Metal-Free Decarboxylative Hetero-Diels–Alder Synthesis of 3-Hydroxypyridines: A Rapid Access to <i>N</i>-Fused Bicyclic Hydroxypiperidine Scaffolds
作者:Laurie-Anne Jouanno、Vincent Di Mascio、Vincent Tognetti、Laurent Joubert、Cyrille Sabot、Pierre-Yves Renard
DOI:10.1021/jo402729a
日期:2014.2.7
A complete experimental and theoretical study of the thermally controlled metal-free decarboxylative hetero-Diels–Alder (HDA) reaction of 5-alkoxyoxazoles with acrylic acid is reported. This strategy offers a new entry to valuable 2,6-difunctionalized 3-hydroxypyridines from readily available 2- and 4-disubstituted 5-alkoxyoxazoles. The reaction conditions proved compatible with, among others, ketone
报道了5-烷氧基恶唑与丙烯酸热控制的无金属脱羧杂狄尔斯-阿尔德(HDA)反应的完整实验和理论研究。该策略为易于获得的2-和4-二取代的5-烷氧基恶唑提供了有价值的2,6-二官能化的3-羟基吡啶的新入口。证明该反应条件尤其与酮,酰胺,酯,醚和腈基相容。该方案具有广泛的官能团耐受性,可通过吡啶脱芳构化策略快速而通用地获得羟基吲哚并咪唑和羟基喹oli嗪衍生物。