Palladium-catalyzed C(sp2)-H alkylation of aldehyde-derived hydrazones with functionalized difluoromethyl bromides
Résumé
A palladium-catalyzed C(sp2)−H difluoromethylation of aldehyde-derived hydrazones using bromodifluoromethylated compounds to afford the corresponding functionalized difluoromethylketone hydrazones has been established. It is proposed that a radical/SET mechanism proceeding via a difluoroalkyl radical may be involved in the catalytic cycle. Applications of the methodology to the synthesis of α,α-difluoro-β-ketoesters and α,α-difluoroketones (RCOCF2H) have been illustrated.