Cycloaddition Reaction of 2-Azadienes Derived from β-Amino Acids with Electron-Rich and Electron-Deficient Alkenes and Carbonyl Compounds. Synthesis of Pyridine and 1,3-Oxazine Derivatives
作者:Francisco Palacios、Esther Herrán、Gloria Rubiales、Jose María Ezpeleta
DOI:10.1021/jo016273+
日期:2002.4.1
Functionalized keto-enamines 6 were obtained by nucleophilic addition of enol ethers to the imine moiety of 2-azadienes derived from dehydroaspartic esters 4. Reactions of 2-azadiene 4c containing three electron-withdrawing substituents (CO(2)R) with enol ethers 5 in the presence of lithium perchlorate led to the formation of tetrahydropyridine derivatives 7 in a regio- and stereoselective fashion
通过将烯醇醚亲核加成于衍生自脱氢天冬氨酸酯4的2-氮杂二烯的亚胺部分,可以得到官能化的酮-烯胺6。含有三个吸电子取代基(CO(2)R)的2-氮杂二烯4c与烯醇醚5的反应在高氯酸锂存在下,以区域和立体选择性方式形成四氢吡啶衍生物7。2H- [1,3]-恶嗪10和吡啶衍生物12和13通过含两个吸电子取代基(4-O(2)NC(6)H(4)的贫电子氮杂二烯4d-g的杂环加成反应获得,CO(2)R)在位置1和4与羰基衍生物(乙二醛酸乙酯9a和酮戊二酸二乙酯9b)和缺电子的烯烃四氰基乙烯11。