Nucleophilic di- and tetrafluorination of dicarbonyl compounds

Reactions of various diketo compounds with Deoxofluor [(CH3OCH2CH2)(2)NSF3] have been investigated. When reacted with Deoxofluor, a-diketones, R1COCOR2 (R-1 = R-2 = Ph; R-1 = R-2 = 4-Me-C6H4; R-1 = Ph, R-2 = Me; R-1 = Me, R-2 = Et) (1a-d) formed difluoro derivatives (2a-d) in the presence of a catalytic amount of HF and/or tetrafluoro (3a-d) products depending on the reaction conditions and stoichiometry used. Reactions of beta -diketones, R3COCH2COR4 (R-3 = R-4 = Ph; R-3 = R-4 = Me; R-3 = Me, R-4 = Ph) (4e-g), with Deoxofluor in the presence of a catalytic amount of HF led to the formation of difluoroalkenones as a mixture of E (5e-g) and Z (6e-g) isomers in good yield. Reaction of other diones, R5CO-X-COR6 (R-5 = R-6 = Ph, X =-CH=CH-; R-5 = R-6 = Me, X = -C6H4C6H4-; R-5 = R-6 = Ph, X = -CH2CH2CH2-; R-5 = R-6 = Me, X = -CH2CH2-) (7h-k) with Deoxofluor produced mainly difluoro products (8h-k) with low yields of tertrafluoro derivatives (9h-k). Acyclic alpha -keto amides react poorly to give the corresponding difluoro derivatives, whereas cyclic (alpha -keto amides (101-p) react smoothly under very mild conditions to produce the corresponding difluoro products (111-p) in > 88% isolated yield.