Phosphinoborinium cation: a synthon for cationic B-P bond systems.

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 B 2 P 2 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.