REACTIONS OF TETRAPHENYLDIPHOSPHINE WITH ALIPHATIC CARBOXYLIC ACIDS AND WITH ALDEHYDES

Tetraphenyldiphosphine and aliphatic carboxylic acids at 180° give 1-hydroxy-1,1-bisdiphenylphosphinylalkanes which slowly rearrange to 1-diphenylphosphinyloxyalkyldiphenylphosphine oxides. The acids Ph·X·CH2·CO2H (X = O or S) also give the esters Ph2P(:O)XPh. Di- and tri-phenylacetic acids give only di- and tri-phenylmethanes with the formation of carbon monoxide. Tetraphenyldiphosphine and aldehydes at 180° give 1- hydroxyalkyldiphenylphosphines and 1-acyloxyalkyl-diphenylphosphines isolated as their oxides. With aromatic aldehydes having a para-substitutent capable of electron supply, these are further reduced to benzyldiphenylphosphine oxides.