A zinc(II) triflate catalyzed three component synthesis of 1,6-dihydropyridines, involving aldimines, alkynes and electron-deficient dimethyl acetylenedicarboxylate (DMAD), in good to excellent yields has been described. Besides a range of different N-substituents, a variety of both aromatic and aliphatic alkynes could be used. The application of electron-deficient propiolates instead of DMAD resulted in regiospecific incorporation of the ester functionality on the 1,6-dihydropyridine ring. The reaction proceeds via a cascade reaction involving nucleophilic addition of the metal acetylide to the imine, followed by the addition of the intermediately formed propargylic amine to the electron-deficient alkyne and subsequent 6-endo dig cyclization.

中文翻译：

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高度官能化1,6-二氢吡啶类化合物的合成通过在锌（OTF）₂醛亚胺的催化的三组分级联反应和两个炔烃（IA ² -耦合）†

已经描述了三氟甲磺酸锌（II）催化1，6-二氢吡啶的三组分合成，涉及醛亚胺，炔烃和电子缺陷的乙炔基二羧酸二甲酯（DMAD），收率良好至优异。除了一系列不同的N-取代基之外，还可以使用多种芳族和脂族炔烃。缺电子的丙酸酯代替DMAD的应用导致在1,6-二氢吡啶环上酯官能团的区域特异性结合。该反应通过级联反应进行，该级联反应包括将乙炔金属亲核加成到亚胺中，然后将中间形成的炔丙基胺加到缺电子的炔烃中，然后进行6-内挖。 环化。