Copper-Catalyzed 1,1-Alkylmonofluoro­alkylation of Terminal Alkynes with Diazo Compounds and 2‑Fluoro-1,3-dicarbonyl Compounds: Access toward (E)‑β-Monofluoroalkyl-β,γ-unsaturated Esters or Ketones

An efficient copper-catalyzed three-component 1,1-alkylmonofluoro­alkylation of terminal alkynes, diazo compounds, and 2-fluoro-1,3-dicarbonyl compounds for the synthesis of (E)-β-monofluoro­alkyl-β,γ-unsaturated esters or ketones has been developed. The methodology features a broad substrate scope, an inexpensive and easily available catalytic system, and excellent selectivity with good yields. The mechanism of the tandem Cu-catalyzed cross-coupling and nucleophilic addition of allenes has been investigated.