Introduction <P>Ionic liquids
[
1 ]
as green high tech reaction media of the future are considered as environmentally
friendly substitutes for volatile organic solvents, because of their low vapor pressures
and their ability to act as catalysts. They also possess several other attractive
properties,
[
2-4 ]
including chemical and thermal stability, non-flammability, high ionic conductivity,
a wide electrochemical potential window, and are 100% recyclable solvent media for
synthesis and catalytic processes.</P><P>Ionic liquids first described in 1914,
[
5 ]
consist of inorganic anions and nitrogen containing organic cations whose chemical
and physical properties can be finely tuned for a range of applications by varying
the cations or anions.
4
</P><P>Ionic liquid, [bmim][BF
4 ], can be easily prepared
[
6 ]
from
N -methylimidazole. The crude
1 obtained was purified by filtering through silica gel followed by washing with saturated
Na
2 CO
3 to give pure
1 (Scheme 1), which is now commercially
[
7 ]
available. It showed enhanced reactivity and selectivity in reactions like hydrogenation,
[
8 ]
coupling,
[
9 ]
carbonylation,
[
10 ]
and cycloaddition
[
11 ]
in comparision with several other ionic liquids. </P>
<P>The toxicological and/or eco-toxicological effects
[
12 ]
of
1 in comparision with volatile organic solvents is uncertain.</P>
