Unprecedented rhodium-mediated catalytic transfer hydrogenation of a phosphonate functionalized olefin in ecofriendly media

Abstract

RhCl 3 · xH 2O catalyst-mediated hydrogenation reactions of vinyl phosphonic diethyl ester H 2CCH–P(O)(OEt) 2 ( 1) have been investigated. Results demonstrate that the hydrogenation of H 2CCH–P(O)(OEt) 2 ( 1) to CH 3CH 2–P(O)(OEt)(OH) ( 2) proceeds in the presence of RhCl 3 · xH 2O catalyst, without any external hydrogen source and ancillary ligands, to near qualitative yields in ethanol and water media. 31P, 13C and 1H NMR and deuterium-labeling experiments provide evidence for the non-concerted mechanistic pathway associated with the hydrogenation of 1 to 2.