水相铜/十二烷基取代酰肼-吡啶-N-氧化物催化咪唑的N-芳基化

Copper/Dodecyl Substituted Hydrazide-pyridine-N-oxide Catalyzed N-Arylation of Imidazoles with Aryliodides in Water

设计合成了5种新型烷基取代酰肼-吡啶-N-氧化物,并将其作为水相铜催化含氮杂环与芳香碘代物偶联反应的配体.实验结果表明,十二烷基取代酰肼-吡啶-N-氧化物的催化效果最佳.对影响反应的其它条件,如铜源、碱、反应时间和温度等条件进行了优化,建立了最佳反应条件:CuO(10%,摩尔分数),NaOH(1 mmol),TBAB(5%,摩尔分数),L5(20%,摩尔分数),于120℃反应12 h,无需惰性气体保护.在此条件下,芳香碘代物与咪唑偶联反应的产率为60%~92%.该方法的特点是以水作为反应溶剂,长链烷基取代酰肼-吡啶-N-氧化物同时起到了铜催化剂配体和相转移催化剂的作用.

In this paper, five novel dodecyl-substituted hydrazide-pyridine-N-oxide ligands were designed and synthesized as the ligands and phase-transfer catalyst for the N-arylation reaction of nitrogen-containing heterocycles and aromatic iodides. The catalytic activities of substituted hydrazide-pyridine-N-oxides, copper source, alkali, reaction time and temperature were optimized and the optimum reaction conditions were estab- lished. Under these conditions, the imidazole could be arylated smoothly with various aryl iodides to provide the corresponding products in the yields of 60%--92%. In the reaction, water was used as the reaction solvent and the long chain alkyl-substituted hydrazide-pyridine-N-oxide acts as a copper catalyst ligand and phasetransfer catalyst.