Suryavanshi Padmakar A, Sridharan Vellaisamy, Maiti Swarupananda, Menéndez J Carlos
Departmento de Química Orgánica y Farmacéutica, Facultad de Farmacia, Universidad Complutense, Plaza de Ramón y Cajal sn, 28040 Madrid (Spain), Fax: (+34) 91-3941822.
Chemistry. 2014 Jul 7;20(28):8791-9. doi: 10.1002/chem.201402607. Epub 2014 Jun 6.
The cerium(IV) ammonium nitrate (CAN)-catalyzed, three-component reaction between primary amines, β-dicarbonyl compounds, and α,β-unsaturated aldehydes in ethanol heated to reflux, constitutes a general, one-pot synthesis of 1,4-dihydropyridines. Their reduction with sodium triacetoxyborohydride furnished piperidine derivatives bearing up to five substituents with full diastereoselectivity in a hitherto inaccessible stereochemical arrangement. The reaction proceeded with no significant loss of enantiomeric purity under mild reduction conditions that are compatible with several functional groups that are normally sensitive to reduction. Octahydroquinolin-5-one derivatives, which were prepared by a modified version of the initial multicomponent reaction, were not suitable substrates for the sodium triacetoxyborohydride mediated reduction, but they were transformed into the corresponding decahydroquinolines, including a precursor of the amphibian alkaloid pumiliotoxin C, by catalytic hydrogenation under a variety of conditions.
在加热至回流的乙醇中，硝酸铈铵（CAN）催化伯胺、β - 二羰基化合物和α,β - 不饱和醛之间的三组分反应，构成了一种通用的、一锅法合成1,4 - 二氢吡啶的方法。用三乙酰氧基硼氢化钠还原它们，以迄今难以获得的立体化学排列，全非对映选择性地提供了带有多达五个取代基的哌啶衍生物。在与几种通常对还原敏感的官能团相容的温和还原条件下，反应进行时对映体纯度没有明显损失。通过初始多组分反应的改进版本制备的八氢喹啉 - 5 - 酮衍生物，不是三乙酰氧基硼氢化钠介导还原的合适底物，但在各种条件下通过催化氢化将它们转化为相应的十氢喹啉，包括两栖动物生物碱 pumiliotoxin C的前体。
