| abstract |
The present invention relates to processes for the preparation of ethylenically dialkylphosphinic acids, esters and salts and their use as flame retardants. The claimed method comprises: comprising the steps of: a) reacting a phosphonic acid source (I) with an olefin (IV) in the presence of catalyst A to obtain an alkylphosphonous acid (II), or a salt or ester thereof, b) reacting the alkylphosphonous acid (II) obtained in this way, or a salt or ester thereof, and an acetylene compound (V) in the presence of catalyst B to give an ethylenically dialkylphosphinic acid derivative (III) Lt; / RTI & The catalyst A is a catalyst system composed of a transition metal and / or a transition metal compound and a transition metal and / or a transition metal compound and / or at least one ligand, and the catalyst B is electromagnetic radiation. (III) |