Synthesis of 2,2-diaryl-1,1-difluoroethenes via Pd-catalyzed dehydrosulfonylative cross-coupling of α-[difluoro(phenylsulfonyl)methyl]benzyl tosylates with arylboronic acids

Article abstract of DOI:10.1016/j.tet.2018.04.054

By using PhSO₂CF₂H as the difluoromethylidene equivalent, a novel method for connecting aromatic aldehydes and arylboronic acids via consecutive reactions was developed to obtain structurally diverse 2,2-diaryl-1,1-difluoroethenes. The key step is the palladium-catalyzed dehydrosulfonylative cross-coupling of tosylates that are prepared from PhSO₂CF₂H, aromatic aldehydes and tosyl chloride. Mechanistic investigations showed that the reaction proceeds mainly through base-mediated dehydrosulfonylation followed by palladium-catalyzed C(sp²)-C(sp²) cross-coupling reaction.