Four-Component Synthesis of Functionalized 2,2′-Bipyridines Based on the Blaise Reaction
作者:Hans-Ulrich Reissig、Paul Hommes、Phillip Jungk
DOI:10.1055/s-0030-1260304
日期:2011.10
In situ C-acylation of the Blaise intermediate - as reported by Lee and coworkers - provides α-acyl-β-enamino esters that are versatile building blocks for the preparation of N-heterocycles. The corresponding N-acylated β-ketoenamides can be employed in the synthesis of 4-hydroxypyridine derivatives. N-Acylation of the α-acyl-β-enamino esters with 2-picolyl chloride furnished β-ketoenamides, and the
Lee和他的同事报道,Blaise中间体的原位C-酰化作用提供了α-酰基-β-烯氨基酯,这些酯是制备N杂环的通用构建基块。相应的N-酰化的β-酮烯酰胺可用于合成4-羟基吡啶衍生物。α-酰基-β-烯胺酸酯与2-吡啶甲基氯的N-酰化提供了β-酮烯酰胺,随后的TMSOTf /碱促进的分子内缩合反应导致了4-羟基-2,2'-联吡啶衍生物。转化为2,2'-联吡啶-4-基壬酸酯可以实现进一步的功能化,例如钯催化的偶联反应。 缩合-2,2'-联吡啶-β-酮烯酰胺-多组分反应-壬酸酯-吡啶