[4+2] Cycloaddition of 2-Substituted 1,2-Dihydropyridines with Nitrosobenzene: Asymmetric Synthesis of <i>trans</i>-2-Substituted 3-Amino-1,2,3,6-tetrahydropyridines
作者:Alexandre Lemire、Daniel Beaudoin、Michel Grenon、André B. Charette
DOI:10.1021/jo048216x
日期:2005.3.1
The preparation of these 3-aminopiperidines is achieved by cycloaddition of nitrosobenzene with 2-substituted 1,2-dihydropyridines followed by chemoselective reduction of the cycloadducts. Enantioenriched 1,2-dihydropyridine derivatives are easily prepared from pyridine and a chiral amide following a previous report from our laboratories. Moreover, the in situ hydrogenation of these cycloadducts over
报道了一种立体选择性合成反式-2-取代的3-氨基-1,2,3,6-四氢吡啶的新方法。这些3-氨基哌啶的制备是通过将亚硝基苯与2-取代的1,2-二氢吡啶环加成,然后对环加合物进行化学选择性还原而实现的。根据我们实验室的先前报告,可以很容易地从吡啶和手性酰胺中制备对映体富集的1,2-二氢吡啶衍生物。此外,这些环加合物在钯在氯化氢的甲醇溶液中在钯上的原位氢化导致四氢吡咯并咪唑。