Method for producing mono-hydroxy-functionalized dialkylphosphinic acids, esters and salts using a vinyl ester of a carobxylic acid and the use thereof

A method for producing monohydroxy-functionalized diaikylphosphinic acids, esters or salts comprising the steps of

• a) reacting a phosphinic acid source (I)
• with olefins (IV)
• wherein the reaction is carried out
• in the presence of a catalyst A to form an alkyiphosphonous acid, salt or ester (II)
• b) reacting the alkyllphosphonous acid, salt or ester (II) with at least one vinyl ester of a carboxylic acid (V)
• in the presence of at least one catalyst B to form the monofunctionalized dialkylphosphinic acid derivative (VI)
• and
• c) reacting the monofunctionalized dialkylphosphinic acid derivative (VI) in the presence of at least one catalyst C to form the monofunctionalizect dialkylphosphinic acid derivative (III)
• where R1, R2, R3, R4, R5, R6, R7, R8 are identical or different and are H, methyl or ethyl, and X is H, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, ethylene glycol, propyl glycol, Mg, Al, Ti, Fe, Zn, Ce or a combination thereof and the catalyst A is selected from the group consisting of transition metals, transition metal compounds, a transition metal and at least one ligand, a transition metal compound and at least one ligand and a combination thereof, and the catalyst B is selected from the group consisting of hydrogen peroxide, sodium peroxide, lithium peroxide, potassium persulfate, sodium persulfate, ammonium persulfate, sodium peroxodisulfate, potassium peroxoborate, peracetic acid, benzoyl peroxide, di-t-butyl peroxide and/or peroxodisulfuric, acid and/or comprises azodiisobutyronitrile, 2,2′-azobis(2-amidinopropane) dihydrochloride, 2,2′-azobis(N,N-dimethyleneisobutyramidine) dihydrochloride and mixtures thereof and the catalyst C is selected from the group consisting of bases which are lithium, lithium hydride, lithium aluminohydride, methyllithium, butyllithium, t-butyllithium, lithium diisopropylamide, sodium, sodium hydride, sodium borohydride, sodium methoxide, sodium ethoxide, sodium butoxide, potassium methoxide, potassium ethoxide or potassium butoxide sodium hydroxide, potassium hydroxide, lithium hydroxide, barium hydroxide and ammonium hydroxide or catalyst C comprises a mineral acid or mixtures thereof.