Process for preparing acylphosphanes and derivatives thereof

1. A process for the preparation of acylphosphanes or bisacylphosphanes of formula I

wherein

n and m are each independently of the other 1 or 2;

R 1 if n=1, is unsubstituted linear or branched C 1 -C 18 alkyl or C 2 -C 18 alkenyl; or

linear or branched C 1 -C 18 alkyl or C 2 -C 18 alkenyl substituted once or more than once by groups selected from:

halogen or CN, or

 —OR 10 , —SR 10 , —OCO—R 10 , —COO—R 10 , —CH═CH—CO—OR 10 or —C(C 1 -C 4 alkyl)=C(C 1 -C 4 alkyl)-CO—OR 10 ; wherein

R 10 is hydrogen, C 1 -C 18 alkyl, or C 2 -C 18 alkyl which is interrupted by one or several non-successive —O-atoms, a di,-tri,-tetra-or polyethylene glycol residue, C 3 -C 12 -cycloalkyl, tetrahydropyran -2-yl, phenyl-C 1 -C 4 -alkylene, phenyl-C 1 -C 4 -alkenylene, C 1 -C 6 alkyl substituted by halogen or substituted by cyclohexyl or cyclopentyl, or substituted by tetrahydrofuranyl, furanyl, isopropyl-4-methyl -coclohexyl, C 2 -C 18 -alkenyl, unsubstituted phenyl, naphthyl or biphenyl being unsubstituted or phenyl, naphthyl or biphenyl substituted by one to five C 1 -C 8 -alkyl, C 1 -C 8 -alkoxy, C 1 -C 8 -alkylthio and/or halogen; or

R 1 is linear or branched C 1 -C 18 alkyl or C 2 -C 18 alkenyl substituted by —CO—R 11 ; wherein

R 11 is C 1 -C 18 alkyl, or C 2 -C 18 alkyl which is interrupted by one or several non-successive —O-atoms, C 3 -C 12 -cycloalkyl, phenyl-C 1 -C 4 -alkylene, unsubstituted phenyl, naphthyl or biphenyl being unsubstituted or phenyl, naphthyl or biphenyl substituted by one to five C 1 -C 8 -alkyl, C 1 -C 8 -alkoxy, C 1 -C 8 -alkylthio and/or halogen or

R 1 is linear or branched C 1 -C 18 alkyl or C 2 -C 18 alkenyl substituted by —CO—(CH) 2 —CO—C 1 -C 6 alkyl, CO—(CH) 2 —CO-phenyl, or by CO—(CH) 2 —COO—C 1 -C 18 alkyl; or

R 1 is linear or branched C 1 -C 18 alkyl or C 2 -C 18 alkenyl substituted by —NR 12 R 13 , —N(R 12 )—CO—R 10 , —N(R 12 )—CO—OR 10 , —N(R 12 )—CO—NR 12 R 13 , —N(R 12 )—CO-Hal, —CO—NR 12 R 13 , wherein R 10 is as defined above and

R 12 and R 13 independently of one another are hydrogen, C 1 -C 18 alkyl, C 2 -C 18 alkyl which is interrupted by one or several non-successive O atoms, C 3 -C 12 -cycloalkyl, C 2 -C 18 -alkenyl, phenyl-C 1 -C 4 -alkyl, phenyl, naphthyl, pyridyl, the radicals phenyl, naphthyl or pyridyl being unsubstituted or substituted by one to five C 1 -C 8 -alkyl, C 1 -C 8 -alkoxy, C 1 -C 8 -alkylthio and/or halogen; or R 12 and R 13 forms a 5- or 6-membered O-, S- or N-containing heterocyclic ring; that may be further annelated by an aliphatic or aromatic ring; or

—SO 2 —R 10 , —SO 2 —OR 10 , —SO 2 —NR 12 R 13 , wherein R 10 ,R 12 and R 13 are as defined above; or

—PO(OC 1 -C 8 alkyl) 2 , or

—SiR 14 R 15 R 16 , wherein R 14 , R 15 and R 16 independently of one another are H, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, phenyl, C 7 -C 9 phenylalkyl, —OC 1 -C 8 alkyl, —O—SiR 17 R 18 R 19 , wherein R 17 , R 18 and R 19 are independently of each other H, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, phenyl, C 7 -C 9 phenylalkyl, —OC 1 -C 8 alkyl; or —CH═CH-phenyl or —C(C 1 -C 4 alkyl)=C(C 1 -C 4 alkyl)-phenyl, phenyl-C 1 -C 4 alkyl, phenyl, naphthyl, biphenyl, C 5 -C 12 cycloalkyl or a 5- or 6-membered O-, S- or N-containing heterocyclic, ring;

benzophenonyl, thioxanthonyl;

or

R 1 is C 2 -C 18 alkyl or C 2 -C 18 alkenyl which is interrupted by one or several non-successive —O—, —NH—, —NR 12 - or —S—atoms, and may additionally be substituted once or more than once by groups selected from:

halogen or CN, or —OR 10 , —SR 10 , —OCO—R 10 , —COO—R 10 , wherein R 10 is as defined above; or

—NR 12 R 13 , —N(R 12 )—CO—R 10 , —N(R 12 )—CO—OR 10 , —N(R 12 )—CO—NR 12 R 13 , —N(R 12 )—CO-Hal, —CO—NR 12 R 13 , wherein R 10 and R 12 and R 13 are as defined above; or

—SO 2 —R 10 , —SO 2 —OR 10 , —SO 2 —NR 12 R 13 , wherein R 10 , R 12 and R 13 are as defined above; or —PO(OC 1 -C 8 alkyl) 2 , or —SiR 14 R 15 R 16 , wherein R 14 , R 15 and R 16 are as defined above; or

phenyl-C 1 -C 4 alkyl, phenyl or C 5 -C 12 cycloalkyl;

or

R 1 is C 2 -C 18 alkyl or C 2 -C 18 alkenyl which is interrupted by —CO—, —COO—, —OCO—, —OCOO—, —CO—N(R 12 )—, —N(R 12 )—CO—, —N(R 12 )—CO—N(R 12 )—, —N(R 12 )—COO—, —COO—C 1 -C 18 alkylene, —COS—C 1 -C 18 alkylene, —SO 2 —, —SO 2 —O—, —SO 2 —N(R 12 )—, —(CH 3 ) 2 Si—[OSi(CH 3 ) 2 ] m - with m′=1-6, phenyl-C 1 -C 4 alkylene, phenylene, naphthylene, biphenylene, C 5 -C 12 cycloalkylene or a 5- or 6-membered O- , S- or N-containing heterocyclic ring; wherein R 12 is as defined above;

or

R 1 is trimethylsilyl or Hal-(CH 3 ) 2 Si—[OSi(CH 3 ) 2 ] m - or (CH 3 ) 3 Si—[OSi(CH 3 ) 2 ] m - with m′=1-6; or

R 1 is —COOH, —COO—R 10 , —CO—NR 12 R 13 , —CO-vinyl, —CO-phenyl which is unsubstituted or substituted by one or more —CH 3 , —OCH 3 , —Cl; wherein R 10 , R 12 and R 13 are as defined above; or

R 1 is phenyl-C 1 -C 4 alkyl, phenyl, naphthyl, biphenyl, C 5 -C 12 cycloalkyl or a 5- or 6-membered O-, S- or N-containing heterocyclic ring; all of the radicals phenyl, naphthyl, biphenyl, C 5 -C 12 cycloalkyl or the 5- or 6-membered —O- , S- or N-containing heterocyclic ring being unsubstituted or substituted by one to five halogen, C 1 -C 8 alkyl, C 1 -C 8 alkylthio, C 1 -C 8 alkoxy and/or —NR 12 R 13 ; wherein R 12 and R 13 are as defined above;

R 1 if n=2, is a divalent radical of the monovalent radical defined above or is

—CH 2 —COO-Z-OCO—CH 2 — wherein

Q is a single bond, —CH 2 —, —CR 6 R 7 —, —O—or —S—; R 4 and R 5 are each independently of the other hydrogen, C 1 -C 4 alkyl or C 1 -C 4 alkoxy; R 6 and R 7 are each independently of the other C 1 -C 4 alkyl;

Z is C 1 -C 18 alkylene or a bridge derived from a di,-tri,-tetra-or polyethylene glycol;

R 2 is C 1 -C 18 alkyl or C 2 -C 18 alkenyl ; C 1 -C 18 alkyl or C 2 -C 18 alkenyl substituted once or more than once by halogen; or

—OR 10 , —OCO—R 10 , —OCO-Hal, —COO—R 10 , —CH═CH—CO—OR 10 —N(R 12 )—CO—R 10 , —N(R 12 )—CO-Hal,; —C(C 1 -C 4 alkyl)=C(C 1 -C 4 alkyl)-CO—OR 10 , —CO—NR 12 R 13 , wherein R 10 , R 12 and R 13 are as defined above;

or —CH═CH-phenyl or —C(C 1 -C 4 alkyl)=C(C 1 -C 4 alkyl)-phenyl; C 3 -C 12 cycloalkyl, C 2 -C 18 alkenyl, phenyl-C 1 -C 4 alkyl, phenyl, naphthyl, anthryl, biphenyl or a 5- or 6-membered —O-, S- or N-containing heterocyclic ring, the radicals phenyl, naphthyl, biphenyl or the 5- or 6-membered —O-, S- or N-containing heterocyclic ring being unsubstituted or substituted by one to five halogen, C 1 -C 8 alkyl, C 1 -C 8 alkoxy and/or C 1 -C 8 alkylthio;

R 3 is one of the radicals defined under R 1 ;

the process comprises the steps

a) contacting elemental phosphorous or P(Hal) 3

with an alkali metal or an alkali earth metal optionally in the presence of a catalyst or an activator in a solvent to obtain metal phosphides Me 3 P or Me′ 3 P 2 , wherein Me is an alkali metal and Me′ is an alkali earth metal to obtain metal polyphosphides

b) optionally adding an alcohol, optionally in the presence of a catalyst or an activator to obtain metal dihydrogen phosphides MePH 2 ;

c) subsequent acylation reaction with m acid halides of formula III or m carboxylic acid esters of

formula IV

or, in case that in formula I m=1, with one carboxylic ester of formula IV followed by one acid halide of formula III or vice versa, wherein R is the residue of an alcohol and R 2 is as defined above;

d) alkylation reaction in case of m=2, subsequent reaction with an electrophilic agent R 1 Hal, R 1 —OSO 2 —O—R 1 , R 1 —OSO 2 —R 20 ,

(R 1 —O) 3 PO, H 2 C═CR 23 COOR 10 ,

wherein R 1 and R 10 are as defined above, R 20 is C 1 -C 8 alkyl,, C 1 -C 8 perfluoroalkyl, aryl or C 1 -C 4 -alkylaryl, R 21 is H or C 1 -C 8 alkyl; R 22 is C 1 -C 16 alkyl or C 2 -C 16 alkenyl substituted once or more than once by halogen —OR 10 , —NR 12 R 13 , —SR 10 , —OCO—R 10 , —OCO-Hal, —COO—R 10 , —N(R 12 )—CO—R 10 , —N(R 12 )—CO—OR 10 , —N(R 12 )—CO—NR 12 R 13 , —N(R 12 )—CO-Hal, —CO—NR 12 R 13 , —SO 2 —R 10 , —SO 2 —OR 10 , —SO 2 —NR 12 R 13 , —CH═CH—CO—OR 10 , —CH═CH-phenyl, —C(C 1 -C 4 alkyl)=C(C 1 -C 4 alkyl)-CO—OR 10 or —C(C 1 -C 4 alkyl)=C(C 1 -C 4 alkyl)-phenyl, phenyl-C 1 -C 4 alkyl, phenyl, naphthyl, biphenyl, C 5 -C 12 cycloalkyl or a 5- or 6-membered O-, S- or N-containing heterocyclic ring;

R 23 is H or CH 3 , and n=1-5 and R 10 , R 12 and R 13 is as defined above and in the case of m=1 reaction with an electrophilic agent R 1 Hal, R 1 —OSO 2 —O—R 1 , R 1 —OSO 2 —R 20 ,

 (R 1 —O) 3 PO, H 2 C═CR 23 COOR 10 ,

 wherein R 1 and R 10 ; R 20 , R 21 , R 22 and R 23 are as defined above or other electrophilic agents followed by the reaction with an electrophilic agent R 3 Hal R 3 —OSO 2 —O—R 3 , R 3 —OSO 2 —R 20 ,

 (R 3 —O) 3 PO, H 2 C═CR 23 COOR 10 ,

 wherein R 3 and R 10 , R 20 , R 21 , R 22 and R 23 are as defined above, to obtain the compounds of formula I.

2. A process according to claim 1 for the preparation of monoacyl -phosphanes of the formula I′ (compounds of the formula I with n=1 and m=1)

which process comprises the steps a), b) and c); and

d) reaction with an electrophilic agent R 1 Hal or other electrophilic agents containing the residue R 1 as defined for m=1 followed by the reaction with an electrophilic agent R 3 Hal or other electrophilic agents containing the residue R 3 as defined for m=1 to obtain the compounds of formula I′.

3. A process according to claim 1 for the preparation of symmetric bisacylphosphanes of the formula I″ (compounds of the formula I with n=1 and m=2)

which process comprises the steps a), b) and c) as defined for m=2; and

d) reaction with an electrophilic agent R 1 Hal or other electrophilic agents containing the residue R 1 as defined for m=2 to obtain the compounds of formula I″.

4. A process according to claim 1 for the preparation of unsymmetric bisacylphosphanes of the formula I′″(compounds of the formula I with n=1 and m=2)

wherein R 2 and R 2 ′ independently of one another are as defined for R 2 with the proviso that R 2 is not equal R 2 ′, which process comprises the steps a) and b); and

c) subsequent reaction with an acid halide of formula III or a carboxylic acid ester of formula IV

wherein R is the residue of an alcohol; then subsequent reaction with a second acid halide III′ or a second carboxylic acid ester of the formula IV′,

and

d) reaction with an electrophilic agent R 1 Hal or other electrophilic agents containing the residue R 1 as defined for m=2

to obtain the compounds of formula I′″.

5. A process according to claim 1 , wherein n=1 and

R 1 is phenyl, linear or branched C 1 -C 8 alkyl or C 2 -C 18 alkenyl or is linear or branched C 1 -C 8 alkyl or C 2 -C 18 alkenyl substituted by CN, trifluormethyl, oxiranyl, isoindole-1,3-dione, —O—C 1 -C 18 alkyl, —O—benzyl, —CO-phenyl , —CO—C 1 -C 18 alkyl, —OCO—C 1 -C 18 alkyl; —OCO—C 1 -C 18 alkenyl; —COO—C 1 -C 18 alkyl;

—COO—C 1 -C 18 alkylene-phenyl, —COO—C 1 -C 18 alkylene-cycloalkyl, —COO—C 1 -C 18 alkylene-tetrahydrofuranyl, —COO—C 1 -C 18 alkylene-furanyl, —COO—cycloalkyl, —COO—C 1 -C 18 alkenyl; —COO—C 1 -C 18 alkenylene-phenyl; —COO—(CH 2 ) 2 - 3 —Cl, —COO—[(CH 2 ) 2 - 3 —O] 1-10 —C 1 -C 6 alkyl; —COO—[(CH 2 ) 2 - 3 —O] 1-10 —C 1 -C 6 —OH, —CO—CH 2 —CO—C 1 -C 18 alkyl; —CO—CH 2 —COO—C 1 -C 18 alkyl, —O-tetrahydropyranyl, bicyclo[2.2.1]hept-2-en-5-yl)-methyl, PO(OC 1 -C 6 alkyl) 2 and

wherein R 2 is phenyl which is substituted in 2,6- or 2,4,6-position by C 1 -C 4 alkyl and/or C 1 -C 4 alkoxy, and/or chlorine; 2-ethoxy-naphth-1-yl, 2-methyl-naphth-1-yl or anthr-9-yl.

6. A process according to claim 1 which process comprises, as an additional step, oxidation or reaction with sulfur of the acylphosphane of formula I for the preparation of (bis)acylphosphane oxides and (bis)acylphosphane sulfides of formula IV

wherein

Z is O or S.

7. A process according to claim 1 for the preparation of (bis)acylphosphanes of formula I, the process comprising the steps of:

a) contacting red phosphorous or PCI 3 with an alkali metal in the presence of a solvent and optionally in the presence of polycyclic hydrocarbon catalyst,

b) adding a sterically hindered alcohol;

c) subsequent reaction with two equivalents of an acid halide Hal-CO—R 2 to obtain a metal bisacylphosphide [R 2 —CO—P═C(OMe)R 2 ], wherein Me is Na or Li; or with one equivalent of a caboxylic acid ester RO—CO—R 2 , followed by one equivalent of an acid halide Hal-CO—R 2 ′ to obtain a metal bisacylphosphide [R 2 —CO—P═C(OMe)R 2 ′], wherein Me is an alkali metal

d) subsequent reaction with an electrophilic agent R 1 Hal or R 1 OSO 2 OR 1 , to obtain the compounds of formula I.

8. A process according to claim 7 , wherein in step a) sodium in liquid ammonia is contacted with red phosphorus in tetrahydrofuran.