BISMUTH-CONTAINING CATALYST COMPRISING AT LEAST ONE AROMATIC SUBSTITUENT

Abstract

Described herein is a bismuth-containing catalyser, which is defined by a general formula (I). The bismuth-containing catalyser includes at least one radical R1, which includes a carboxyl fragment according to the general formula (II), where a first carbon atom (α-carbon) is bonded to the carbon atom of the carboxyl group, which in turn is directly substituted with at least one aromatic system. Also described herein is a method for preparing the bismuth-containing catalyser and a method of using the bismuth-containing catalyser for preparing compounds including a urethane group.

Claims

1. A bismuth-containing catalyser of a general formula (I)
((R.sup.1).sup.−).sub.x((R.sup.2).sup.−).sub.y((X).sup.−).sub.z(Bi).sup.3+  (I) in which the variables are defined as follows: R.sup.1 is mutually independently a radical of a general formula (II) ##STR00009## and x is 1, 2 or 3; R.sup.2 is mutually independently a radical of a general formula (III) ##STR00010## and y is 0, 1 or 2; X is mutually independently hydroxyl, halogen, carbonate, hydrogencarbonate or R.sup.7 and z is 0, 1 or 2; wherein the sum total of x, y and z is equal to 3; R.sup.3 is unsubstituted or at least monosubstituted C.sub.1-C.sub.30-alkyl, C.sub.6-C.sub.14-aryl or C.sub.7-C.sub.30-aralkyl, wherein the substituents are selected from the group consisting of hydroxyl, halogen, carboxyl, —CF.sub.3, —NH.sub.2, C.sub.1-C.sub.6-alkoxy, C.sub.1-C.sub.30-alkyl and C.sub.6-C.sub.14-aryl and the alkyl and aryl fragments of these substituents may in turn be at least monosubstituted by hydroxyl, halogen, —CF.sub.3, —NH.sub.2 or C.sub.1-C.sub.6-alkoxy, and wherein the carbon atom of the radical R.sup.3 bonded directly to the carbon atom of the carboxyl group of the general formula (III) does not comprise any unsubstituted or at least monosubstituted C.sub.6-C.sub.14-aryl as substituent. R.sup.4, R.sup.5 and R.sup.6 are mutually independently unsubstituted or at least monosubstituted C.sub.1-C.sub.30-alkyl, C.sub.6-C.sub.14-aryl or C.sub.7-C.sub.30-aralkyl, wherein the substituents are selected from the group consisting of hydroxyl, halogen, carboxyl, —CF.sub.3, —NH.sub.2, C.sub.1-C.sub.6-alkoxy, C.sub.1-C.sub.30-alkyl and C.sub.6-C.sub.14-aryl and the alkyl and aryl fragments of these substituents may in turn be at least monosubstituted by hydroxyl, halogen, —CF.sub.3, —NH.sub.2 or C.sub.1-C.sub.6-alkoxy, and wherein at least one of the radicals R.sup.4, R.sup.5 or R.sup.6 is unsubstituted or at least monosubstituted C.sub.6-C.sub.14-aryl, R.sup.7 is unsubstituted or at least monosubstituted C.sub.1-C.sub.3N-alkyl, C.sub.6-C.sub.14-aryl or C.sub.7-C.sub.30-aralkyl, wherein the substituents are selected from the group consisting of hydroxyl, halogen, carboxyl, —CF.sub.3, —NH.sub.2, C.sub.1-C.sub.6-alkoxy, C.sub.1-C.sub.30-alkyl and C.sub.6-C.sub.14-aryl and the alkyl and aryl fragments of these substituents may in turn be at least monosubstituted by hydroxyl, halogen, —CF.sub.3, —NH.sub.2 or C.sub.1-C.sub.6-alkoxy.

2. The bismuth-containing catalyser as claimed in claim 1, wherein i) R.sup.4, R.sup.5 and R.sup.6 are mutually independently unsubstituted or at least monosubstituted C.sub.1-C.sub.12-alkyl or C.sub.6-C.sub.14-aryl, wherein the substituents are selected from the group consisting of hydroxyl, chlorine, —CF.sub.3 and C.sub.1-C.sub.6-alkyl, and wherein at least one of the radicals R.sup.4, R.sup.5 or R.sup.6 is unsubstituted or at least monosubstituted C.sub.6-C.sub.14-aryl, and/or ii) R.sup.3 is unsubstituted or at least monosubstituted C.sub.1-C.sub.12-alkyl, wherein the substituents are selected from the group consisting of hydroxyl, chlorine and —CF.sub.3, and/or iii) X is hydroxyl, chlorine or R.sup.7 and R.sup.7 is unsubstituted or at least monosubstituted C.sub.1-C.sub.12-alkyl or C.sub.6-C.sub.14-aryl, wherein the substituents are selected from the group consisting of hydroxyl, chlorine, —CF.sub.3 and C.sub.1-C.sub.6-alkyl.

3. The bismuth-containing catalyser as claimed in claim 1, wherein i) x is equal to 2 or 3, y is equal to 0 or 1 and z is equal to 0 or 1, or ii) x is equal to 3 and y and z are each equal to 0, or iii) x is equal to 2, y is equal to 0 and z is equal to 1, or iv) x is equal to 2, y is equal to 1 and z is equal to 0.

4. The bismuth-containing catalyser as claimed in claim 1, wherein i) R.sup.4 is unsubstituted or at least monosubstituted phenyl, wherein the substituents are selected from the group consisting of hydroxyl, chlorine, —CF.sub.3 and C.sub.1-C.sub.6-alkyl, ii) R.sup.5 is unsubstituted or at least monosubstituted phenyl or C.sub.1-C.sub.12-alkyl, wherein the substituents are selected from the group consisting of hydroxyl, chlorine, —CF.sub.3 and C.sub.1-C.sub.6-alkyl, and iii) R.sup.6 is unsubstituted or at least monosubstituted phenyl or C.sub.1-C.sub.12-alkyl, wherein the substituents are selected from the group consisting of hydroxyl, chlorine, —CF.sub.3 and C.sub.1-C.sub.6-alkyl.

5. The bismuth-containing catalyser as claimed in claim 1, wherein i) R.sup.4 is unsubstituted or at least monosubstituted phenyl, wherein the substituents are selected from the group consisting of hydroxyl, chlorine, —CF.sub.3 and C.sub.1-C.sub.6-alkyl, ii) R.sup.5 is unsubstituted or at least monosubstituted phenyl or C.sub.1-C.sub.12-alkyl, wherein the substituents are selected from the group consisting of hydroxyl, chlorine, —CF.sub.3 and C.sub.1-C.sub.6-alkyl, iii) R.sup.6 is unsubstituted or at least monosubstituted C.sub.1-C.sub.12-alkyl, wherein the substituents are selected from the group consisting of hydroxyl, chlorine and —CF.sub.3, and iv) x is equal to 3 and y and z are each equal to 0.

6. The bismuth-containing catalyser as claimed in claim 1, wherein i) R.sup.4 and R.sup.5 are each phenyl, ii) R.sup.6 is C.sub.1-C.sub.12-alkyl, and iii) x is equal to 3 and y and z are each equal to 0.

7. The bismuth-containing catalyser as claimed in claim 1, wherein the bismuth-containing catalyser is defined according to a general formula (Ia) ##STR00011## wherein R.sup.4, R.sup.5 and R.sup.6 are mutually independently unsubstituted or at least monosubstituted C.sub.1-C.sub.30-alkyl, C.sub.6-C.sub.14-aryl or C.sub.7-C.sub.30-aralkyl, wherein the substituents are selected from the group consisting of hydroxyl, halogen, carboxyl, —CF.sub.3, —NH.sub.2, C.sub.1-C.sub.6-alkoxy, C.sub.1-C.sub.30-alkyl and C.sub.6-C.sub.14-aryl and the alkyl and aryl fragments of these substituents may in turn be at least monosubstituted by hydroxyl, halogen, —CF.sub.3, —NH.sub.2 or C.sub.1-C.sub.6-alkoxy, and wherein at least one of the radicals R.sup.4, R.sup.5 or R.sup.6 is unsubstituted or at least monosubstituted C.sub.6-C.sub.14-aryl.

8. The bismuth-containing catalyser as claimed in claim 7, wherein each of the total of three radicals R.sup.4 are the same, each of the total of three radicals R.sup.5 are the same and each of the total of three radicals R.sup.6 are the same.

9. The bismuth-containing catalyser as claimed in claim 7, wherein i) R.sup.4 is unsubstituted or at least monosubstituted phenyl, wherein the substituents are selected from the group consisting of hydroxyl, chlorine, —CF.sub.3 and C.sub.1-C.sub.6-alkyl, ii) R.sup.5 is unsubstituted or at least monosubstituted phenyl or C.sub.1-C.sub.12-alkyl, wherein the substituents are selected from the group consisting of hydroxyl, chlorine, —CF.sub.3 and C.sub.1-C.sub.6-alkyl, and iii) R.sup.6 is unsubstituted or at least monosubstituted C.sub.1-C.sub.12-alkyl, wherein the substituents are selected from the group consisting of hydroxyl, chlorine and —CF.sub.3.

10. The bismuth-containing catalyser as claimed in claim 7, wherein i) R.sup.4 and R.sup.5 are each phenyl, and ii) R.sup.6 is C.sub.1-C.sub.12-alkyl.

11. A method for preparing a bismuth-containing catalyser of the general formula (I) as claimed in claim 1, comprising reacting i) at least one compound of a general formula (IIa) ##STR00012## or a corresponding salt thereof, wherein R.sup.4, R.sup.5 and R.sup.6 are mutually independently unsubstituted or at least monosubstituted C.sub.1-C.sub.30-alkyl, C.sub.6-C.sub.14-aryl or C.sub.7-C.sub.30-aralkyl, wherein the substituents are selected from the group consisting of hydroxyl, halogen, carboxyl, —CF.sub.3, —NH.sub.2, C.sub.1-C.sub.6-alkoxy, C.sub.1-C.sub.30-alkyl and C.sub.6-C.sub.14-aryl and the alkyl and aryl fragments of these substituents may in turn be at least monosubstituted by hydroxyl, halogen, —CF.sub.3, —NH.sub.2 or C.sub.1-C.sub.6-alkoxy, and wherein at least one of the radicals R.sup.4, R.sup.5 or R.sup.6 is unsubstituted or at least monosubstituted C.sub.6-C.sub.14-aryl, ii) optionally at least one compound of a general formula (IIIa) ##STR00013## or a corresponding salt thereof, wherein R.sup.3 is unsubstituted or at least monosubstituted C.sub.1-C.sub.30-alkyl, C.sub.6-C.sub.14-aryl or C.sub.7-C.sub.30-aralkyl, wherein the substituents are selected from the group consisting of hydroxyl, halogen, carboxyl, —CF.sub.3, —NH.sub.2, C.sub.1-C.sub.6-alkoxy, C.sub.1-C.sub.30-alkyl and C.sub.6-C.sub.14-aryl and the alkyl and aryl fragments of these substituents may in turn be at least monosubstituted by hydroxyl, halogen, —CF.sub.3, —NH.sub.2 or C.sub.1-C.sub.6-alkoxy, and wherein the carbon atom of the radical R.sup.3 bonded directly to the carbon atom of the carboxyl group of the general formula (IIIa) does not comprise any unsubstituted or at least monosubstituted C.sub.6-C.sub.14-aryl as substituent, and iii) at least one bismuth-containing compound selected from the group consisting of Bi.sub.2O.sub.3, bismuth carbonate, bismuth hydrogencarbonate, bismuth halide, Bi(C.sub.6-C.sub.14-aryl).sub.3, Bi(C.sub.1-C.sub.12-alkyl).sub.3 and metallic bismuth.

12. The method as claimed in claim 11, wherein the bismuth-containing compound is selected from the group consisting of Bi.sub.2O.sub.3, BiCl.sub.3, Bi(C.sub.6H.sub.5).sub.3 and metallic bismuth.

13. The method as claimed in claim 11, wherein i) the reaction is carried out under a protective atmosphere and/or in the presence of at least one solvent, and/or ii) the reaction is conducted for at least 10 hours and/or at a temperature of at least 100° C., and/or iii) following the reaction, volatile constituents are removed, the bismuth-containing catalyser is dried under reduced pressure and/or a recrystallization is carried out.

14. The method as claimed in claim 11, wherein a compound of the general formula (IIa) is prepared by reacting a corresponding compound (IIb), but in which R.sup.5 and/or R.sup.6 is H, with a lithium-containing compound, and the intermediate is subsequently reacted with a haloalkane to introduce the radicals R.sup.5 and/or R.sup.6 to obtain a compound according to the general formula (IIa).

15. A method of using the bismuth-containing catalyser as claimed in claim 1, the method comprising using the bismuth-containing catalyser for preparing compounds comprising a urethane group.

16. The bismuth-containing catalyser as claimed in claim 1 wherein x is equal to 3 and y and z are each equal to 0.

17. The bismuth-containing catalyser as claimed in claim 1, wherein R.sup.6 is C.sub.6-C.sub.10-alkyl.

18. The bismuth-containing catalyser as claimed in claim 7, wherein R.sup.6 is C.sub.6-C.sub.10-alkyl.

19. The method as claimed in claim 11, wherein the reaction is carried out under a protective atmosphere and/or in the presence of toluene or tetrahydrofuran.

20. The method as claimed in claim 11, wherein a compound of the general formula (IIa) is prepared by reacting a corresponding compound (IIb), but in which R.sup.5 and/or R.sup.6 is H, with n-butyllithium.

Description

I) PREPARATION OF CATALYSERS ACCORDING TO THE INVENTION

Ia) Precursor of Example 1: 2,2-Diphenyldecanoic Acid (dpdH)

[0107] ##STR00008##

[0108] 2,2-Diphenylacetic acid (10.6 g; 48 mmol) are dissolved in 75 mL of dry tetrahydrofuran (THF) under a protective gas atmosphere (argon or nitrogen) in a 200 mL Schlenk flask and cooled to −15° C. A 1.6M solution of n-butyllithium in hexane (60 mL; 96 mmol) is then added with stirring and over a period of 30 minutes. The reaction solution is stirred at −15° C. for one hour and cooled to −78° C. for the addition of 1-bromooctane (8.3 mL; 48 mmol). Subsequently, the reaction solution is slowly warmed to room temperature and stirred for a further 24 hours.

[0109] For the work-up and purification of the 2,2-diphenyldecanoic acid, a saturated ammonium chloride solution (60 mL) is added to the reaction solution and stirred for 30 minutes. The aqueous phase is separated by means of a separating funnel and extracted with 3×25 mL of diethyl ether. The combined organic phases were dried over magnesium sulfate (MgSO.sub.4). All volatile solvents are then removed under reduced pressure (1.Math.10-3 mbar) and the resulting solid dried at 140° C. under reduced pressure (1.Math.10.sup.−3 mbar) for 24 hours.

[0110] Characterization by .sup.1H-NMR, .sup.13C-NMR, HRMS (high-resolution mass spectrometry), infra-red spectroscopy.

Ib) Catalyser According to Example 1: Bi(2,2-Diphenyldecanoate).SUB.3 .(Bi(dpd).SUB.3.)

[0111] Triphenylbismuth (1.1 g; 2.5 mmol) and 2,2-diphenyldecanoic acid (2.43 g; 7.5 mmol) are initially charged under a protective gas atmosphere in a 25 mL three-necked flask equipped with stirrer bar, reflux condenser, thermometer and protective gas atmosphere inlet (argon or nitrogen). 12.5 mL of dry tetrahydrofuran or dry toluene (5 mL of solvent per 1 mmol of triphenylbismuth) are added to the reactants and the mixture is heated at 110° C. under a protective gas atmosphere for at least 16 hours. The reaction course is monitored by .sup.1H-NMR (nuclear magnetic resonance spectroscopy). After complete conversion of triphenylbismuth with formation of benzene, the reaction is terminated and cooled. All volatile solvents are then removed under reduced pressure (1.Math.10.sup.−3 mbar) and the resulting solid dried at 60° C. under reduced pressure (1.Math.10.sup.−3 mbar) for 24 hours. As required, the resulting compound is purified from toluene and hexane at −40° C. or by recrystallization from hot toluene.

[0112] Characterization by .sup.1H-NMR, .sup.13C-NMR, C/H/N elemental analysis, infra-red spectroscopy.

Ic) Catalyser According to Example 4: Bi(2,2-Diphenylpropionate).SUB.3 .(Bi(dpp).SUB.3.)

[0113] The catalyser Bi(dpp).sub.3 according to example 4 is prepared analogously to the catalyser Bi(dpd).sub.3 described above, in which no synthesis of the precursor is required since the corresponding propionic acid derivative is commercially available (from Sigma-Aldrich), which is reacted with triphenylbismuth to give the inventive catalyser Bi(dpp).sub.3.

II) DETERMINATION OF THE CATALYTIC ACTIVITY OF EXAMPLES 1 TO 5

[0114] The respective catalytic activity of the individual working and comparative examples can be found in Table 1 below. The catalytic activity is tested by means of a reaction in which a compound is formed comprising a urethane group. For this purpose, 11 mmol of 2-ethylhexyl (6-isocyanatohexyl)carbamate (commercially available as Desmodur LD (3.3 mL)) are reacted with 11 mmol of n-butanol (1 mL) as reactants. The reaction was carried out in the presence of a solvent (2 mL of xylene) and the catalysers listed in Table 1 (with a content of 0.1 mol % catalyser based on the amount of bismuth) at a temperature of 60° C.

[0115] The isocyanate decrease and thus the formation of a urethane group are investigated by horizontal ATR-IR spectroscopy. For this purpose, 0.05 mL of the reaction solution are withdrawn at defined time intervals and investigated directly by spectroscopy. The conversion is determined by the relative decrease in intensity of the asymmetrical isocyanate stretching vibration at 2250-2285 cm-1. The starting content of free isocyanate of the reaction solution at room temperature in the absence of catalyser was determined. All IR spectra were normalized to the bands of the symmetrical and asymmetrical stretching vibrations of the CH.sub.2 groups (3000-2870 cm-1).

[0116] The catalysers used are detailed in Table 1.

Example 1: Bi(dpd).sub.3, wherein dpd is 2,2′-diphenyl decanoate
Comparative example 2: DOTL (Dioctyltin dilaurate), commercially available catalyser
Comparative example 3: Bi(neo).sub.3, wherein neo is neodecanoate (commercially available catalyser under the name K-Kat XK651 (King Industries); 50% in neodecanoic acid having a metal content of 23%
Example 4: Bi(dpp).sub.3, wherein dpp is 2,2′-diphenyl propionate
Comparative example 5: without catalyser

TABLE-US-00001 TABLE 1 Bi(neo).sub.3/ No Ex. Bi (dpd).sub.3 Comp. DOTL Comp. XK651 Ex. Bi(dpp).sub.3 Comp. catalyser 1 NCO 2 NCO 3 NCO 4 NCO 5 NCO t/ degra- t/ degra- t/ degra- t/ degra- t/ degra- min dation min dation/% min dation/% min dation/% min dation/% 0 0 0 0 0 0 0 0 0 0 1 43.58 1 58.03 5 18 5 33.14 10 14.5 2 83.97 3 95.6 10 29.11 10 55.9 20 22.15 3 97.800 5 99.6 15 40.77 15 76.92 30 28.04 4 100.000 20 53.12 20 90.11 25 67.135 25 97.5 30 80.04 30 100

[0117] As can be deduced from Table 1, the two catalysers according to the invention show, according to working example 1 and working example 4, a comparable catalytic activity to the known tin-containing catalysers according to comparative example 2. Tin-containing catalysers should be avoided however, owing to their considerable toxicity. The catalytic activity of working examples 1 and 4 is however distinctly improved in comparison to bismuth-containing catalysers according to the prior art (comparative example 3) or conducting the experiment wholly without catalyser (comparative example 5).