Palladium-Catalyzed C–H Benzannulation of Functionalized Furans and Pyrroles with Alkynes
作者:Jia Seo、Che-Wei Chen、Shih-Ching Chuang、Jung Min Joo、Woohyeong Lee、Ju Eun Jeon、Pei-Ling Chen
DOI:10.1055/a-1502-3641
日期:2021.9
A benzannulation strategy involving activation of two C–H bonds of five-membered heteroarenes was developed. Readily available furans and pyrroles stabilized by synthetically useful electron-withdrawing groups underwent Pd-catalyzed 1:2 annulation reactions with diaryl alkynes. A variety of functional groups, including ester, amide, ketone, aldehyde, and nitrile, on the heterocyclic cores were tolerated
开发了一种涉及激活五元杂芳烃的两个 C-H 键的苯环化策略。通过合成有用的吸电子基团稳定的容易获得的呋喃和吡咯与二芳基炔进行 Pd 催化的 1:2 环化反应。在 Pd 催化的氧化反应中,杂环核上的各种官能团,包括酯、酰胺、酮、醛和腈,都可以耐受。在这些反应中,2,2-二甲基丁酸及其共轭碱的结合促进了杂芳环的金属化和使用氧作为末端氧化剂的 Pd(0) 物质的再氧化。该策略提供了荧光苯并呋喃和吲哚衍生物,有望进一步开发功能化的多环杂芳族化合物。