Transition-Metal-Free Sonogashira-Type Cross-Coupling of Alkynes with Fluoroarenes

A novel, inexpensive, and efficient palladium-, copper-, ligand-, and amine-free Sonogashira-type cross-coupling reaction of terminal alkynes with unreactive aryl fluorides in the presence of sodium, sodium methoxide, and calcium hydroxide under the assistance of a Grignard reagent was developed. A plausible mechanism was also suggested

Copper-Catalyzed Coupling Cyclization of <i>gem</i>-Difluoroalkenes with Activated Methylene Carbonyl Compounds: Facile Domino Access to Polysubstituted Furans

A novel and efficient CuI-catalyzed synthesis of 2,3,5-trisubstituted furans was developed via coupling cyclization of <i>gem</i>-difluoroalkenes with active methylene carbonyl compounds such as 1,3-dicarbonyl compounds, acetoacetonitrile, and phenylsulfonylacetone with the assistance of a base. Commercial availability of substrates or reagents, good to high isolated yields, and excellent functional group compatibility make this transformation a powerful tool for the synthesis of various furans. A plausible mechanism involving the allenyl ketone is suggested

Copper-Catalyzed Coupling Cyclization of <i>gem</i>-Difluoroalkenes with Activated Methylene Carbonyl Compounds: Facile Domino Access to Polysubstituted Furans

A novel and efficient CuI-catalyzed synthesis of 2,3,5-trisubstituted furans was developed via coupling cyclization of <i>gem</i>-difluoroalkenes with active methylene carbonyl compounds such as 1,3-dicarbonyl compounds, acetoacetonitrile, and phenylsulfonylacetone with the assistance of a base. Commercial availability of substrates or reagents, good to high isolated yields, and excellent functional group compatibility make this transformation a powerful tool for the synthesis of various furans. A plausible mechanism involving the allenyl ketone is suggested

Synthesis of <i>N</i>‑(α-Fluorovinyl)azoles by the Reaction of Difluoroalkenes with Azoles

A mild and versatile method for the construction of C–N bonds by the reaction of (2,2-difluorovinyl)­arenes with various N–H-containing heterocycles in the presence of K₃PO₄ has been developed. The reaction proceeded efficiently at room temperature (25 °C) affording the (<i>E</i>)-<i>N</i>-α-fluorovinyl derivatives of azoles <b>3</b> in good to excellent yields with relatively high stereoselectivity