Negishi Cross-Coupling Reactions Catalyzed by an Aminophosphine-Based Nickel System: A Reliable and General Applicable Reaction Protocol for the High-Yielding Synthesis of Biaryls
作者:Roman Gerber、Christian M. Frech
DOI:10.1002/chem.201101037
日期:2011.10.10
05 equiv), dissolved in THF, in air at 25 °C forms a highly active catalytic system for the cross‐coupling of a large variety of electronically activated, non‐activated, deactivated, and ortho‐substituted, heterocyclic, and functionalized aryl bromides and aryl chlorides with diarylzinc reagents. Very high levels of conversion and yields were obtained within 2 h at 60 °C in the presence of only 0.1 mol % of
在25°C的空气中,用溶于THF的1,1',1''-(膦三基)三哌啶(≈2.05当量)处理NiCl 2的NMP溶液,形成高活性的催化体系,用于交叉偶联多种电子激活,未激活,停用和正交用二芳基锌试剂取代,杂环和功能化的芳基溴化物和芳基氯化物。在仅0.1 mol%催化剂(基于镍)的存在下,于60°C在2 h内即可获得非常高的转化率和产率,因此催化剂负载量远低于Negishi反应的镍催化形式的典型报道。各种可能含有三氟甲基,氟化物或其他官能团的芳基卤化物,例如乙缩醛,酮,醚,酯,内酯,酰胺,亚胺,苯胺,烯烃,吡啶,喹啉和嘧啶,已成功转化为相应的联芳基。在两个反应伙伴中都可以接受电子和空间变化。实验观察表明,分子(Ni I / Ni III)机制有效。