A Practical Synthesis of N‐aryl/N‐alkyl 4‐Pyridones under Continuous Flow Technology

Abstract

In this report, a practical synthetic approach to access N-aryl/N-alkyl 4-pyridones via a two-step continuous flow process has been developed. In comparison to batch conditions, this [3 + 2 + 1] cycloaddition involving a threecomponents cascade reaction of aniline, dialkyl ethoxymethyl enemalonate and dialkyl acetylenedicarboxylate under mild conditions, which can provide N-aryl/N-alkyl 4-pyridone derivatives with a wider substrate scope and good to excellent yields.

A Practical Synthesis of (Z)-N-Vinyl Substituted N,O-Acetals under Continuous Flow Technology

“…[5] Furthermore, advances in the translation from ''batch'' to continuous ''flow'' mode have expanded rapidly, offering valuable opportunities for a variety of research areas including the handling and scaling of hazardous reactions, [6] and the safe introduction of gases. [7] To continue our interest in continuous flow synthesis, [8] we herein developed a novel, efficient and practical route to the preparation of (Z)-N-vinyl fivemembered cyclic N,O-acetals utilized by continuous flow technology, providing a series of structurally diverse nitrogen-and oxygen-containing heterocycles with high atom economy (Scheme 1c). Furthermore, the flow synthesis technology can be more accurate control of the reaction process and reduced side reactions between two components.…”

Highly Selective Synthesis of (Z)-N-vinyl Ring N,O-Acetal Derivatives by Multi-component Continuous Flow

“…与传统的试管反应相比, 它具有对反应条 件优异的控制功能、高表面积体积比和高效热交换、有 效混合、减少反应时间等优点. 基于本课题组 [7] 运用连 续流动技术构建含氮杂环分子的研究基础, 我们设想借 助连续流动合成技术的优势, 精准调控邻羟基苄胺与醛 反应形成席夫碱中间体, 然后将生成的席夫碱及时排出 与丁炔二酸二烷基酯在碱条件下经历 oxa-Michael 加成 反应, 并发生分子内重排反应, 以高选择性、高收率得 到一系列环 基于上述实验结果和文献报道 [3a,8] , 我们推测的反 应机理如下(图式 3).…”