Synthesis of Luminescent Fused Imidazole Bicyclic Acetic Esters by a Multicomponent Palladium Iodide‐Catalyzed Oxidative Alkoxycarbonylation Approach
作者:Lucia Veltri、Tommaso Prestia、Patrizio Russo、Catia Clementi、Paola Vitale、Fausto Ortica、Bartolo Gabriele
DOI:10.1002/cctc.202001693
日期:2021.2.5
derivatives, carried out under oxidative conditions using a simple catalytic system consisting of PdI2 (1 mol%) in conjunction with KI (1 equiv.), in the presence of AcONa as additive (1 equiv.) at 100 °C under 20 bar of a 4 : 1 mixture CO‐air. Under the optimized conditions, several N‐(prop‐2‐yn‐1‐yl)pyridin‐2‐amines were smoothly converted into alkyl 2‐(imidazo[1,2‐a]pyridin‐3‐yl)acetates in fair yields
介绍了一种重要的稠合咪唑双环乙酸酯的新的多组分催化方法,该方法的核心存在于许多生物活性成分中。它基于容易获得的N-杂环炔丙基胺衍生物的顺序环化-烷氧基羰基化-异构化反应,该反应是在氧化条件下,使用由PdI 2(1 mol%)和KI(1当量)组成的简单催化体系,在在20°C的4:1混合CO-空气中于100°C下存在AcONa作为添加剂(1当量)。在优化的条件下,数个N-(prop-2-yn-1-基)吡啶-2-胺被平稳地转化为烷基2-(咪唑[1,2- a]] pyridin-3-yl)acetate获得适当收率(51–77%)。该方法也适用于转化ñ - (丙-2-炔-1-基)嘧啶-2-胺成2-(咪唑并[1,2一]嘧啶-3-基)乙酸乙酯和ñ - (丙-2-炔-1-基)吡嗪-2-胺转化为2-(咪唑并[1,2 - a ]吡嗪-3-基)乙酸盐。一些新合成的双环衍生物显示出有希望的发光性质。