Ruthenium(<scp>ii</scp>) complexes with N-heterocyclic carbene–phosphine ligands for the <i>N</i>-alkylation of amines with alcohols
作者:Ming Huang、Yinwu Li、Xiao-Bing Lan、Jiahao Liu、Cunyuan Zhao、Yan Liu、Zhuofeng Ke
DOI:10.1039/d1ob00362c
日期:——
A large variety of (hetero)aromatic amines and primary alcohols were efficiently converted into mono-N-alkylated amines in good to excellent isolated yields. Notably, aliphatic amines, challenging methanol and diamines could also be transformed into the desired products. Detailed control experiments and density functional theory (DFT) calculations provide insights to understand the mechanism and the
金属氢化物配合物是通过借氢/氢自动转移 (BH/HA) 策略将胺与醇进行N-烷基化的关键中间体。金属氢化物配合物的反应性调节可以调节醇的脱氢和亚胺的加氢。在此,我们报道了与杂二齿 N-杂环卡宾 (NHC)-膦配体的钌 ( II ) 配合物,通过杂二齿配体对 [Ru-H] 物种的反应性调节,实现了N-烷基化反应中的智能途径选择。特别是具有苯基翼尖基团和 BArF 的复合物6cb -抗衡阴离子被证明是该转化最有效的预催化剂之一(温度低至 70 °C,整洁的条件和催化剂负载量低至 0.25 mol%)。多种(杂)芳族胺和伯醇以良好至优异的分离产率有效地转化为单-N-烷基化胺。值得注意的是,脂肪胺、具有挑战性的甲醇和二胺也可以转化为所需的产品。详细的控制实验和密度泛函理论 (DFT) 计算为理解该过程中通过[Ru-H] 物种的机制和智能途径选择提供了见解。