Synthesis of 1,2-Dihydropyridines Using Vinyloxiranes as Masked Dienolates in Imino-Aldol Reactions
作者:Bernhard Brunner、Nicole Stogaitis、Mark Lautens
DOI:10.1021/ol061086p
日期:2006.8.1
application of vinyloxiranes, substituted with an electron-withdrawing group, as masked dienolates in vinylogous imino-aldol reactions was achieved. Under the reaction conditions highly substituted 1,2-dihydropyridines were obtained in moderate to good yields. Mechanistic studies indicate that the reaction proceeds via the formation of an (E)-amino-alpha,beta-unsaturated aldehyde, followed by isomerization
[反应:见正文]已实现了用吸电子基团取代的乙烯基环氧乙烷作为掩蔽的二烯酸酯在乙烯基亚氨基羟醛反应中的应用。在反应条件下,以中等至良好的产率获得了高度取代的1,2-二氢吡啶。机理研究表明,该反应通过形成(E)-氨基-α,β-不饱和醛,然后异构化为(Z)-异构体,环化并消除水分子而进行,从而导致生成1,2-二氢吡啶。