(±)-2-alkyl-1,2,3,4-tetrahydroquinoline-3-carboxylic esters by a catalyst and pressure dependent tandem reduction-reductive amination reaction
作者:Richard A. Bunce、Takahiro Nago、Nathan Sonobe
DOI:10.1002/jhet.5570440513
日期:2007.9
A series of 2-(2-nitrobenzyl)-substituted β-keto ester derivatives has been subjected to reductive cyclization under catalytic hydrogenation conditions. The reactions were found to be highly dependent on the catalyst and hydrogen pressure used. Hydrogenation over 5% palladium-on-carbon at 4 atmospheres pressure produced complex mixtures of products that included predominantly 1,2,3,4-tetrahydroquinoline
在催化加氢条件下,将一系列2-(2-硝基苄基)-取代的β-酮酯衍生物进行还原环化。发现反应高度依赖于所使用的催化剂和氢气压力。在4个大气压下用5%的钯碳进行氢化,生成的产品复杂混合物,主要包括1,2,3,4-四氢喹啉和喹啉产品;在1个大气压下,相同的反应得到主要含有四氢喹啉和1,4-二氢喹啉衍生物的混合物。使用5%的碳载铂氢化反应更清洁,并提供了所需的顺式和反式-(±)-2-烷基-1,2,3,4-四氢喹啉-3-羧酸酯,其中顺式产物主要为≥13:1。