Superacid activation of
N-SCF
3 sulfenamide reagents generates diprotonated superelectrophilic species for the trifluoromethylthiolation of aromatic amines, as shown by T. Billard, S. Thibaudeau, and co-workers in their Communication on
page 173 ff. This method can be used for the late-stage functionalization of complex biomolecules such as alkaloids and steroids.