Introduction <P>There is a great interest of organic chemists in hypervalent iodine reagents because
a wide range of reactions can be performed selectively under mild conditions and,
in some cases, catalytically.
[
1 ]
Fluorinated molecules are highly valuable due to the unique characteristics displayed
by the fluorine atom.
[
2 ]
</P><P>4-Iodotoluene difluoride (
p -TolIF
2 ,
1 ) is a hypervalent iodine reagent that promotes chemoselective fluorinations avoiding
the use of fluorine gas, as well as the expensive xenon difluoride. Several N-fluoro
compounds have been developed as stable and effective fluorinating reagents; their
preparation, however, generally demands the use of fluorine gas. Compound
1 is usually preferred over its iodobenzene difluoride analogue because of easier
preparation, purification, and handling.</P>
Preparation <P>Compound
1 is commercially available. However, it can be prepared in different ways from 4-iodotoluene.
[
3 ]
In one of them, the use of harmful gases or mercury salts is avoided (Scheme 1).
[
4 ]
</P>
Scheme 1
