Cyclization-carbonylation-cyclization coupling reaction of α,β-alkynic hydrazones with palladium(II)-bisoxazoline catalyst

A cyclization-carbonylation-cyclization coupling reaction (CCC-coupling reaction) of alpha,beta-alkynic hydrazones, catalyzed by (box)Pd-II complexes, afforded symmetrical ketones bearing two pyrazole groups in good to excellent yields. This method is applicable to a broad range of substrates.