Synthesis of Biheterocycles Based on Quinolinone, Chromone, and Coumarin Scaffolds by Palladium-Catalyzed Decarboxylative Couplings.

An efficient Pd-catalyzed decarboxylative coupling of heterocyclic carboxylic acids with heterocyclic halides to achieve the synthesis of biheterocycles of biological interest has been reported. In all cases, the cross-coupling reactions take place rapidly in DMSO in good yields and efficiently proceed in the presence of a PdBr2/DPEphos catalytic system, furnishing the novel biheterocycles based on quinolin-4-one, quinolin-2-one, chromone, and coumarin scaffolds.