Palladium-Catalyzed Decarboxylative Alkynylation of α-Acyloxyketones by C(sp3)?O Bond Cleavage

Palladium-catalyzed decarboxylative alkynylation of α-acyloxyketones triggered by C(sp³)?O bond cleavage is disclosed. The decarboxylation strategy featuring a neutral reaction condition enabled an unprecedent catalytic alkynylation of a ketone enolate. The reaction was applied to a variety of substrates, giving desired products in good yields. We successfully obtained X-ray crystallography of a new palladium–enolate intermediate that was synthesized by a reaction of Pd(cod)(CH₂TMS)₂] with XPhos and α-acyloxyketone at room temperature, indicating facile C(sp³)?O bond disconnection.