The reaction of arenediazonium tetrafluoroborates with chlorotrimethylsilane in a tetrahydrofuran/N,N-dimethylformamide (DMF) (5v/3v) solution afforded the protodediazotization products in high yields. The reactions of the diazonium salts with halotrimethylsilanes in DMF were found to give the corresponding haloarenes. Among the halodediazotization reactions, the iododediazotization with iodotrimethylsilane proceeded smoothly at room temperature to give the iodoarenes in excellent yields. In a similar manner, a variety of azidoarenes were obtained in consistently high yields by the treatment of arenediazonium tetrafluoroborates with azidotrimethylsilane in a DMF solution.

ChemInform Abstract Arenediazonium tetrafluoroborates such as (I), which are usually difficult to decompose, undergo either proto-(→ (II)) or halodediazotization (→ (III), (IV), (VI)) depending on the halotrimethylsilane and additive employed. The acceleration effects of the trimethylsilyl compounds on the decomposition of (I) (-N3 > -I > -Br > -Cl) are rationalized on the basis of the HSAB principle.