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We describe the first thiourea-catalyzed C-F bond activation. The use of a thiourea catalyst and Ti(OiPr)4 as a fluoride scavenger allows the amination of benzylic fluorides to proceed in moderate to excellent yields. Preliminary results with S- and O-based nucleophiles are also presented. DFT calculations reveal the importance of hydrogen bonds between the catalyst and the fluorine atom of the substrate to lower the activation energy during the transition state.

Herein, we report a highly regioselective gold-catalyzed formal hydration of propargylic gem-difluorides. Not only does this transformation provide access to versatile fluorinated building blocks that were difficult or hardly possible to access beforehand, but it also represents a rare case of a highly regioselective gold-catalyzed hydroalkoxylation of internal alkynes and puts forward the utility of the difluoromethylene unit as a directing group in catalysis.

Substituted alkenyl aryl tetrafluoro-λ(6) -sulfanes have been prepared by the direct addition of readily accessible chlorotetrafluorosulfanyl arenes to primary alkynes. Substitution of an apical fluorine of the pentafluorosulfanyl group enables modulation of the reactivity of this little explored functional group while at the same time facilitating the direct investigation of aryl substituent effects on the aryl tetrafluorosulfanyl-substituted products.

The diastereotopic nature of geminal protons γ to the pentafluorosulfanyl (SF 5 ) group was investigated by computational modeling and experimental methods. 1D and 2D NMR techniques were employed to determine the vicinal coupling constants used in the estimation of H C C H dihedral angles required for the approximation of the average solution conformation of SF 5 -substituted alkyl chains. Rotational energy barriers were calculated at the B3LYP/6-31++G (d,p) level in an effort to assess the relative steric demand of the SF 5 group relative to a trifluoromethyl or tert -butyl group. The observed diastereotopicity is likely a result of hindered molecular rotation where one of the γ protons is trapped between two equatorial fluorines of the SF 5 group.

A facile preparation of aliphatic 2-pentafluorosulfanyl aldehydes is described. To investigate the utility of the aldehydes as synthetic building blocks, various transformations of the aldehydes were explored. The pentafluorosulfanyl group was stable under a variety of reaction conditions, and the pentafluorosulfanylated products were obtained in moderate to good yields in most cases.