Ruthenium-catalysed synthesis of 2-and 3-substituted quinolines from anilines and 1,3-diols
Ruthenium-catalysed synthesis of 2-and 3-substituted quinolines from anilines and 1,3-diols
复制标题
DOI：
10.1039/c0ob00676a
复制
发表时间：
2011-01-01
影响因子：
3.2
通讯作者：
Madsen, Robert
中科院分区：
文献类型：
--
作者：
Monrad, Rune Nygaard;Madsen, Robert
通过苯胺与1，3-二醇的环合反应直接合成了取代喹啉类化合物。反应在均三甲苯溶液中进行，催化量为RuCl3中心点XH(2)O、PBu3和MgBr2中心点OEt2。这种转化不需要任何化学计量添加剂，只产生水和氢气作为副产品。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1，3-二醇中，1-或2-位允许取代基，分别产生2-取代喹啉和3-取代喹啉。以2-烷基取代的1，3-二醇合成3-烷基喹啉的效果最好。其机理被认为涉及1，3-二醇脱氢为3-羟基醛，从而将水消除为相应的α，β-不饱和醛。然后，后者与苯胺的反应方式与Doebner-von Miller喹啉合成中观察到的类似。
A straightforward synthesis of substituted quinolines is described by cyclocondensation of anilines with 1,3-diols. The reaction proceeds in mesitylene solution with catalytic amounts of RuCl3 center dot xH(2)O, PBu3 and MgBr2 center dot OEt2. The transformation does not require any stoichiometric additives and only produces water and dihydrogen as byproducts. Anilines containing methyl, methoxy and chloro substituents 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 eliminates water to the corresponding alpha,beta-unsaturated aldehyde. The latter then reacts with anilines in a similar fashion as observed in the Doebner-von Miller quinoline synthesis.