Electrophilic Triflyl-arylation and Triflyl-pyridylation by Unsymmetrical Aryl/Pyridyl-λ3-iodonium Salts: Synthesis of Aryl and Pyridyl Triflones.

Unsymmetrical diaryl-λ3-iodonium salts containing aryl triflone (Ar-SO2CF3) were designed and synthesized. X-ray crystal structure analysis of the salt indicated a T-shaped geometry at the iodine atom. The salts were found to be powerful electrophilic reagents for triflyl-arylation of C-, N-, and O-centered nucleophiles under mild conditions. Electrophilic transfer of pyridine triflone (Py-SO2CF3) to nucleophiles was also realized by the use of corresponding triflylpyridyl-aryl-λ3-iodonium salts. Selection of auxiliaries (dummy ligands) of unsymmetrical diaryl-λ3-iodonium salts is crucial for this transformation.