Jiang Chunhui, Chen Yayun, Zhang Hongkui, Tan Jian-Ping, Wang Tianli
School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, 212003, P. R. China.
Key Laboratory of Green Chemistry&Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China.
Chem Asian J. 2019 Sep 2;14(17):2938-2944. doi: 10.1002/asia.201900641. Epub 2019 Aug 7.
A catalyst-free decarboxylative reaction between β-keto acids and 2H-chromene acetals in water was developed. This reaction featured a broad substrate scope and easily obtainable starting materials to afford α-functionalized 2H-chromenes in high yields. The synthetic value of this protocol was also demonstrated by the scale-up synthesis and versatile conversions of the title product into other useful compounds. In addition, control experiments indicated that water was essential for the reactivity. Mechanistic studies further revealed that the reaction proceeded through a self-promoted tandem pseudo-substitution and decarboxylation process.
开发了一种在水中β-酮酸与2H-色烯缩醛之间的无催化剂脱羧反应。该反应具有广泛的底物范围和易于获得的起始原料，能够以高产率得到α-官能化的2H-色烯。放大合成以及将标题产物转化为其他有用化合物的多种转化也证明了该方法的合成价值。此外，对照实验表明水对于反应活性至关重要。机理研究进一步揭示该反应通过自促进的串联假取代和脱羧过程进行。
