Process for preparing mono-carboxy-functionalized dialkylphosphinic acids, esters and salts by means of alkylene oxides and use thereof

1. A process for preparing monocarboxy-functionalized dialkylphosphinic acids, esters or salts thereof comprising the steps of:

a) reacting a phosphinic acid source (I)

with olefins (IV)

in the presence of a catalyst A to form an alkylphosphonous acid, salt or ester (II)

b) reacting the alkylphosphonous acid, salt or ester (II) with at least one alkylene oxide (V)

in the presence of a catalyst B and a base to form a monofunctionalized dialkylphosphinic acid derivative (VI)

and

c) reacting the monofunctionalized dialkylphosphinic acid derivative (VI) with an oxidizing agent, with an oxidizing agent and water or in the presence of a catalyst C with oxygen and water to form a monocarboxy-functionalized dialkylphosphinic acid derivative (III)

wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 are identical or different and are H, C 1 -C 18 -alkyl, C 6 -C 18 -aryl, C 6 -C 18 -aralkyl, C 3 -C 18 -alkylaryl, CN, CHO, OC(O)CH 2 CN, CH(OH)C 2 H 5 , CH 2 CH(OH)CH 3 , 9-anthracene, 2-pyrrolidone, (CH 2 ) m OH, (CH 2 ) m NH 2 , (CH 2 ) m NCS, (CH 2 ) m NC(S)NH 2 , (CH 2 ) m SH, (CH 2 ) m S-2-thiazoline, (CH 2 ) m SiMe 3 , C(O)R 7 , (CH 2 ) m C(O)R 7 , CH═CHR 7 or CH═CH—C(O)R 7 and where R 7 is C 1 -C 8 -alkyl or C 6 -C 18 -aryl and m is an integer from 0 to 10 and X and Y are identical or different and are H, C 1 -C 18 -alkyl, C 6 -C 18 -aryl, C 6 -C 18 -aralkyl, C 6 -C 18 -alkylaryl, (CH 2 ) k OH, CH 2 —CHOH—CH 2 OH, (CH 2 ) k O(CH 2 ) k H, (CH 2 ) k —CH(OH)—(CH 2 ) k H, (CH 2 —CH 2 O) k H, (CH 2 —C[CH 3 ]HO) k H, (CH 2 —C[CH 3 ]HO) k (CH 2 —CH 2 O) k H, (CH 2 —CH 2 O) k (CH 2 —C[CH 3 ]HO)H, (CH 2 —CH 2 O) k -alkyl, (CH 2 —C[CH 3 ]HO) k -alkyl, (CH 2 —C[CH 3 ]HO) k (CH 2 —CH 2 O) k -alkyl, (CH 2 —CH 2 O) k (CH 2 —C[CH 3 ]HO)O-alkyl, (CH 2 ) k —CH═CH(CH 2 ) k H, (CH 2 ) k NH 2 or (CH 2 ) k N[(CH 2 ) k H] 2 , where k is an integer from 0 to 10, or X is Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Cu, Ni, Li, Na, K, H or a protonated nitrogen base and the catalysts A and C comprising a transition or a transition metal compound or catalyst systems composed of a transition metal, transition metal compound and at least one ligand, and the catalyst B is consisting of Lewis acids.

2. The process according to claim 1 wherein the monocarboxy-functionalized dialkylphosphinic acid, its salt or ester (III) obtained after step c) is subsequently reacted in a step d) with a metal compound, a protonated nitrogen base or a combination thereof, wherein the metal compound is Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na or K to form the monocarboxy-functionalized dialkylphosphinic acid salts (III) of the metal compound, of the nitrogen base or a combination thereof.

3. The process according to claim 1 wherein the alkylphosphonous acid, salt or ester (II) obtained after step a), monofunctionalized dialkylphosphinic acid, salt or ester (VI) obtained after step b) or the monocarboxy-functionalized dialkylphosphinic acid, salt or ester (III) obtained after step c) is esterified with an alkylene oxide, a linear or branched, saturated or unsaturated, monohydric or polyhydric organic alcohol having a carbon chain length of C 1 -C 18 or a combination thereof, and the resulting alkylphosphonous ester (II) or monofunctionalized dialkylphosphinic ester (VI) or the monocarboxy-functionalized dialkylphosphinic ester (III) are subjected to the further reaction steps b or c).

4. The process according to claim 1 , wherein C 6 -C 18 -aryl, C 6 -C 18 -aralkyl or C 6 -C 18 -alkylaryl are substituted with SO 3 X 2 , C(O)CH 3 , OH, CH 2 OH, CH 3 SO 3 X 2 , PO 3 X 2 , NH 2 , NO 2 , OCH 3 , SH OC(O)CH 3 or a combination thereof.

5. The process according to claim 1 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 8 are identical or different and are H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl or phenyl.

6. The process according to claim 1 , wherein X and Y are identical or different and are H, Ca, Mg, Al, Zn, Ti, Fe, Ce, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl, ethylene glycol, propyl glycol, butyl glycol, pentyl glycol, hexyl glycol, allyl or glycerol.

7. The process according to claim 1 , wherein the transition metal or the metal in the transition metal compounds is selected from the first, seventh or eighth transition groups.

8. The process according to claim 1 , wherein the transition metal or the transition metal of the transition metal compounds is rhodium, nickel, palladium, platinum, ruthenium or gold.

9. The process according to claim 1 , wherein the base in step b) is selected from the group consisting of metals, metal hydrides, organometal compounds and metal alkoxides, wherein the organometal compounds are selected from the group consisting of (C 6 H 5 ) 3 SnR 2 , CuR 2 , RAlCl 2 , R 2 AlCl, R 3 Al, (RO) 3 Al, R 3 TiCl, (RO) 4 Ti, RSnO 3 SCF 3 , R 3 B and B(OR) 3 where R is independently H, C 1 -C 12 -alkyl, C 6 -C 18 -aryl, C 6 -C 18 -alkylaryl, C 6 -C 8 -arylalkyl, CF 3 SO 3 or CH 3 C 5 H 4 SO 3 .

10. The process according to claim 1 , wherein the oxidizing agent is potassium permanganate, manganese dioxide, chromium trioxide, potassium dichromate, pyridine dichromate, pyridine chlorochromate, Collins reagent, Jones reagent, Corey-Gilman-Ganem reagent, Dess-Martin periodinane, o-iodoxybenzoic acid, ruthenium tetroxide, ruthenium dioxide, tetra-n-propyl perruthenate, ruthenium trichloride/sodium periodate, ruthenium dioxide/sodium periodate, chlorine, hypochlorite or peroxo compounds, wherein the peroxo compounds are selected from the group consisting of peroxomonosulfuric acid, potassium monopersulfate (potassium peroxomonosulfate), peroxodisulfuric acid, potassium persulfate (potassium peroxodisulfate), sodium persulfate (sodium peroxodisulfate) and ammonium persulfate (ammonium peroxodisulfate).

11. The process according to claim 1 , wherein the at least one alkylene oxide (V) is ethylene oxide, 1,2-propylene oxide, 1,2-epoxy-butane, 1,2-epoxyethylbenzene, (2,3-epoxypropyl)benzene, 2,3-epoxy-1-propanol, or a combination thereof.