Palladium‐Catalyzed C(sp2)−H Alkylation of Aldehyde‐Derived Hydrazones with Functionalized Difluoromethyl Bromides. Issue 5 (16th December 2015)

• Record Type: Journal Article
• Authors: Prieto, Alexis; Melot, Romain; Bouyssi, Didier; Monteiro, Nuno
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 5(2016)
• Page Start: 1885
• Page End: 1889
• Publication Date: 2015-12-16
• Subjects: fluorine -- homogeneous catalysis -- hydrazones -- palladium -- reaction mechanisms; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201510334
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: A palladium‐catalyzed C(sp 2 )−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 (RCOCF2 H) have been illustrated. Abstract : Single file : The title reaction was established as a new and versatile synthetic entry to α, α‐difluoro carbonyl compounds. On the basis of preliminary studies, the proposed mechanism involves a radical/single‐electron transfer process via a difluoroalkyl radical intermediate.