Diphenylphosphine oxide


Diphenylphosphine oxide is an organophosphorus compound with the formula 2PH. It is a white solid that soluble in polar organic solvents. The compound is used in Buchwald-Hartwig coupling reactions to introduce a diphenylphosphino substituent. Analogous to the behavior of phosphorous acid, diphenylphosphine oxide exists in equilibrium with a minor tautomer hydroxydiphenylphosphine 2POH.

Synthesis

Diphenylphosphine oxide can be prepared by the reaction of phosphonic esters, such as diethylphosphite, with Grignard reagents. Alternatively, it may be prepared by the partial hydrolysis of chlorodiphenylphosphine or diphenylphosphine.

Reactions

Organophosphinous acids are deoxygenated with DIBAH. The resulting secondary phosphines are precursors to phosphine ligands.