BRØNSTED-ACIDIC FLUOROALKYL PHOSPHONATES

Abstract

The invention relates to Brnsted-acidic fluoroalkyl phosphonates as bifunctional catalysts and to processes for the preparation thereof.

Claims

1. Compounds of the formula I
[Kt].sup.z+z[R.sub.fP(O)(OH)O].sup.I, where R.sub.f corresponds to the formula C.sub.nF.sub.(2n+1)(m+k)H.sub.mX.sub.k, X denotes Cl, Br or I, n denotes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, m denotes 0, 1, 2, 3 or 4, k denotes 0, 1 or 2, with the proviso that, if n denotes 1, m denotes 0, 1 or 2 and/or k denotes 0, 1 or 2 and [Kt].sup.z+ denotes a singly, doubly, triply or multiply positively charged metal atom.

2. Compounds according to claim 1, where R.sub.f denotes a linear or branched perfluoroalkyl group having 1 to 12 C atoms.

3. Compounds according to claim 1, where [Kt].sup.z+ is selected from cations of the metals Li, Na, Ca, Mg, Ag, Fe, Co, Ni, Cu, Au, Al, In, Sn, Zn, Bi, Rh, Ru, Ir, Pd, Pt, Os, Cr, Mo, W, V, Nb, Ta, Ti, Zr, Hf, Y, Yb, La, Sc, Lu, Ce, Nd, Tb, Er, Eu or Sm.

4. Process for the preparation of compounds of the formula I according to claim 1, characterised in that a compound of the formula II
R.sub.fP(O)(OH).sub.2II, where R.sub.f has a meaning indicated in claim 1, is reacted with a metal which forms the future metal cation [Kt].sup.z+, or a compound of the formula III
[Kt].sup.z+z/b[An].sup.bIII, where [Kt].sup.z+ has a meaning indicated in claim 1, and [An].sup.b denotes [Cl].sup., [OH].sup., [CO.sub.3].sup.2 or [O].sup.2, where equimolar amounts of compounds of the formula II and of the formula III or of the metal are employed, which is determined by the valence of the cation [Kt].sup.z+ in the compound of the formula I.

5. Process according to claim 4, characterised in that the reaction is carried out in the presence or without the presence of water or an organic solvent.

6. Process for the preparation of the compounds of the formula I according to claim 1, characterised in that a compound of the formula IV
[Kt].sup.z+z/2[R.sub.fP(O)O.sub.2].sup.2IV, is reacted in a disproportionation reaction with a compound of the formula II
R.sub.fP(O)(OH).sub.2II, where R.sub.f corresponds to the formula C.sub.nF.sub.(2n+1)(m+k)H.sub.mX.sub.k, X denotes Cl, Br or I, n denotes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, m denotes 0, 1, 2, 3 or 4, k denotes 0, 1 or 2, with the proviso that, if n denotes 1, m denotes 0, 1 or 2 and/or k denotes 0, 1 or 2 and [Kt].sup.z+ denotes a singly, doubly, triply or multiply positively charged metal atom.

7. A method for performing catalysis which comprises using compounds of the formula I according to claim 1 as bifunctional catalysts.

8. Bifunctional catalysts of the formula I according to claim 1 for use in organic synthesis.

9. Bifunctional catalysts of the formula I according to claim 8 for use in Lewis acid-catalysed and/or Brnsted acid-catalysed reactions or domino reactions selected from a condensation reaction, alcoholysis, aldol reaction, Mukaiyama aldol reaction, Gattermann-Koch reaction, Beckmann and Fries rearrangement, Friedel-Crafts acylation, Friedel-Crafts alkylation, Mannich reaction, Diels-Alder reaction, aza-Diels-Alder reaction, Baylis-Hillman reaction, Reformatsky reaction, Claisen rearrangement, Prins cyclisation reaction, allylation of carbonyl compounds, cyanation of aldehydes and ketones, cyanosilylation of aldehydes and ketones, 1,3-dipolar cycloaddition, hydration of alkenes, cyclisation reaction, polymerisation, Michael reaction, oxidation and reduction reactions.

Description

EXAMPLE 1

Preparation of iron(III) tris[hydrogen(pentafluoroethyl)-phosphonate]

[0082]
FeCl.sub.3+3C.sub.2F.sub.5P(O)(OH).sub.2.fwdarw.Fe[C.sub.2F.sub.5P(O).sub.2OH].sub.3+3HCl

[0083] Anhydrous iron(III) chloride, FeCl.sub.3 (1.49 g, 9.15 mmol), is mixed with pentafluoroethylphosphonic acid, C.sub.2F.sub.5P(O)(OH).sub.2 (5.49 g, 27.45 mmol), and ground intensively in an agate mortar under an argon atmosphere. The hydrogen chloride formed is removed by means of a gentle stream of argon. The resultant white solid is transferred into a round-bottomed flask and heated at 140 C. for 20 minutes with stirring. The solid is subsequently dried at 1 kPa and 50 C. for two hours. Iron(III) tris[hydrogen(pentafluoroethyl)phosphonate], Fe[C.sub.2F.sub.5P(O).sub.2OH].sub.3 (5.64 g, 8.644 mmol, 94% of the theoretical yield), is isolated as a white solid.

[0084] The isolated product is characterised by means of .sup.1H, .sup.19F and .sup.31P spectra, elemental analysis, vibration spectroscopy and ion chromatography.

[0085] NMR (solvent: CD.sub.3OD; in ppm),

[0086] .sup.19F-NMR: 83.0 s (3F), -128.3 d, .sup.2J.sub.F,P=76 Hz, (2F).

[0087] .sup.31P-NMR: 2.3 t, .sup.2J.sub.P,F=76 Hz.

[0088] NMR (solvent: dimethyl sulfoxide-d6, in ppm)

[0089] .sup.1H NMR: 7.27 (s, OH).

[0090] .sup.19F NMR: 80.6 (s, 3F), 126.0 (d, .sup.2J.sub.F,P=73 Hz, 2F).

[0091] .sup.31P NMR: 4.5 (t, .sup.2J.sub.P,F=73 Hz).

[0092] Elemental analysis:

[0093] Theoretical % fr C.sub.6H.sub.3F.sub.15FeO.sub.9P.sub.3: C, 11.04, H, 0.46.

[0094] Experimental %: C, 10.98, H, 0.46.

[0095] IR spectrum (cm.sup.1):

[0096] 3643 (20), 3573 (17), 2800 (9), 1772 (5), 1628 (5), 1326 (33), 1209 (99), 1184 (96), 1167 (98), 1107 (100), 1008 (37), 959 (37), 942 (36), 912 (43), 754 (20), 635 (20), 575 (50).

[0097] Raman spectrum (cm.sup.1)

[0098] 1328 (16), 1181 (83), 1129 (29), 1015 (16), 949 (8), 915 (14), 756 (100), 637 (22), 595 (22), 526 (11), 487 (9), 467 (11), 400 (13), 367 (32), 316 (18), 302 (19), 245 (20), 172 (18), 140 (20), 123 (19), 95 (21).

[0099] Ion chromatography:

[0100] chloride ions <1 ppm, t (min): phosphonate: 12.25.

[0101] Fe(II) detection negative:

[0102] Fe[C.sub.2F.sub.5P(O).sub.2OH].sub.3 (0.0059 g, 0.009 mmol) is dissolved in H.sub.2O (bidist, 0.581 g), and two drops of a two percent alcoholic solution of 2,2-bipyridine are added. The solution becomes cloudy and changes colour to pale yellow. After addition of two drops (0.074 mg) of an iron(II) sulfate solution (c=0.0008 mol.Math.l.sup.1) a clear red coloration occurs after 5 minutes.

EXAMPLE 2

Preparation of aluminium(III) tris[hydrogen(pentafluoroethyl)phosphonate]

[0103] ##STR00002##

[0104] Pentafluoroethylphosphonic acid, (C.sub.2F.sub.5P(O)(OH).sub.2 (19.25 g, 96.2 mmol), and aluminium trichloride, AlCl.sub.3 (4.27 g, 32.1 mmol), are initially introduced in a 100 ml round-bottomed flask. Diethyl ether (42.67 g, 575.7 mmol) is added to the mixture at 0 C. (ice bath), and the reaction mixture is evaporated to of the volume at a bath temperature of 55 C. 45 ml of diethyl ether are added at room temperature and distilled off at a bath temperature of 55 C. This operation is repeated (at least 5 times) until chloride ions are no longer detectable in the distillate (AgNO.sub.3 soln.). The white, viscous crude product is dried at 0.1 Pa, firstly at room temperature (36 h) and subsequently at 120 C. (5 h). Aluminium(III) tris(pentafluoroethylhydrogenphosphonate), Al[C.sub.2F.sub.5P(O).sub.2OH].sub.3 (19.39 g, 31.1 mmol, 97% of the theoretical yield), is isolated as a white solid yield.

[0105] The isolated product is characterised by means of .sup.1H, .sup.19F and .sup.31P NMR spectra, x-ray fluorescence analysis, elemental analysis and vibration spectroscopy.

[0106] NMR (solvent: 1-butyl-3-methylimidazolium trifluoromethanesulfonate;

[0107] CD.sub.3CN film, in ppm),

[0108] .sup.1H NMR: 10.40 (s, H).

[0109] .sup.19F NMR: 82.9 (s, 3F), 128.3 (d, .sup.2J.sub.F,P=85 Hz, 2F).

[0110] .sup.31P NMR: 3.8 (t, .sup.2J.sub.P,F=85 Hz).

[0111] X-ray fluorescence analysis:

[0112] Theoretical: Al:P:Cl=1:3:0.

[0113] Experimental: Al:P:Cl=1:2.99:0.

[0114] Elemental analysis:

[0115] Theoretical (%) fr AlC.sub.6F.sub.15H.sub.3O.sub.9P.sub.3: C, (11.55), H, (0.48).

[0116] Experimental (%): C, (11.49), H, (0.45).

[0117] IR spectrum (cm.sup.1):

[0118] 3666 (12), 1635 (17), 1530 (14), 1450 (13), 1392 (12), 1324 (38), 1213 (100), 1168 (76), 1121 (83), 991 (53), 953 (54), 828 (23), 777 (21), 754 (32), 635 (21), 577 (43).

[0119] Raman spectrum (cm.sup.1):

[0120] 1328 (10), 1239 (12), 1222 (10), 1204 (8), 1132 (4), 1117 (5), 1016 (6), 914 (10), 756 (100), 637 (15), 597 (13), 534 (6), 475 (4), 367 (10), 342 (3), 302 (5), 241 (6), 181 (3), 109 (1).

EXAMPLE 3

Preparation of copper (II) bis[hydrogen(pentafluoroethyl)-phosphonate]

[0121] ##STR00003##

[0122] Pentafluoroethylphosphonic acid, (C.sub.2F.sub.5P(O)(OH).sub.2 (3.75 g, 18.75 mmol), and copper(II) chloride, (1.26 g, 9.38 mmol), are initially introduced in a 100 ml round-bottomed flask. 100 ml of 1,4-dioxane are added at room temperature and distilled off at a bath temperature of 135 C. This operation is repeated (at least 20 times) until chloride ions are no longer detectable in the distillate (AgNO.sub.3 soln.). The grey crude product is dried at 0.1 Pa and 140 C. for 20 h, subsequently washed twice with 10 ml of dichloromethane and dried again at 0.1 Pa and 140 C. for 20 h. A chloride- and 1,4-dioxane-containing copper(II) bis(pentafluoroethylhydrogenphosphonate), Cu[C.sub.2F.sub.5P(O).sub.2OH].sub.2 (2.81 g, 6.09 mmol, 65% of the theoretical yield), are isolated as a grey solid.

[0123] The isolated product is characterised by means of .sup.1H, .sup.19F and .sup.31P NMR spectra, X-ray fluorescence analysis, elemental analysis and vibration spectroscopy.

[0124] NMR (solvent: 1-butyl-3-methylimidazolium trifluoromethanesulfonate;

[0125] CD.sub.3CN film, in ppm),

[0126] .sup.1H NMR: 12.13 (s, OH), 3.16 (s, CH.sub.2).

[0127] .sup.19F NMR: 82.9 (s, 3F), 128.3 (d, .sup.2J.sub.F,P=84 Hz, 2F).

[0128] .sup.31P NMR: 3.8 (t, .sup.2J.sub.P,F=84 Hz).

[0129] X-ray fluorescence analysis

[0130] Theoretical for Cu[C.sub.2F.sub.5P(O).sub.2OH].sub.1.58Cl.sub.0.42.2 C.sub.4H.sub.8O.sub.2

[0131] or Cu.sub.12C.sub.46H.sub.35F.sub.95O.sub.42P.sub.19C.sub.15: Cu:P:Cl=1:1.58:0.42.

[0132] Experimental: Cu:P:Cl=1:1.51:0.37.

[0133] Elemental analysis

[0134] Theoretical (%) for Cu[C.sub.2F.sub.5P(O).sub.2OH].sub.1.58Cl.sub.0.42.2 C.sub.4H.sub.8O.sub.2 or Cu.sub.12C.sub.46H.sub.35F.sub.95O.sub.42P.sub.19C.sub.15: C, (11.28), H, (0.72).

[0135] Experimental (%): C, (11.05), H, (0.82).

[0136] IR spectrum (cm.sup.1):

[0137] 3641 (37), 3402 (29), 1616 (26), 1323 (43), 1212 (100), 1158 (99), 1110 (83), 1005 (61), 957 (64), 928 (67), 873 (31), 752 (36), 633 (31), 588 (37), 576 (44).

EXAMPLE 4

Preparation of zinc(II) bis[hydrogen(pentafluoroethyl)-phosphonate]

[0138] ##STR00004##

[0139] Pentafluoroethylphosphonic acid, (C.sub.2F.sub.5P(O)(OH).sub.2 (3.70 g, 18.5 mmol), and zinc(II) chloride (1.26 g, 9.3 mmol), are initially introduced in a 100 ml round-bottomed flask. 100 ml of 1,4-dioxane are added at room temperature and distilled off a bath temperature of 135 C. This operation is repeated (at least 15 times) until chloride ions are no longer detectable in the distillate (AgNO.sub.3 soln.). The crude product changes colour to brown in the process. The brown, highly viscous mass dried at 0.1 Pa and 140 C. for 20 h, subsequently washed twice with 10 ml of dichloromethane and dried again in vacuo. A chloride- and 1,4-dioxane-containing zinc(II) bis(pentafluoroethylhydrogenphosphonate), Zn[C.sub.2F.sub.5P(O).sub.2OH].sub.2 (3.28 g, 6.75 mmol, 73% of the theoretical yield) are isolated as a grey solid.

[0140] The isolated product is characterised by means of .sup.1H, .sup.19F and .sup.31P NMR spectra, x-ray fluorescence analysis, elemental analysis and vibration spectroscopy.

[0141] NMR (solvent: CD.sub.3CN; in ppm),

[0142] .sup.1H NMR: 10.41 (s, OH), 3.64 (s, CH.sub.2).

[0143] .sup.19F NMR: 82.9 (s, 3F), 128.3 (d, .sup.2J.sub.F,P=85 Hz, 2F).

[0144] .sup.31P NMR: 3.5 (t, .sup.2J.sub.P,F=85 Hz).

[0145] X-ray fluorescence analysis:

[0146] Theoretical for Zn[C.sub.2F.sub.5P(O).sub.2OH].sub.2.0.25 C.sub.4H.sub.8O.sub.2 or Zn.sub.2C.sub.10H.sub.8F.sub.20O.sub.13P.sub.4: Zn:P:Cl=1:2:0.

[0147] Experimental: Zn: P:Cl=1:1.98:0.10.

[0148] Elemental analysis:

[0149] Theoretical (%) for Zn[C.sub.2F.sub.5P(O).sub.2OH].sub.2.0.25 C.sub.4H.sub.8O.sub.2 or Zn.sub.2C.sub.10H.sub.8F.sub.20O.sub.13P.sub.4: C, (12.37), H, (0.83).

[0150] Experimental (%): C, (12.50), H, (0.78).

[0151] IR spectrum (cm.sup.1):

[0152] 3619 (10), 1622 (11), 1458 (7), 1382 (6), 1325 (38), 1211 (100), 1165 (80), 1115 (92), 1081 (68), 1007 (52), 981 (38), 945 (60), 851 (32), 754 (29), 634 (25), 575 (44).

EXAMPLE 5

Preparation of nickel(II) bis[hydrogen(pentafluoroethyl)-phosphonate]

[0153] ##STR00005##

[0154] Pentafluoroethylphosphonic acid, (C.sub.2F.sub.5P(O)(OH).sub.2 (4.04 g, 20.2 mmol), and nickel(II) chloride (1.34 g, 10.3 mmol), are initially introduced in a 100 ml round-bottomed flask. 100 ml of 1,4-dioxane are added at room temperature and distilled off at a bath temperature of 135 C. This operation is repeated (at least 15 times) until chloride ions are no longer detectable in the distillate (AgNO.sub.3 soln.). The crude product changes colour to orange in the process. The orange, highly viscous mass is dried at 0.1 Pa and 140 C. for 10 h, subsequently washed with twice 10 ml of dichloromethane and dried again in vacuo. A chloride- and 1,4-dioxane-containing nickel(II) bis(pentafluoroethylhydrogenphosphonate), Ni[C.sub.2F.sub.5P(O).sub.2OH].sub.2 (4.22 g, 9.24 mmol, 91% of the theoretical yield) is isolated as an orange solid. The isolated product is characterised by means of .sup.1H, .sup.19F and .sup.31P NMR spectra, x-ray fluorescence analysis, elemental analysis and vibration spectroscopy.

[0155] NMR (solvent: D.sub.2O; in ppm),

[0156] .sup.19F NMR: 81.1 (s, 3F), 126.0 (d, .sup.2J.sub.F,P=75 Hz, 2F).

[0157] .sup.31P NMR: 2.3 (s, .sup.2J.sub.P,F=160 Hz).

[0158] IR spectrum (cm.sup.1):

[0159] 3659 (11), 1623 (9), 1613 (9), 1540 (6), 1459 (7), 1324 (40), 1216 (100), 1166 (83), 1115 (73), 1075 (57), 1003 (53), 934 (49), 872 (35), 753 (28), 633 (27), 576 (50).

EXAMPLE 6

Preparation of yttrium(III) tris[hydrogen(pentafluoroethyl)-phosphonate]

[0160] ##STR00006##

[0161] Yttrium(III) chloride, YCl.sub.3 (0.827 g, 4.24 mmol), is dissolved in 35 ml of dry acetone in a 100 ml round-bottomed flask. A solution of pentafluoroethylphosphonic acid, (C.sub.2F.sub.5P(O)(OH).sub.2 (2.54 g, 12.72 mmol), in 5 ml of acetone is subsequently added. A clear reddish solution is obtained. After addition of a further 30 ml of dry acetone, the solution is stirred at room temperature for 4 hours. The crude product is filtered off as a white solid. The solid is washed with twice with 5 ml of acetone and subsequently dried at 0.1 Pa and 50 C. (6 h). An acetone-containing yttrium(III) tris[hydrogen(pentafluoroethyl)phosphonate], Y[C.sub.2F.sub.5P(O).sub.2OH].sub.3 (2.03 g, 2.96 mmol, 70% of the theoretical yield), is isolated as a white solid.

[0162] The isolated product is characterised by means of .sup.1H, .sup.19F and .sup.31P NMR spectra, elemental analysis, vibration spectroscopy and ion chromatography.

[0163] NMR (solvent: 1-butyl-3-methylimidazolium trifluoromethanesulfonate; CD.sub.3CN film, in ppm)

[0164] .sup.1H NMR: 11.08 (s, OH), 2.11 (s, (CH.sub.3).sub.2CO); intensity ratio 1:1.

[0165] .sup.19F NMR: 82.9 (s, 3F), 128.3 (d, .sup.2J.sub.F,P=85 Hz, 2F).

[0166] .sup.31P NMR: 3.9 (t, .sup.2J.sub.P,F=85 Hz).

[0167] Elemental analysis

[0168] Theoretical (%) for Y[C.sub.2F.sub.5P(O).sub.2OH].sub.3.0.5 (CH.sub.3).sub.2CO or Y.sub.2C.sub.15H.sub.12F.sub.30O.sub.19P.sub.6: C, (12.60), H, (0.85).

[0169] Experimental (%): C, (12.93), H, (1.06).

[0170] IR spectrum (cm.sup.1)

[0171] 3691 (3), 3676 (3), 3576 (4), 2930 (10), 2340 (4), 1669 (19), 1425 (3), 1375 (4), 1326 (26), 1215 (100), 1168 (49), 1109 (78), 1005 (20), 944 (32), 752 (10), 633 (13), 581 (38), 562 (10).

[0172] Raman spectrum (cm.sup.1)

[0173] 2936 (18), 1577 (18), 1428 (24), 1327 (37), 1221 (44), 1180 (54), 1113 (34), 1014 (23), 947 (31), 802 (10), 754 (100), 634 (30), 596 (31), 528 (25), 457 (14), 374 (35), 328 (35), 295 (37), 248 (17), 155 (20), 80 (32).

[0174] Ion chromatography

[0175] chloride ions <1 ppm, t (min): phosphonate: 12.25.

EXAMPLE 7

Preparation of bismuth(III) tris[hydrogen(pentafluoroethyl)-phosphonate]

[0176] ##STR00007##

[0177] Pentafluoroethylphosphonic acid, (C.sub.2F.sub.5P(O)(OH).sub.2 (1.51 g, 7.56 mmol), and bismuth(III) chloride, (0.796 g, 2.52 mmol), are initially introduced in a 100 ml round-bottomed flask. 100 ml of 1,4-dioxane are added at room temperature and distilled off at a bath temperature of 135 C. This operation is repeated (at least 20 times) until chloride ions are no longer detectable in the distillate (AgNO.sub.3 soln.). The grey product is dried at 0.1 Pa and 130 C. for 20 h. Bismuth(III) tris(pentafluoroethylhydrogenphosphonate), Bi[C.sub.2F.sub.5P(O).sub.2OH].sub.3 (1.73 g, 2.15 mmol, 85% of the theoretical yield), is isolated as a grey solid.

[0178] The isolated product is characterised by means of .sup.1H, .sup.19F and .sup.31P NMR spectra, X-ray fluorescence analysis, elemental analysis and vibration spectroscopy.

[0179] NMR (solvent: 1-butyl-3-methylimidazolium trifluoromethanesulfonate; CD.sub.3CN film, in ppm),

[0180] .sup.1H NMR: 10.73 (s, OH).

[0181] .sup.19F NMR: 82.9 (s, 3F), 128.3 (d, .sup.2J.sub.F,P=85 Hz, 2F).

[0182] .sup.31P NMR: 3.9 (t, .sup.2J.sub.P,F=85 Hz).

[0183] NMR (solvent: dimethyl sulfoxide-d6, in ppm),

[0184] .sup.1H NMR: 12.41 (s, OH).

[0185] .sup.19F NMR: 80.4 (s, 3F), 125.3 (d, .sup.2J.sub.F,P=85 Hz, 2F).

[0186] .sup.31P NMR: 6.4 (t, .sup.2J.sub.P,F=85 Hz).

[0187] X-ray fluorescence analysis:

[0188] Theoretical for Bi[C.sub.2F.sub.5P(O).sub.2OH].sub.3: Bi:P:Cl=1:3:0.

[0189] Experimental: Bi: P:Cl=1:1.81:0.00.

[0190] Elemental analysis:

[0191] Theoretical (%) for Bi[C.sub.2F.sub.5P(O).sub.2OH].sub.3: C, (8.94), H, (0.38).

[0192] Experimental (%): C, (9.16), H, (0.38).

[0193] IR spectrum (cm.sup.1):

[0194] 3613 (13), 3593 (13), 1608 (9), 1324 (41), 1213 (85), 1160 (96), 1127 (90), 1062 (100), 1009 (69), 957 (69), 929 (65), 913 (57), 754 (38), 634 (26), 573 (42).

COMPARATIVE EXAMPLE 8A

Uncatalysed Michael Reaction of methyl vinyl ketone and (1-methoxy-2-methylprop-1-enyloxy)trimethylsilane

[0195] ##STR00008##

[0196] Methyl vinyl ketone, (0.564 g, 8.047 mmol) and (1-methoxy-2-methylprop-1-enyloxy)trimethylsilane, (1.58 g, 9.047 mmol) are combined in a 50 ml two-necked flask, fitted with reflux condenser and drying tube, and dissolved in dichloromethane (13.36 g). The reaction solution is investigated by .sup.1H-NMR spectroscopy and then stirred at room temperature for 30 hours. The reaction solution is then investigated again by .sup.1H-NMR spectroscopy, with no change compared with the first measurement being evident. The compounds detected at the end point with reference to the .sup.1H-NMR spectrum are the unchanged starting materials (1-methoxy-2-methylprop-1-enyloxy)-trimethylsilane and methyl vinyl ketone having the following shift values:

[0197] (1-Methoxy-2-methylprop-1-enyloxy)trimethylsilane:

[0198] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 3.47 (s, 3H), 1.55 (s, 3H), 1.51 (s, 3H), 0.20 (s, 9H).

[0199] Methyl vinyl ketone:

[0200] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 6.28 (m, 2H), 5.94 (d, .sup.3J.sub.H,H=10.1 Hz, 1H), 2.26 (s, 3H).

EXAMPLE 8B

Michael Reaction of methyl vinyl ketone and (1-methoxy-2-methylprop-1-enyloxy)trimethylsilane Catalysed by iron(III) tris-[hydrogen(pentafluoroethyl)phosphonate] (10 mol %)

[0201] Iron(III) tris[hydrogen(pentafluoroethyl)phosphonate], Fe[(C.sub.2F.sub.5)P(O).sub.2OH].sub.3 (0.388 g, 0.594 mmol), is suspended in dichloromethane (13.49 g) in a 50 ml two-necked flask with reflux condenser and drying tube. Methyl vinyl ketone (0.432 g, 6.16 mmol) and (1-methoxy-2-methylprop-1-enyloxy)-trimethylsilane (1.58 g, 9.04 mmol) are added to this suspension. After a reaction time of 3 hours, the conversion to methyl 2,2-dimethyl-5-oxohexenoate, determined using .sup.1H-NMR spectroscopy, is 98 mol %. The solvent dichloromethane is removed at 0.1 Pa and room temperature. Water (20 ml) is added to the residue, and the resultant emulsion is extracted three times with 20 ml of n-hexane. The catalyst remains in the aqueous phase. After evaporation of the combined n-hexane solutions, methyl 2,2-dimethyl-5-oxohexenoate (0.88 g, 5.11 mmol, 83% of the theoretical yield) can be isolated as a colourless liquid.

[0202] Methyl 2, 2-dimethyl-5-oxohexenoate:

##STR00009##

[0203] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 3.63 (s, C.sup.4H, 3H), 2.41 (m, C.sup.2H, 2H), 2.09 (s, C.sup.1H, 3H), 1.74 (m, C.sup.3H, 2H), 1.16 (s, C.sup.5,6H, 6H).

EXAMPLE 8C

Reaction from Example 8b Catalysed by iron(II) tris-[hydrogen(pentafluoroethyl)phosphonate] (4.95 mol %)

[0204] Iron(III) tris[hydrogen(pentafluoroethyl)phosphonate], Fe[(C.sub.2F.sub.5)P(O).sub.2OH].sub.3 (0.379 g, 0.581 mmol), is suspended in methyl vinyl ketone (0.432 g, 6.16 mmol) in a 50 ml two-necked flask with reflux condenser and drying tube. (1-Methoxy-2-methylprop-1-enyloxy)trimethylsilane (3.09 g, 17.70 mmol) is added to this suspension. The suspension warms. After a reaction time of 1 hour, water (20 ml) is added to the solution, and the resultant emulsion is extracted three times with 20 ml of n-hexane. After evaporation of the hexane and the (1-methoxy-2-methylprop-1-enyloxy-trimethylsilane employed in excess, methyl 2,2-dimethyl-5-oxohexenoate (1.50 g, 8.69 mmol, 74% of the theoretical yield) can be isolated as a colourless liquid at 90 C. and 0.1 Pa.

[0205] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 3.62 (s, C.sup.4H, 3H), 2.40 (m, C.sup.2H, 2H), 2.08 (s, C.sup.1H, 3H), 1.74 (m, C.sup.3H, 2H), 1.15 (s, C.sup.5,6H, 6H).

EXAMPLE 8D

Solvent-Free Michael Reaction of methyl vinyl ketone and (1-methoxy-2-methylprop-1-enyloxy)trimethylsilane Catalysed by aluminium(III) tris[hydrogen(pentafluoroethyl)phosphonate](4.95 mol %)

[0206] Aluminium(III) tris[hydrogen(pentafluoroethyl)phosphonate], Al[(C.sub.2F.sub.5)P(O).sub.2OH].sub.3 (0.259 g, 0.415 mmol), is suspended in (1-methoxy-2-methylprop-1-enyloxy)trimethylsilane (1.48 g, 8.51 mmol) in a 50 ml two-necked flask with reflux condenser and drying tube. Methyl vinyl ketone (0.586 g, 8.36 mmol) is added to this suspension. The suspension warms. After a reaction time of 5 minutes, water (0.3 ml) is added to the suspension. The suspension is filtered, and the water is removed in vacuo at room temperature. Methyl 2,2-dimethyl-5-oxohexenoate (0.81 g, 4.73 mmol, 57% of the theoretical yield) can be isolated as a colourless liquid at 90 C. and 0.1 Pa.

[0207] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 3.62 (s, C.sup.4H, 3H), 2.41 (m, C.sup.2H, 2H), 2.08 (s, C.sup.1H, 3H), 1.74 (m, C.sup.3H, 2H), 1.15 (s, C.sup.5,6H, 6H).

COMPARATIVE EXAMPLE 9A

Uncatalysed, Solvent-Free Michael Reaction of 2-cyclohexen-1-one and (1-methoxy-2-methylprop-1-enyloxy)-trimethylsilane

[0208] ##STR00010##

[0209] 2-Cyclohexen-1-one (0.533 g, 5.545 mmol) and (1-methoxy-2-methylprop-1-enyloxy)trimethylsilane (1.05 g, 6.029 mmol) are mixed in a 50 ml two-necked flask and stirred at room temperature. The reaction solution is investigated by .sup.1H-NMR spectroscopy and then stirred at room temperature for 24 hours. The reaction solution is subsequently investigated again by .sup.1H-NMR spectroscopy, with no change being evident.

[0210] The compounds detected at the endpoint with reference to the .sup.1H-NMR spectrum are the unchanged starting materials (1-methoxy-2-methylprop-1-enyloxy)trimethylsilane and 2-cyclohexen-1-one having the following shift values.

[0211] (1-Methoxy-2-methylprop-1-enyloxy)trimethylsilane:

[0212] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 3.48 (s, C.sup.2H, 3H), 1.55 (s, C.sup.3H, 3H), 1.51 (s, C.sup.4H, 3H), 0.20 (s, C.sup.4H, 9H).

[0213] 2-Cyclohexen-1-one:

[0214] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 7.06 (m, C.sup.2H, 1H), 5.93 (d, C.sup.1H, 1H), 2.36 (m, C.sup.3,5H, 4H), 1.99 (m, C.sup.4H, 2H).

EXAMPLE 9B

Solvent-Free Michael Reaction of 2-cyclohexen-1-one and (1-methoxy-2-methylprop-1-enyloxy)trimethylsilane Catalysed by iron(II) tris[hydrogen(pentafluoroethyl)phosphonate] (2 mol %)

[0215] Iron(III) tris[hydrogen(pentafluoroethyl)phosphonate], Fe[(C.sub.2F.sub.5)P(O).sub.2OH].sub.3 (0.139 g, 0.21 mmol) is dissolved in 2-cyclohexen-1-one (1.03 g, 10.66 mmol) in a 50 ml two-necked flask with reflux condenser and drying tube. (1-Methoxy-2-methylprop-1-enyloxy)trimethylsilane (1.87 g, 10.71 mmol) is added to this solution. After a reaction time of 24 hours, a conversion of 52 mol % can be determined by .sup.1H-NMR spectroscopy. 30 ml of water are added to the reaction mixture, which is then extracted with 30 ml of dichloromethane. The organic phase is separated off, and the dichloromethane is removed in vacuo at 0.1 Pa and room temperature, giving methyl 2-methyl-2-(3-oxocyclohexyl)propanoate (1.08 g, 5.442 mmol, 51% of the theoretical yield) as a white solid.

[0216] Methyl 2-methyl-2-(3-oxocyclohexyl)propanoate:

[0217] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 3.63 (s, C.sup.8H, 3H), 2.37 (m, C.sup.1,4,5,5H, 4H), 2.01 (s, C.sup.1,2H, 2H), 1.86 (m, C.sup.2H, 1H), 1.54 (m, C.sup.3H, 1H), 1.30 (m, C.sup.3H, 1H), 1.15 (s, C.sup.6H, 3H), 1.16 (s, C.sup.7H, 3H).

[0218] 1H-NMR (CDCl.sub.3; in ppm): 3.68 (s, 3H), 2.43-1.96 (m, 6H), 1.84-1.71 (m, 1H), 1.68-1.50 (m, 1H), 1.46-1.30 (m, 1H), 1.17 (s, 3H), 1.15 (s, 3H).]

[0219] The NMR spectra correspond to the literature data [R. Nagase, J. Osada, H. Tamagaki, Y. Tanabe, Adv. Synth. Catal. 2010, vol. 352, pp. 1128-1134].

EXAMPLE 9C

Solvent-Free Michael Reaction of 2-cyclohexen-1-one and (1-methoxy-2-methylprop-1-enyloxy)trimethylsilane Catalysed by iron(II) tris[hydrogen(pentafluoroethyl)phosphonate] (10 mol %)

[0220] Iron(III) tris[hydrogen(pentafluoroethyl)phosphonate], Fe[(C.sub.2F.sub.5)P(O).sub.2OH].sub.3 (0.161 g, 0.247 mmol) is dissolved in 2-cyclohexen-1-one (0.239 g, 2.486 mmol) in a 50 ml two-necked flask with reflux condenser and drying tube. (1-Methoxy-2-methylprop-1-enyloxy)trimethylsilane (0.469 g, 2.691 mmol) is added to this solution. After a reaction time of 24 hours, a conversion of 69 mol % can be determined by means of .sup.1H-NMR spectroscopy. 30 ml of water are added to the reaction mixture, which is then extracted three times with 10 ml of n-hexane. The organic phases are in each case separated off, combined, and the n-hexane is removed at 0.1 Pa and room temperature. Methyl 2-methyl-2-(3-oxocyclohexyl)propanoate (0.245 g, 1.236 mmol, 50% of the theoretical yield) is isolated as a white solid. The product is characterised by means of .sup.1H-NMR spectroscopy. The chemical shifts and coupling values correspond to the shift values indicated in Example 9b.

COMPARATIVE EXAMPLE 10A

Uncatalysed, Solvent-Free Michael Reaction of methyl vinyl ketone and acetylacetone

[0221] ##STR00011##

[0222] Methyl vinyl ketone (0.511 g, 7.291 mmol) and acetylacetone (0.785 g, 7.841 mmol) are mixed in a 50 ml two-necked flask and stirred at room temperature. After a reaction time of 24 hours, a conversion of 75% can be determined by .sup.1H-NMR spectroscopy. The compounds detected at the end point with reference to the .sup.1H-NMR spectrum are acetylacetone, methyl vinyl ketone, 3-acetylheptane-2,6-dione (keto form) and 3-(1-hydroxyethylidene)heptane-2,6-dione (enol form) having the following shift values. The ratio of methyl vinyl ketone to the tautomers 3-acetylheptane-2,6-dione (keto form) and 3-(1-hydroxyethylidene)heptane-2,6-dione (enol form) is 25:55:20.

##STR00012##

[0223] Acetylacetone (keto/enol form):

[0224] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 2.04 (m, enol CH.sub.3, 6H), 2.17 (s, keto CH.sub.3, 6H), 3.62 (s, enol CH, 1H), 5.65 (s, keto CH, 1H), 15.61 (s, enol OH, 1H).

[0225] Methyl vinyl ketone:

[0226] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 6.28 (m, C.sup.2,3H, 2H), 5.94 (d, .sup.3J.sub.H,H=10.1 Hz, C.sup.3H, 1H), 2.26 (s, C.sup.1,1H, 6H).

[0227] 3-Acetylheptane-2,6-dione (keto form):

[0228] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 3.76 (t, .sup.3J.sub.H,H=6 Hz, C.sup.2H, 1H), 2.43 (t, .sup.3J.sub.H,H=6.0 Hz, C.sup.3H, 2H), 2.07 (s, C.sup.1,6H, 6H), 2.04 (m, C.sup.5H, 3H), 2.00 (m, C.sup.4H, 2H).

[0229] The NMR spectra correspond to the literature data [M. Picquet, C. Bruneau, P. H. Dixneuf, Tetrahedron, 1999, vol. 55, p. 3937]:

[0230] .sup.1H-NMR (solvent: CDCl.sub.3, in ppm): 3.62 (t, .sup.3J.sub.H,H=7 Hz, 1H), 2.33 (t, .sup.3J.sub.H,H=7 Hz, 2H), 2.07 (s, 6H), 2.00 (s, 3H) 2.05-1.87 (m, 2H).]

[0231] 3-(1-Hydroxyethylidene)heptane-2,6-dione (enol form)

[0232] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 16.83 (s, OH, 1H), 2.53 (dm, C.sup.3H, 2H), 2.22 (dm, C.sup.2H, 2H), 2.16 (s, C.sup.4,5H, 6H), 2.13 (s, C.sup.1H, 3H).

[0233] The NMR spectra correspond to the literature data [C. Allais, F. Liby-Muller, J. Rodriguez, T. Constantieux, Eur. J. Org. Chem., 2013, pp. 4131-4145]: .sup.1H-NMR data for both tautomers; solvent: CDCl.sub.3, in ppm: 15.73 (br s, 1H), 3.61 (t, J=6.9 Hz, 1H), 2.50-2.45 (m, 2H), 2.37 (d, J=7.1 Hz, 2H), 2.11 (s, 9H), 2.09 (s, 3H), 2.06 (s, 3H), 2.04 (s, 3H), 2.02-1.95 (m, 4H).

EXAMPLE 10B

Solvent-Free Michael Reaction of methyl vinyl ketone with acetylacetone Catalysed by iron(III) tris[hydrogen(pentafluoroethyl)phosphonate] (10 mol %)

[0234] Iron(III) tris[hydrogen(pentafluoroethyl)phosphonate], Fe[C.sub.2F.sub.5P(O).sub.2OH].sub.3 (0.252 g, 0.386 mmol), is initially introduced in a 50 ml two-necked flask, and methyl vinyl ketone (0.279 g, 3.981 mmol) and acetylacetone (0.617 g, 6.163 mmol) are subsequently added and the mixture is stirred at room temperature. After a reaction time of 5 minutes, complete conversion of methyl vinyl ketone into the product can be detected by means of .sup.1H-NMR spectroscopy.

[0235] The compounds detected at the end point with reference to the .sup.1H-NMR spectrum are acetylacetone, 3-acetylheptane-2,6-dione (keto form) and 3-(1-hydroxyethylidene)heptane-2,6-dione (enol form) with the shift values indicated in Example 9a. The ratio of the tautomers 3-acetylheptane-2,6-dione (keto form) and 3-(1-hydroxyethylidene)heptane-2,6-dione (enol form) is 65:35.

EXAMPLE 10C

Solvent-Free Michael Addition of methyl vinyl ketone and acetylacetone Catalysed by iron(III) tris[hydrogen(pentafluoroethyl)-phosphonate] (2 mol %)

[0236] Iron(III) tris[hydrogen(pentafluoroethyl)phosphonate], Fe[C.sub.2F.sub.5P(O).sub.2OH].sub.3 (0.063 g, 0.097 mmol), is initially introduced in a 50 ml two-necked flask, and methyl vinyl ketone (0.360 g, 5.136 mmol) and acetylacetone (0.779 g, 7.781 mmol) are subsequently added, and the mixture is stirred at room temperature. After a reaction time of one hour, complete conversion of methyl vinyl ketone to the product can be detected by means of .sup.1H-NMR spectroscopy.

[0237] The compounds detected at the end point with reference to the .sup.1H-NMR spectrum are acetylacetone, 3-acetylheptane-2,6-dione (keto form) and 3-(1-hydroxyethylidene)heptane-2,6-dione (enol form) having the shift values indicated in Example 9a. The ratio of the tautomers 3-acetylheptane-2,6-dione (keto form) and 3-(1-hydroxyethylidene)heptane-2,6-dione (enol form) is 67:33.

EXAMPLE 10D

Reaction from Example 10c with a Larger Excess of Acetylacetone

[0238] Iron(III) tris[hydrogen(pentafluoroethyl)phosphonate], Fe[C.sub.2F.sub.5P(O).sub.2OH].sub.3 (0.102 g, 0.156 mmol), is initially introduced in a 50 ml two-necked flask, and methyl vinyl ketone (0.582 g, 8.304 mmol) and acetylacetone (1.93 g, 19.317 mmol) are subsequently added, and the mixture is stirred at room temperature. After a reaction time of four hours, complete conversion of methyl vinyl ketone to the product can be detected by means of .sup.1H-NMR spectroscopy.

[0239] The compounds detected at the end point with reference to the .sup.1H-NMR spectrum are acetylacetone, 3-acetylheptane-2,6-dione (keto form) and 3-(1-hydroxyethylidene)heptane-2,6-dione (enol form) having the shift values indicated in Example 9a. Increasing the amount of acetylacetone to 2.5 times the amount enables a ratio of the tautomers 3-acetylheptane-2,6-dione (keto form) and 3-(1-hydroxyethylidene)heptane-2,6-dione (enol form) of 53:47 to be obtained.

COMPARATIVE EXAMPLE 11A

Uncatalysed, Solvent-Free Michael Reaction of 2-cyclohexen-1-one and acetylactetone

[0240] ##STR00013##

[0241] 2-Cyclohexen-1-one (0.571 g, 5.940 mmol) and acetylacetone (0.664 g, 6.632 mmol) are combined in a 50 ml two-necked flask. The reaction solution is investigated by .sup.1H-NMR spectroscopy and then stirred at room temperature for 24 hours. The reaction solution is then investigated again by .sup.1H-NMR spectroscopy, with no change being evident.

[0242] The compounds detected at the end point with reference to the .sup.1H-NMR spectrum are the unchanged starting materials acetylacetone and 2-cyclohexen-1-one having the following shift values.

[0243] Acetylacetone (keto/enol form):

[0244] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 2.04 (m, enol CH.sub.3, 6H), 2.16 (s, keto CH.sub.3, 6H), 3.62 (s, enol CH, 1H), 5.63 (s, keto CH, 1H), 15.62 (s, enol OH, 1H).

[0245] 2-Cyclohexen-1-one:

[0246] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 7.06 (dt, .sup.3J.sub.H,H=10.1 Hz, .sup.3J.sub.H,H=4.1 Hz, C.sup.2H, 1H), 5.93 (dt, C.sup.1H, .sup.3J.sub.H,H=10.1 Hz, .sup.4J.sub.H,H=1.9 Hz, 1H), 2.36 (m, C.sup.3,5H, 4H), 2.00 (m, C.sup.4H, 2H).

EXAMPLE 11B

Solvent-Free Michael Reaction of 2-cyclohexen-1-one and acetylacetone Catalysed by iron(III) tris[hydrogen(pentafluoroethyl)-phosphonate] (2 mol %)

[0247] Iron(III) tris[hydrogen(pentafluoroethyl)phosphonate], Fe[C.sub.2F.sub.5P(O).sub.2OH].sub.3 (0.089 g, 0.136 mmol), is initially introduced in a 50 ml two-necked flask, and 2-cyclohexen-1-one (0.658 g, 6.845 mmol) and acetylacetone (1.37 g, 13.654 mmol) are subsequently added, and the mixture is stirred at room temperature. After 3 days, a conversion of 97 mol % from 2-cyclohexen-1-one to 3-(3-oxocyclohexyl)pentane-2,4-dione can be determined by .sup.1H-NMR. The acetylacetone is removed from the reaction mixture at room temperature and 0.1 Pa. Extraction with n-hexane (1010 ml) enables 3-(3-oxocyclohexyl)pentane-2,4-dione (0.456 g, 2.325 mmol, 34% of the theoretical yield) to be obtained as colourless crystals, having the following shift values:

[0248] 3-(3-Oxocyclohexyl)pentane-2,4-dione:

[0249] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 1.44 (m, 1H), 1.66 (m, 2H), 2.02 (m, 1H), 2.15 (m, 1H), 2.29 (m, 2H), 2.55 (m, 1H), 3.85 (d, .sup.3J.sub.H,H=9.5 Hz, 1H). GC-MS: tR 7.11 min, MS (m/z) (rel. abund.): 196 (M+) (1), 153 (52), 136 (8), 125 (12), 111 (52), 97 (100), 85 (24), 68 (20), 55 (16), 43 (100).

[0250] The NMR spectrum corresponds to the literature data [A. Oge, M. E. Mavis, C. Yolacan, F. Aydogan, Turk. J. Chem., 2012, vol. 36, p. 137]:

[0251] .sup.1H-NMR (solvent: CDCl.sub.3; in ppm): 1.30-1.40 (m, 1H, CH.sub.2), 1.62-1.74 (m, 1H, CH.sub.2), 1.75-1.82 (m, 1H, CH.sub.2), 1.98-2.06 (m, 2H, CH.sub.2), 2.14 (s, 3H, CH.sub.3), 2.16 (s, 3H, CH.sub.3), 2.20-2.31 (m, 2H, CH.sub.2), 2.35-2.41 (m, 1H, CH.sub.2), 2.61-2.71 (m, 1H, CHCH.sub.2), 3.61 (d, J=10.4 Hz, 1H, CH(COCH.sub.3).sub.2).

[0252] GC-MS: tR 18.08 min, MS (m/z) (rel. abund.): 196 (M+) (1), 153 (43), 111 (23), 97 (57), 43 (100).]

COMPARATIVE EXAMPLE 12A

Uncatalysed Friedel-Crafts Acylation of Anisole Using Acetic Anhydride

[0253] ##STR00014##

[0254] Nitromethane (7.68 g, 0.125 mol) and anisole (0.350 g, 3.237 mmol) are stirred in a 50 ml two-necked flask at an oil-bath temperature of 80 C. for 4.5 h. Conversion to bis(p-methoxyphenyl)methane cannot be determined by .sup.1H-NMR spectroscopy. In the next step, acetic anhydride (0.462 g, 4.490 mmol) is added to the reaction solution. The reaction solution is investigated by .sup.1H-NMR spectroscopy and then stirred at an oil-bath temperature of 80 C. for 4.5 hours. The reaction solution is subsequently investigated again by .sup.1H-NMR spectroscopy, with no change being evident. The compounds detected at the end point with reference to the .sup.1H-NMR spectrum are the unchanged starting materials acetic anhydride, anisole and nitromethane having the following shift values.

[0255] Acetic anhydride:

[0256] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 2.17 (s, C.sup.1H, 6H).

[0257] Anisole:

[0258] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 7.32 (m, C.sup.3,3,4H, 3H), 6.96 (m, C.sup.2,2H, 2H), 3.80 (s, C.sup.1H, 3H).

[0259] Nitromethane:

[0260] .sup.1H-NMR (solvent: CD.sub.3CN; in ppm): 4.33 (s, C.sup.1H, 3H).

EXAMPLE 12B

Friedel-Crafts Acylation of Anisole Using acetic anhydride Catalysed by iron(III) tris[hydrogen(pentafluoroethyl)-phosphonate] (20 mol %)

[0261] Iron(III) tris[hydrogen(pentafluoroethyl)phosphonate], Fe[(C.sub.2F.sub.5)P(O).sub.2OH](0.384 g, 0.588 mmol), and nitromethane (8.07 g) are combined with anisole (0.326 g, 3.015 mmol) and acetic anhydride (0.614 g, 6.014 mmol) in a 50 ml two-necked flask and stirred at an oil-bath temperature of 80 C. for 90 minutes. The conversion is determined by .sup.1H-NMR spectroscopy and is 99 mol %. The solvent nitromethane is removed from the reaction mixture at 0.1 Pa and room temperature. 20 ml of a 5% NaHCO.sub.3 solution are added to the reaction mixture. The product is extracted with diethyl ether (310 ml). The combined ether phases are evaporated to dryness at room temperature and 0.1 Pa and subsequently extracted twice with 10 ml of n-hexane. Evaporation of the combined hexane phases to dryness at 0.1 Pa and room temperature gives 4-methoxyacetophenone, (0.311 g, 2.071 mmol, 68.7% of the theoretical yield) as a white solid. The product contains 5% of bis(p-methoxyphenyl)methane) impurity. 4-Methoxyacetophenone:

[0262] .sup.1H-NMR (solvent: CDCl.sub.3; in ppm): 7.96 (m, C.sup.2,2H, 2H), 7.02 (m, C.sup.3,3H, 2H), 3.88 (s, C.sup.1H, 3H), 2.53 (s, C.sup.4,4H, 3H).

[0263] .sup.13C-NMR (solvent: CDCl.sub.3; in ppm): 196.8, 163.59, 130.6, 130.4, 113.7, 55.5, 26.3.

[0264] The NMR spectra correspond to the data given in the literature [Qian, Adv. Synth. Catal., 2012, vol. 354, p. 3231]:

[0265] .sup.1H NMR (300 MHz, CDCl.sub.3) : 7.92 (d, J=6.6 Hz, 2H), 6.91 (d, J=6.6 Hz, 2H), 3.85 (s, 3H), 2.54 (s, 3H); .sup.13C NMR (100 MHz, CDCl.sub.3) : 196.74, 163.37, 130.49, 130.19, 113.57, 55.37, 26.26]

[0266] Bis(p-methoxyphenyl)methane

[0267] .sup.1H-NMR (solvent: CDCl.sub.3; in ppm): 7.14 (dm, .sup.3J.sub.H,H=8.4 Hz, C.sup.2,2,2,2H, 4H), 6.85 (dm, .sup.3J.sub.H,H=8.4 Hz, C.sup.3,3,3,3H, 4H), 3.89 (s, C.sup.1H, 2H), 3.76 (s, C.sup.4,4H, 6H).

[0268] .sup.13C-NMR (solvent: CDCl.sub.3; in ppm): 157.9, 133.7, 129.7, 113.8, 55.2, 40.1. The NMR spectra correspond to the data given in the literature [Chen, Tetrahedron, 2014, vol. 70, p. 1975].

[0269] .sup.1H NMR (300 MHz, CDCl.sub.3) 7.11 (d, J=8.5 Hz, 4H), 6.84 (d, J=8.6 Hz, 4H), 3.89 (s, 2H), 3.80 (s, 6H).

EXAMPLE 12C

Friedel-Crafts Acylation of Anisole Using acetic anhydride Catalysed by iron(III) tris[hydrogen(pentafluoroethyl)-phosphonate] (5 mol %)

[0270] Iron(III) tris[hydrogen(pentafluoroethyl)phosphonate], Fe[(C.sub.2F.sub.5)P(O).sub.2OH](0.099 g, 0.152 mmol), and nitromethane (8.00 g) are combined with anisole (0.328 g, 3.033 mmol) and acetic anhydride (0.619 g, 6.063 mmol) in a 50 ml two-necked flask and stirred at an oil-bath temperature of 80 C. for three hours. The conversion to 4-methoxyacetophenone determined by .sup.1H-NMR spectroscopy is 81.7 mol %. The compounds detected at the end point with reference to the .sup.1H-NMR spectrum are 4-methoxyacetophenone, bis(p-methoxyphenyl)methane), acetic anhydride, acetic acid, anisole and nitromethane having the shift values indicated in Example 12a and Example 12b. The molar ratio of anisole to 4-methoxyacetophenone to bis(p-methoxyphenyl)methane is 21.7:75.3:1. 20 ml of H.sub.2O and 20 ml of n-hexane are added to the reaction mixture. On addition of n-hexane, three liquid phases form. The product is extracted with four further 20 ml portions of n-hexane. The n-hexane phase is separated off in each case. The five n-hexane phases are combined and evaporated to dryness at room temperature and 0.1 Pa, giving 4-methoxyacetophenone (0.244 g, 1.624 mmol) as a white solid. 20 ml of chloroform are added to the remaining phases which have already been extracted with n-hexane. The organic phase is separated off and evaporated to dryness at 0.1 Pa and room temperature. Re-extraction with 20 ml of n-hexane and evaporation to dryness enables further 4-methoxyacetophenone (0.079 g, 0.526 mmol) to be obtained as a white solid. The total yield is 0.323 g (2.151 mmol, 71% of the theoretical yield) of 4-methoxyacetophenone (4.5% of bis(p-methoxyphenyl)methane) impurity having the shift values indicated in Example 12b.

EXAMPLE 12D

Friedel-Crafts Acylation of Anisole Using acetic anhydride Catalysed by iron(III) tris[hydrogen(pentafluoroethyl)-phosphonate] (2 mol %)

[0271] Anisole (0.325 g, 3.005 mmol) and acetic anhydride (0.646 g, 6.328 mmol) are added to 0.039 g (0.060 mmol) of iron(III) tris[hydrogen(pentafluoroethyl)phosphonate], Fe[(C.sub.2F.sub.5)P(O).sub.2OH].sub.3, in nitromethane (8.099 g) in a 50 ml two-necked flask and the mixture is stirred at an oil-bath temperature of 80 C. for 4 hours. The conversion to 4-methoxyacetophenone subsequently determined by .sup.1H-NMR spectroscopy is 77 mol %. The compounds detected at the end point with reference to the .sup.1H-NMR spectrum are 4-methoxyacetophenone, bis(p-methoxyphenyl)methane), acetic anhydride, acetic acid, anisole and nitromethane having the shift values indicated in Example 12b. The molar ratio of anisole to 4-methoxyacetophenone to bis(p-methoxyphenyl)methane) is 22.8:77.8:2.4. 20 ml of H.sub.2O are added to the reaction mixture. The product is extracted with chloroform (310 ml).

[0272] The combined chloroform phases are evaporated to dryness at room temperature and 0.1 Pa. 4-Methoxyacetophenone (0.298 g, 1.984 mmol, 66% of the theoretical yield) is isolated as a colourless solid and has the shift values indicated in the .sup.1H-NMR spectrum in Example 12b (the product contains 7% of bis(p-methoxyphenyl)methane) impurity.

EXAMPLE 12E

Reaction from Example 12b with Reversed Sequence of the Addition of the Starting Materials

[0273] Acetic anhydride 0.646 g (6.328 mmol) and anisole 0.328 g (3.033 mmol) are added to a suspension of iron(III) tris[hydrogen(pentafluoroethyl)-phosphonate], Fe[(C.sub.2F.sub.5)P(O).sub.2OH].sub.3 (0.391 g, 0.599 mmol), in nitromethane (8.40 g) in a 50 ml two-necked flask, and the mixture is stirred at an oil-bath temperature of 80 C. for 90 minutes. The conversion to 4-methoxyacetophenone determined by .sup.1H-NMR spectroscopy is 99 mol %. 20 ml of H.sub.2O are added to the reaction mixture. The product is extracted with 520 ml of n-hexane. The combined n-hexane phases are evaporated to dryness at room temperature and 0.1 Pa. 4-Methoxyacetophenone (0.297 g, 1.978 mmol, 65.2% of the theoretical yield), is isolated as a colourless solid and has the shift values indicated in the .sup.1H-NMR spectrum in Example 12b. By changing the sequence of addition of the starting materials, the formation of bis(p-methoxyphenyl)methane is prevented.

COMPARATIVE EXAMPLE 13A

Uncatalysed Methanolysis of Octyl Acetate

[0274] ##STR00015##

[0275] Methanol (0.5 ml) is added to 1-octyl acetate (0.043 ml, 0.290 mmol) in an NMR tube. The reaction solution is investigated by .sup.1H-NMR spectroscopy and then stirred at an oil-bath temperature of 50 C. for 24 hours. The reaction solution is subsequently investigated again by .sup.1H-NMR spectroscopy. The conversion determined after a reaction time of 24 hours is less than 1%.

[0276] The compounds detected at the end point with reference to the .sup.1H-NMR spectrum are: 1-octanol, octyl acetate, methyl acetate and methanol having the following shift values, but principally octyl acetat. The molar ratio of octyl acetate to octanol is: 1232:1.

[0277] 1-Octanol:

[0278] .sup.1H-NMR (solvent: CD.sub.3OD; in ppm): 4.70 (s, OH, 1H)*, 3.57 (t, .sup.3J.sub.H,H=6.6 Hz, C.sup.1H, 2H), 1.56 (m, C.sup.2H, 2H), 1.36 (m, C.sup.3,45,67H, 10H), 0.94 (m, C.sup.8H, 3H).

[0279] 1-Octyl acetate:

[0280] .sup.1H-NMR (solvent: CD.sub.3OD; in ppm): 4.10 (t, .sup.3J.sub.H,H=6.6 Hz, C2H, 2H), 2.08 (s, C.sup.1H, 3H), 1.67 (m, C.sup.3H, 2H), 1.36 (m, C.sup.4,5,6,7,8, 10H), 0.94 (m, C.sup.9H, 3H).

[0281] Methyl acetate:

[0282] .sup.1H-NMR (solvent: CD.sub.3OD; in ppm): 3.35 (s, C.sup.2H, 3H)*, 2.07 (m, C.sup.1H, 3H).

[0283] Methanol:

[0284] .sup.1H-NMR (solvent: CD.sub.3OD; in ppm): 4.70 (s, OH, 1H)*, 3.33 (s, CH, 3H)* *(residual protons from the CD.sub.3OD used are detected:

EXAMPLE 13B

Methanolysis of octyl acetate Catalysed by yttrium(III) tris[hydrogen(pentafluoroethyl)phosphonate] (10 mol %)

[0285] Yttrium(III) tris[hydrogen(pentafluoroethyl)phosphonate], Y[(C.sub.2F.sub.5).sub.2P(O).sub.2OH].sub.3 (3.11 mg*, 0.00453 mmol), is dissolved in CD.sub.3OD (0.5 ml). Octyl acetate (0.009, ml, 0.290 mmol) is added, and the reaction mixture is stirred at room temperature. The conversion determined by .sup.1H-NMR spectroscopy is 12 mol % after a reaction time of 24 hours. *(Balance: KERN ABT 220-5DM; max=220/82 g; d=0.1 mg/0.01 mg) The compounds detected at the end point with reference to the .sup.1H-NMR spectrum are: 1-octanol, octyl acetate, methyl acetate and methanol having the shift values indicated in Example 13a.

EXAMPLE 13C

Reaction from Example 13b at 50 C.

[0286] Yttrium(III) tris[hydrogen(pentafluoroethyl)phosphonate], Y[(C.sub.2F.sub.5).sub.2P(O).sub.2OH].sub.3 (7.55 mg*, 0.011 mmol), is dissolved in CD.sub.3OD (0.5 ml). Octyl acetate (0.022 ml, 0.110 mmol) is added, and the reaction mixture is stirred at an oil-bath temperature of 50 C. The conversion determined by .sup.1H-NMR spectroscopy is 65 mol % after a reaction time of 24 hours. *(Balance: KERN ABT 220-5DM; max=220/82 g; d=0.1 mg/0.01 mg)

[0287] The compounds detected at the end point with reference to the .sup.1H-NMR spectrum are: 1-octanol, octyl acetate, methyl acetate and methanol having the shift values indicated in Example 13a.

EXAMPLE 14

Synthesis of 1-(4-ethoxyphenyl)propan-1-one by reaction of ethoxybenzene with propionic anhydride, Catalysed by Al[C.SUB.2.F.SUB.5.P(O).SUB.2.OH].SUB.3 .(5 mol %)

[0288] Aluminium(III) tris(pentafluoroethylhydrogenphosphonate) (0.312 g, 0.05 mmol) is dissolved in propionic anhydride (1.65 g, 12.7 mmol) in a 50 ml two-necked flask with reflux condenser. A clear solution is present. Ethoxybenzene (1.222 g, 10 mmol) is added, and the solution is stirred at 70 C. (temperature in the solution) for 2 h. The conversion of ethoxybenzene determined by .sup.1H-NMR spectroscopy is 74%.

[0289] NMR (solvent: CD.sub.3CN; in ppm):

[0290] .sup.1H NMR: 7.91 (m, 2H, CH), 6.94 (m, 2H, CH), 4.08 (q, .sup.3J.sub.H,H=7.0 Hz, 2H, OCCH.sub.2), 2.94 (q, .sup.3J.sub.H,H=7.3 Hz, 2H, OCCH.sub.2), 1.37 (t, .sup.3J.sub.H,H=7.0 Hz, 3H, CH.sub.3), 1.07 (t, .sup.3J.sub.H,H=7.6 Hz, 3H, CH.sub.3).