceless, non‐chelating, and highly regioselective
描述了在无金属条件下2-氨基吡啶衍生物和芳烃之间的新型环化反应。提出的分子间转化提供了在温和的反应条件下直接进入重要的吡啶并[1,2- a ]苯并咪唑支架的途径。据报道,甲基苯的甲基作为无痕,非螯合和高度区域选择性的导向基团得到了空前的应用。
Novel Strategy for Synthesis of Substituted Benzimidazo[1,2-<i>a</i>]quinolines
An efficient method for the synthesis of benzimidazo[1,2-a]quinolines under transition-metal-free conditions has been developed through a cascade reaction involving sequential aromatic nucleophilic substitution and intramolecular Knoevenagel condensation reactions. This method is applicable for the synthesis of a wide range of benzimidazo[1,2-a]quinoline derivatives from readily available 2-fluoroarylaldehyde and benzimidazole substrates.