Bis(pyridine)iodonium(I) tetrafluoroborate
Bis(pyridine)iodonium(I) tetrafluoroborate is an iodonium salt commonly employed as an electrophilic iodinating reagent in organic synthesis. It is a crystalline solid, typically prepared by reacting iodine with pyridine and tetrafluoroboric acid or a suitable salt of tetrafluoroborate.
Structurally, the compound consists of a central iodine atom bonded to two pyridine ligands, with the entire cation bearing a +1 charge. This cationic species is then balanced by the tetrafluoroborate anion (BF4-). The presence of the two pyridine ligands stabilizes the iodonium ion, making it a convenient and relatively mild reagent compared to other sources of electrophilic iodine.
Bis(pyridine)iodonium(I) tetrafluoroborate is generally used for the introduction of iodine atoms into organic molecules, often aromatic rings or alkenes. The reaction proceeds via electrophilic attack of the iodonium ion on the substrate, leading to iodination. The pyridine ligands are released in the process.
The reagent is typically handled under anhydrous conditions to prevent decomposition, as it is susceptible to hydrolysis. It offers advantages over other iodinating agents in terms of reactivity and selectivity in certain applications.