Benzyl potassium


Benzyl potassium is an organopotassium compound with the formula C6H5CH2K that takes the form of an air sensitive orange powder. Like organo-alkali metal reagents in general, benzyl potassium is highly reactive, so much so that its use in coordinating solvents such as ethers and amines is less common than in hydrocarbons, as gradual decomposition occurs.

Synthesis

One early synthesis proceeds by two-step transmetallation reaction via p-tolylpotassium:
A modern synthesis involves the reaction of butyllithium, potassium tert-butoxide, and toluene. Although potassium hydride can also be used as a strong base for preparing potassium salts, benzyl potassium has the advantage of being molecular and hence more fast-acting.