Organotrifluoroborate Salts

Introduction

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]

The most convenient method for the preparation of these compounds from boronic acids and derivatives utilizing the readily available and inexpensive KHF₂ 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]

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.

References

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