Palladium-Catalyzed Site-Selective Fluorination of Unactivated C(sp3)-H Bonds

The transition-metal-catalyzed direct C-H bond fluorination is an attractive synthetic tool toward the preparation of organofluorines. While many methods exist for the direct sp(3) C-H functionalization, site-selective fluorination of unactivated sp(3) carbons remains a challenge. Direct, highly site-selective and diastereoselective fluorination of aliphatic amides via a palladium-catalyzed bidentate ligand-directed C-H bond functionalization process on unactivated sp3 carbons is reported. With this approach, a wide variety of beta-fluorinated amino acid derivatives and aliphatic amides, important motifs in medicinal and agricultural chemistry, were prepared with palladium acetate as the catalyst and Selectfluor as the fluorine source.