3-Trifluoromethylated Coumarins and Carbostyrils by Radical Trifluoromethylation of ortho-Functionalized Cinnamic Esters

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• 作者：Slim Chaabouni ; Florent Simonet ; Alison Franç ; ois ; Souhir Abid ; Chantal Galaup and Stefan Chassaing
• 刊名：European Journal of Organic Chemistry
• 出版年：2017
• 出版时间：January 10, 2017
• 年：2017
• 卷：2017
• 期：2
• 页码：271-277
• 全文大小：1352K
• ISSN：1099-0690

文摘

A method for the trifluoromethylation of ortho-hydroxycinnamic esters was developed to achieve the regioselective synthesis of 3-trifluoromethylated coumarins. The reaction was performed by using the Togni reagent as the CF₃ source under mild conditions and showed good functional- group tolerance. The scope of this copper-mediated method was further expanded to the synthesis of 3-trifluoromethylated carbostyrils starting from ortho-aminocinnamic derivatives. Interestingly, a sequential one-pot synthesis of 3-trifluoromethylated coumarins starting from salicylaldehydes was further developed. The mechanism of this cascade reaction was explored, and a radical pathway was found to be consistent with the obtained results.