Base-Promoted Annulative Difluoromethylenation of Enaminones with BrCF2CO2Et toward 2,2-Difluorinated 2,3-Dihydrofurans
Jinbiao Ying, Ting Liu, Yunyun Liu* and Jie-Ping Wan*
*College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, P. R. China, Email: chemliuyunyunjxnu.edu.cn, wanjiepingjxnu.edu.cn
J. Ying, T. Liu, Y. Liu, J.-P. Wan, Org. Lett., 2022, 24, 2393-2398.
A [4 + 1] annulation of enaminones and BrCF2CO2Et enables a practical synthesis of 2,2-difluorinated 2,3-dihydrofurans in the presence of Na2CO3. A subsequent reaction with hydrochloric acid provides β-keto enoic acids (4-oxo-2-butenoic acids).
see article for more examples