Ruthenium-catalysed synthesis of 2- and 3-substituted quinolines from anilines and 1,3-diols
作者:Rune Nygaard Monrad、Robert Madsen
DOI:10.1039/c0ob00676a
日期:——
as well as naphthylamines were shown to participate in the heterocyclisation. In the 1,3-diol a substituent was allowed in the 1- or the 2-position giving rise to 2- and 3-substituted quinolines, respectively. The best results were obtained with 2-alkyl substituted 1,3-diols to afford 3-alkylquinolines. The mechanism is believed to involve dehydrogenation of the 1,3-diol to the 3-hydroxyaldehyde which
通过苯胺与1,3-二醇的环缩反应描述了取代喹啉的直接合成。反应进行均三甲苯催化量的RuCl 3 ·xH 2 O的溶液,PBu 3和MgBr 2 ·OEt 2。该转化不需要任何化学计量的添加剂,仅产生水 和 二氢作为副产品。含有甲基,甲氧基和氯取代基的苯胺以及萘胺被证明参与了杂环化反应。在里面1,3-二醇在1-或2-位上允许取代基,分别产生2-和3-取代的喹啉。用2-烷基取代的1,3-二醇获得最好的结果,得到3-烷基喹啉。据信该机理涉及对苯酚的脱氢。1,3-二醇 到 3-羟醛 消除了 水生成相应的α,β-不饱和醛 后者然后以类似于多布纳-冯·米勒(Doebner–von Miller)中观察到的方式与苯胺反应喹啉 合成。