Palladium Catalyzed Preparation of Monoaryl and Diarylphosphinates from Methyl Phosphinate

All articles of this category A simple and effective preparation of methyl esters of monoarylphosphinic acids has been developed, which involves palladium catalyzed coupling of aryl iodides with methyl phosphinate in the presence of tertiary amines or propylene oxide (1,2-epoxypropane). This procedure is compatible with various functional groups, and proceeds in reasonable yield despite the thermal and hydrolytic sensitivity of methyl phosphinate. Symmetrically substituted diarylphosphinates may also be prepared using two equivalents of the aryl iodide. Unsymmetrically substituted diarylphosphinates are readily obtained from the monoarylphosphinates by known methods, or by palladium catalyzed reaction of a second aryl iodide without isolation of the intermediate monoarylphosphinate derived from methyl phosphinate.