Introduction
<P>Organotrifluoroborate salts are a unique class of organoboron
compounds that have emerged as promising synthetic reagents. The
tetracoordinate nature of the boron in these complexes, enhanced
by strong boron-fluorine bonds, was anticipated to prevent undesired
typical reactions of trivalent organoborons. This, in turn, would
make the organotrifluoroborates essentially a protected boronic acid
or boronate ester reagents.
[
¹]
</P><P>The most convenient method for the preparation of these compounds
from boronic acids and derivatives utilizing the readily available
and inexpensive KHF
2 was described by Vedejs and co-workers.
[
²]
In combination with this
process, potassium organotrifluoroborates can be readily prepared
by the transmetalation of organolithium or organomagnesium reagents
with trialkylborates.
[
³]
Alternatively,
they can be synthesized by various catalyzed or uncatalyzed hydroborations
of alkynes or alkenes.
[
4]
</P><P>The utilization of organotrifluoroborates in organic synthesis
led to the preparation of more functionalized compounds. In this
way, several functional group inter-conversion reactions have been
performed,
[
5]
which expands the range
of retrosynthetic pathways using organotrifluoroborates
as key intermediates in complex molecule synthesis.</P>
