Newelectrophilic fluoroalkylating agents based on the sulfoximine skeleton as a common platform are described. We demonstrate the importance of the activating group, attached to the nitrogen, and its specificity for the fluorinated group to be delivered. As an application, a variety of unknown dichlorofluoro, bromodifluoro, and trifluoromethyl alkynes have been prepared using these reagents.
A series of unsymmetrical S-(bromodifluoromethyl)diarylsulfonium salts 1 were readily synthesized by treatment of corresponding (bromodifluoromethyl)arylsulfoxides 2 and substituted benzenes 3 with triflic anhydride in moderate to good yields. The unsymmetrical sulfonium salts 1 with different aryl groups having electron-donating or electron-withdrawing substituents can be nicely constructed depending on the choice of 2 and 3. Bromodifluoromethylation of alkynes was evaluated by using the selected diarylsulfonium salts 1 to provide the desired bromodifluoromethylated alkynes in moderate to good yields.