Innenrücktitelbild: Salt Metathesis: Tetrafluoroborate Anion Rapidly Fluoridates Organoboronic Acids to give Organotrifluoroborates (Angew. Chem. 16/2023)

Abstract

Salt metathesis and BFX (boron–fluoride exchange) of BF4− with boronic acids generates RBF3− derivatives, thus showing the solvolytic lability of BF4− that enables its use as a fluorinating agent, even though many highly reactive reagents employ BF4− as a non-reactive counteranion. In their Research Article (e202215371), David M. Perrin and co-workers report the synthesis of RBF3− derivatives via a salt metathesis reaction using a series of MBF4 salts in methanol. This work highlights the proclivity of BF4−, generally considered weakly coordinating and unreactive, to rapidly fluorinate boronic acids.