NOVEL TERTIARY PHOSPHINES

Abstract: The novel tertiary phosphines according to the present in­ vention are compounds of the general formula wherein R¹ and R² each, independently or taken together, represent an optionally substituted hydrocarbon group; R³ and R⁴ each independently represent a hydrogen atom, an option­ ally substituted hydrocarbon group, a group R⁸-- or a group R⁹-O--, wherein R⁸ and R⁹ each independently represent an optionally substituted hydrocarbon group; R⁵ amd R⁶ each in­ dependently represent a hydroxyl group, in optionally sub­ stituted hydrocarbon group, a group R¹⁰-O-, a group R¹¹--O- or a group wherein R¹⁰, R¹¹, R¹² and R¹³ each inde­ pendently represent an optionally substituted hydrocarbon group, or R⁵ and R⁶ taken together represent an oxygen atom or a group wherein R¹⁴ represents an optionally sub­ stituted hydrocarbon group; and R⁷ represents a hydrogen atom or a group

Description: NOVEL TERTIARY PHOSPHINES The present invention relates to novel tertiary phosphines, to a process for their preparation and their use as intermediate or ligand. The novel tertiary phosphines according to the present invent ion are compounds of the general formula EMI1.1 wherein R1 and R2 each, independently or taken together, represent an optionally substituted hydrocarbon group; R3 and R4 each independently represent a hydrogen atom, an optionally substituted hydrocarbon group, a group EMI1.2 or a group EMI1.3 wherein R8 and R9 each independently represent an optionally substituted hydrocarbon group; R5 and R6 each indeDendently represent a hydroxyl group, an optionally substituted hydrocarbon group, a group R10-O-, a group EMI1.4 or a group EMI1.5 wherein R10, Rill, R12 and R13 each independently represent an optionally substituted hydrocarbon group, or R5 and R6 taken together represent an oxygen atom or a group EMI2.1 wherein R14 represents an optionally substituted hydrocarbon group; and R7 represents a hydrogen atom or a group EMI2.2 The hydrocarbon groups may be alkyl-, alkylene-, aryl-, alkaryl-, arallyl groups having up to 20 carbon atoms. Preferred compounds according to the invention are those of the general formula I wherein R1 and R2 each represent an optionally substituted alkyl group having 1-8 carbon atoms or an optionally substituted phenyl group or R1 and R2 taken together represent an alkylene group having 4-12 carbon atoms: R3 and R4 each represent a hydrogen atom, an optionally substituted alkyl group having 1-8 carbon atoms or a group EMI2.3 wherein R9 represents an alkyl group having 1-6 carbon atoms and B5 and R6 represent a hydroxyl group, an optionally substituted alkyl group having 1-8 carbon atoms, an optionally substituted phenyl group or a group R10-O- wherein R10 represents an alkyl group having 1-6 carbon atoms or R5 and R6 taken together represent an oxygen atom or a group EMI2.4 wherein R14 represents an alkyl group having 1-6 carbon atoms. Most preferred compounds according to the present invention are those of the general formula I wherein B1 and R2 each represent an optionally substituted alkyl group having 1-8 carbon atoms or an optionally substituted phenyl group; R3 and R4 each represent a hydrogen atom and R5 and R6 taken together represent an oxygen atom. The present invention further relates to a process for the preparation of the compounds of the general formula I in which a secundary phosphine of the general formula EMI2.5 is reacted with a compound of the general formula EMI2.6 wherein R1 to R6 have the respective meanings as defined hereinbefore or R4 in addition represents Br, C1, a group EMI3.1 or a group R16-S03- wherein R15 and R16 each independently represent an optionally substituted hydrocarbon group, or the group EMI3.2 The secondary phosphines to be used in the process according to the invention are preferably phosphines of the general formula II wherein R1 and R2 represent an optionally substituted alkyl group having 1-8 carbon atoms or an optionally substituted phenyl group or R1 and R2 taken together represent an alkylene group having 4-12 carbon atoms. Typical examples of secondary phosphines are diphenylphosphine, di(2-methoxyphenyl)phosphine, di(4-trifluoromethylphenyl)phosphine, di(2-methylphenyl)phosphine, di(3-methylphenyl)phosphine, phenylbenzylphosphine, di(2-cyanoethyl)phosphine, phospholane or 9-phosphabicyclo[3.3.1]nonane. The use of optionally substituted diphenylphosphines is most preferred. When compounds of the general formula III, wherein R4 represents a hydrogen atom, an optionally substituted hydrocarbon group, a group EMI3.3 or a group EMI3.4 as defined hereinbefore are used the process of the invention yields mono tertiary phosphines of the general formula I wherein R7 represents a hydrogen atom. Using compounds of the general formula III wherein R4 represents Br, C1, a group EMI3.5 a group R16-SO3 as defined hereinbefore, bis tertiary phosphine compounds of the general formula I wherein R7 represents the group EMI3.6 are obtained. In particular compounds of the general formula III are used wherein R3 and R4 each independently represent a hydrogen atom, an optionally substituted alkyl group having 1-8 carbon atoms or a group EMI3.7 wherein R9 represents an alkyl group having 1-6 car bon atoms or R4 in addition represents Br, Cl, a group EMI4.1 or a group R16-S03- wherein R15 and R16 each independently represent an optionally substituted alkyl group or phenyl group and R5 and R6 each independently represent a hydroxyl group, an optionally substituted alkyl group having 1-8 carbon atoms or an optionally substituted phenyl group or a group R10-O- wherein R10 represents an alkyl group having 1-6 carbon atoms or R5 and R6 taken together represent an oxygen atom or a group EMI4.2 wherein R14 represents an alkyl group having 1-6 carbon atoms. Preferably, compounds of the general formula III are used wherein R3 represents a hydrogen atom, R4 represents a hydrogen atom, Br, C1 or a group EMI4.3 and R5 and R6 taken together represent an oxygen atom. The process of the invention is generally carried out using a non-oxidizing solvent. Suitable solvents may be for example halogen substituted hydrocarbons such as methylene chloride, chloroform, bromobenzene or perfluoroalkanes, hydrocarbons such as benzene, toluene, hexane or octane, ethers such as tetrahydrofuran, diethylether, dimethylether of diethylene glycol (diglyme), or 1,4-dioxane, amides such as N,N'-dimethylformamide, N,N'-dimethylacetamide or N-methylpyrrolidone, pyridine, nitriles such as acetonitrile or butyronitrile, esters such as methylacetate or ethylacetate or ketones such as acetone, methylethylketone or methyl-isobutylketone. The use of ethers in particular tetrahydrofuran or halogen substituted hydrocarbons in particular chloroform or methylenechloride as solvent is preferred. The reaction temperature in the process of the invention may vary from ambient temperature to temperatures up to 1500C. The compounds of the general formula I may be used as ligands or as intermediate for the preparation of ligands for trans it ion metal catalyzed reactions. It is to be noted that the compounds of the general formula I may comprise chiral carbon atoms. Compounds of the general formula I used as intermediates in the preparation of ligands are especially those compounds of the general formula I wherein R5 and R6 taken together represent oxygen. These compounds comprise mono-phosphines or bis-phosphines in which the phosphine groups are bound to the succinic acid anhydride skeleton, which is very suitable for further reactions with a nucleophile reagent, such as water, an alcohol or an amine. For example 2-phosphinopropionic acid, which can be used as ligands in Ni-catalyzed polymerization of ethylene (cf.: UK 1,305,122), can be prepared from.2-phosphinobutanedioic acid anhydride by reacting the anhydride with water and decarboxylating the 2-phosphinobutanedioic acid. The carboxylic acid group having a phosphino group in the alpha position appears to decarboxylate very smoothly giving the phosphinopropionic acid in high yield. 1,2-Bisphosphinoethane ligands may be prepared by hydrolysis of 2,3-bisphosphinobutanedioic acid anhydride followed by decarboxylation. In the following examples the identities of the novel compounds has been proven by means of 31p, 1H and 13C NMR analysis and elemental analysis. Example 1 Preparation of 2-diphenylphosphinobutanedioic acid from maleic anhydride. A solution of 9.8 g (100 mmol) maleic anhydride in 150 ml tetrahydrofuran is added in ca. 1 hour to a stirred solution of 26:1 ml (150 mmol) diphenylphosphine in 50 ml tetrahydrofuran. The orange solution is left overnight and subsequently 50 ml water is added, the solution is stirred for 1 hour and the tetrahydrofuran is removed in vacuum. To the residue is added a solution of 12 g NaOH in 250 ml water The resulting mixture is extracted with 200 ml ethylacetate. The aqueous layer is filtered and acidified with 30 ml concentrated hydrochloric acid. The resulting mixture was left overnight, upon standing pink crystals were formed in the oil phase of the mixture. The crystals were collected by filtration, washed with water and dried in vacuum. Yield 21.3 g 2-diphenylphosphinobutanedioic acid (70% of theory). 2-Diphenylphosphinopropionic acid can be prepared from 2-diphenylphosphinobutanedioic acid according to the following: A mixture of 20.7 g (68.5 mmol) diphenylphosphinosuccinic acid and 10 ml of toluene is heated at 1300C for three hours. The initial solid mass gradually changes to an oil. The mixture is allowed to cool and 100 ml of a 5% NaOH solution is added to dissolve the product The aqueous layer is extracted with ethyl acetate and subsequently acidified with 10 ml of concentrated hydrochloric acid. An oil is obtained that crystallises on standing overnight. The crystals are collected by filtration, thoroughly washed with water and then dried in vacuum. Yield 15.8 g (61.2 mmol) diphenylphosphinopropionic acid (89.3% of theory). Example 2 Preparation of 2-diphenylphosphinobutanedioic acid anhydride. A solution of 9.8 g (100 mmol) maleic anhydride in 150 ml tetrahydrofuran is added in ca. 1 hour to a stirred solution of 17.4 ml (100 mmol) diphenylphosphine in 50 ml tetrahydrofuran. The orange solution is left overnight and subsequently the solvent is evaporated leaving diphenylphosphinosuccinic anhydride according to NMR analysis. Example 3 Preparation of 1,2-dibenzoyl-1-diphenylphosphinoethane from trans1,2-dibenzoylethene. To a solution of 2.3 g (9.6 mmol) trans-1,2-dibenzoylethene in 25 ml tetrahydrofuran is added 1.7 ml (10 mmol) diphenylphosphine and the mixture is left overnight. After removing the tetrahydrofuran in vacuum, ether is added to induce crystallization. The crystals are collected by filtration, washed with cyclohexane and dried in vacuum. Yield 3.7 g (90% of theory). Example 4 Preparation of 2-diphenylphosphinobutanedioic acid from dimethylmaleate. A mixture of 16 g (111 mmol) dimethylmaleate 15 ml (86 mmol) diphenylphosphine and 50 ml chlorobenzene is heated at 1300C for ca. 70 hours. Subsequently, the solvent is removed in vacuum and the residue is mixed with 150 ml ethanol, 100 ml water and 17 g sodium hydroxide. The resulting mixture is refluxed for 3 hours. Then ethanol is removed by evaporation and the resulting residue is extracted with ethylacetate. On acidifying the aqeous layer 21.1 g 2-diphenylphosphinobutanedioic acid is obtained in the form of white crystals (81% of theory). Example 5 Preparation of 2,3-bis-(diphenylphosphino)butanedioic acid anhydride from bromomaleicanhydride. To a solution of 7 g (40 mmol) bromomaleicanhydride in 100 ml dichloromethane is added at a temperature of O-C, 14.7 g (79 mmol) diphenylphosphine. The mixture is stirred for 4 hours at roomtemperature. White crystals separated which are isolated by filtration and washed with 2 x 25 ml dichloroethane. After drying overnight in highvacuum 12.0 g (19 mmol) 2,3-bis(diphenylphosphino)butanedioic acid anhydride in the form of the bis-HBr salt is obtained (48% of theory). Example 6 Preparation of 2,3-bis-(diphenylphosphino)butanedioic acid anhydride from bromomaleicanhydride. To a solution of 7.5 g (42 mmol) bromomaleicanhydride in 100 ml diethylether is added at a temperature of OOC, 15.8 g (84 mmol) diphenylphosphine. The mixture is stirred for one hour at roomtemperature and the.yellow brown solid is isolated and washed with 3 x 20 ml diethylether. After drying in high-vacuum for 12 hours 16.3 g (30 mmol) 2,3-bis-(diphenylphosphino)butanedioic acid anhydride in the form of the mono-HBr salt is obtained (71Z of theory). Example 7 Preparation of 2,3-bis-(diphenylphosphino)butanedioic acid monomethylester from bromomaleicanhydride. To a solution of 17.7 g (100 mmol) in 150 ml tetrahydrofuran is added at a temperature of 0 C, 37.2 g (200 mmol) diphenylphosphine. The red solution is stirred for 3 hours at roomtemperature and subsequently quenched in a solution of 5.8 g sodium in 200 ml methanol at a temperature of -800C. Then the mixture is stirred until roomtemperature is reached and left at that temperature for half an hour without stirring. Tetrahydrofuran and methanol are removed in vacuum and the remaining yellow solid is suspended in 200 ml water. The suspension is acidified to pH2 and extracted with 100 ml dichloromethane. The organic layer thus produced is washed with water to pH 5-6 and dried on magnesium sulfate. Filtration and evaporation of the dichloromethane gives a yellow oil which crystallizes by trituration with ether to yield 20.6 g (42 mmol) 2,3-bis-(diphenylphosphino)butanedioic acid monomethylester (42% of theory).

Claims: CLAIMS 1. Tertiary phosphines of the general formula EMI9.1 wherein R1 and R2 each, independently or taken together, represent an optionally substituted hydrocarbon group; R3 and R4 each independently represent a hydrogen atom, an optionally substituted hydrocarbon group, a group EMI9.2 or a group EMI9.3 wherein R8 and R9 each independently represent an optionally substituted hydrocarbon group; R5 and R6 each independently represent a hydroxyl group, an optionally substituted hydrocarbon group, a group R10-0-, a group EMI9.4 or a group EMI9.5 wherein R1O, Rill, R12 and R13 each independently represent an optionally substituted hydrocarbon group, or R5 and R6 taken together represent an oxygen atom or a group EMI9.6 wherein R14 represents an optionally substituted hydrocarbon group; and R7 represents a hydrogen atom or a group EMI9.7 2. Tertiary phosphines according to claim 1, wherein the hydrocarbon groups are alkyl-, alkylene-, aryl-, alkaryl- or aralkyl groups having up to 20 carbon atoms. 3. Tertiary phosphines according to claim 2, wherein R1 and R2 each represent an optionally substituted alkyl group having 1-8 carbon atoms or an optionally substituted phenyl group or R1 and R2 taken together represent an alkylene group having 4-12 carbon atoms; R3 and R4 each represent a hydrogen atom, an optionally substituted alkyl group having 1-8 carbon atoms or a group EMI10.1 wherein R9 represents an alkyl group having 1-6 carbon atoms and R5 and R6 represent a hydroxyl group, an optionally substituted alkyl group having 1-8 carbon atoms, an optionally substituted phenyl group or a group R10-0- wherein R10 represents an alkyl group having 1-6 carbon atoms or R5 and R6 taken together represent an oxygen atom or a group EMI10.2 wherein R14 represents an alkyl group having 1-6 carbon atoms. 4. Tertiary phosphines according to claim 3, wherein R1 and R2 each represent an optionally substituted alkyl group having 1-8 carbon atoms or an optionally substituted phenyl group; R3 and R4 each represent a hydrogen atom and R5 and R6 taken together represent an oxygen atom. 5. Tertiary phosphines according to claim 1 specifically mentioned in any one of the examples 1-7. 6. A process for the preparation of tertiary phosphines as claimed in any one of the preceding claims, characterized in that a secundary phosphine of the general formula EMI10.3 reacted with a compound of the general formula EMI10.4 wherein R1 to R6 have the respective meaning as defined hereinbefore or R4 in addition represents Br, C1, a group EMI11.1 or a group R16-S03- wherein R15 and R16 each independently represent an optionally substituted hydrocarbon group, or the group EMI11.2 7. A process as claimed in claim 6, characterized in that R1 and R2 each represent an optionally substituted alkyl group having 1-8 carbon atoms or an optionally substituted phenyl group or R1 and R2 taken together represent an alkylene group having 4-12 carbon atoms. 8. A process as claimed in claim 6 or 7, characterized in that the secondary phosphine is an optionally substituted diphenylphosphine. 9. A process as claimed in any one of claims 6 to 8, characterized in that R3 represents a hydrogen atom, R4 represents a hydrogen atom, Br, C1, a group EMI11.3 and R5 and R6 taken together represent an oxygen atom. 10. A process as claimed in any one of claims 6 to 9, characterized in that it is carried out using an ether or halogenated hydrocarbon as solvent. 11. A compound according to the general formula I, whenever prepated according to the process as claimed in any one of claims 6 to 10. 12. A compound according to claim 1, whenever used as ligand. 13. A compound according to claim 1, whenever used as intermediate in the preparation of ligands. 14. A compound according to claim 1, wherein R5 and R6 taken together represent an oxygen atom, whenever used as intermediate in the preparation of ligand by reacting with a nucleophile reagent.

Inventors: MEIJBOOM, NICOLAAS, VAN DOORN, JOHANNES ADRIANUS, WIFE, RICHARD LEWIN
Applicants: SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ B.V.
Application year: 1985
Main classification: C07F9
IPC codes: C07F9