Phosphinoborinium cation: a synthon for cationic B–P bond systems

Abstract

Herein, we report access to phosphinoborinium cations via heterolytic cleavage of the boron–bromide bond in bromophosphinoborane. The product of the reaction was isolated as a dimeric dication possessing a planar B₂P₂ core. Activation of the C–H and C–P bonds in the dication led to the formation of the borinium–phosphaborene adduct. Reactivity studies revealed that the title cation exhibits ambiphilic properties and intramolecular frustrated Lewis pair features.