Pd/C-Catalyzed coupling and cyclization of β-bromo-α,β-unsaturated carboxylic acids with terminal alkynes leading to alkylidenefuranones

Palladium-catalyzed coupling of β-bromo-α,β-unsaturated carboxylic acids with terminal alkynes and subsequent regioselective 5-exo-dig cyclization produces (Z)-alkylidenefuranones in good yields.

Graphical abstract-Bromo--unsaturated carboxylic acids are coupled and cyclized with terminal alkynes in the presence of a palladium catalyst to afford (Z)-alkylidenefuranones.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Pd/C catalyzes Sonogashira-coupling followed by cyclization. ► Coupling between β-bromo-α,β-unsaturated carboxylic acids and terminal alkynes. ► Regioselective 5-exo-dig cyclization of β-alkynyl-α,β-unsaturated carboxylic acids. ► A new route for (Z)-alkylidenefuranones from readily available starting ketones.