PdII catalyzed ligand controlled synthesis of bis(3-furanyl)methanones and methyl 3-furancarboxylates

The PdII catalyzed carbonylation of allenyl ketones has been investigated. Carbonylative dimerization predominantly proceeded to afford bis(3-furanyl)methanones 2 as the major products. The use of DMSO strikingly changed the course of the reaction, affording methyl 3-furancarboxylates 3 as the major products. DFT calculations revealed that DMSO stabilized the methanol coordinated intermediate, leading to methoxycarbonylation. Substituted furans 2 and 3 were selectively synthesized from the same allenyl ketone substrate.