Organocatalytic C(sp3)-H Functionalization of 5-Methyl-2,3-dihydrofuran Derivatives with Trifluoropyruvates via a Sequential exo-Tautomerization/Carbonyl-Ene Process.

An organocatalytic C(sp3)-H functionalization of 5-methyl-2,3-dihydrofuran derivatives with trifluoropyruvates was achieved via a sequential exo-tautomerization/carbonyl-ene process, providing the biologically important CF3-substituted 2,3-dihydrofurans in high yields. This method featured mild metal-free conditions, good chemoselectivity, and easy scalability.