Iodosobenzene Tetrafluoroborate, Hexafluoroantimonate, and Hexafluorophosphate: Stable Electrophilic Hypervalent Iodine Reagents without Nucleophilic Ligands

Three novel iodine(III) derivatives—tetrafluoroborate (1), hexafluoroantimonate (2), and hexafluorophosphate (3)—were prepared by the reaction of (diacetoxyiodo)benzene with aqueous solutions of the corresponding acids. Reactions of these reagents with alkenes (cyclohexene, indene) in the presence of external nucleophiles (methanol, acetic acid, lithium perchlorate) yielded products of vicinal disubstitution. Silyl enol ethers reacted with reagents 1 and 3 to give products of oxidative coupling with high yield. Several alkynyliodonium salts were prepared from 1-pentyne and these reagents.