Cyclization–carbonylation–cyclization coupling reaction of γ-propynyl-1,3-diketones with palladium(II)-bisoxazoline catalyst

Cyclization–carbonylation–cyclization coupling reaction (CCC-coupling reaction) of γ-propynyl-1,3-diketones catalyzed by (box)PdII complexes afforded symmetrical ketones bearing two oxabicyclic groups in moderate to excellent yields.