Title of Invention

"A PROCESS FOR THE PREPARATION OF NEW TRANSITION METAL COMPLEXES"

Abstract

A process for the preparation of new transition metal complexes by reacting a metal source with a semilabile anionic chelating ligand which contains a N donor and an O" group, a monodentate phosphorus ligand and a protonic acid in an organic solvent, under constant stirring at temperature in the range of 25 to 30°C for a period ranging from 1 to 15 minutes precipitating the product using an organic solvent, washing and drying the precipitate to obtain the product.

Full Text

This invention relates to a process for the preparation of new transition metal complexes. The complexes prepared by the process of the present invention may particularly be useful as efficient catalysts for carbonylation of olefins, diens, alkynes, nitrocompounds and alcohols and co-polymerization of olefins with carbonmonoxide More particulary it relates to the prepreparation of series of new group VIII metal complexes having general formula 1 in the drawing ccompanying this specification wherein, M represents the central transition metal, N O represents a semilabile anionic chelating ligand, R1, R2 and R3 are the substituents of phosphine ligand, and X is a sulphonato, carboxylalo or formalo group, or any of the halitles. Group VIII metal complexes containing bidentate ligands have been shown to be very effective catalysts for a variety of carbonylation and co-polymerization reactions. While a variety of complexes containing bidentate ligands are useful for such chemical conversions, synthesis of stable metal complexes having high catalytic activity for a wide range of such reactions is often difficult. Although many group VIII metal complexes involving bidentate ligands have been reported in the literature, the complex having the formula 1 has been synthesized for the first time and there is no prior art available for synthesising these complexes. The main object of the present invention is to provide a process for the preparation of a new class of group VIII metal complexes that may be useful catalysts for carbonylation and copolymerization of a wide variety of organic compounds. Accordingly the present invention provides a process for the preparation of group VIII metal complexes having general formula 1, wherein M = a group VIII metal, R1 R2, R3 — substituents on phosphine ligands, such as hydrogen, alkyl, arylalkyl, cycloalyphatic, X= aryl or alkyl sulphonato or aryl or alkyl carboxylato or formato or halides such as CI", Br", I", l In one of the embodiments, the preparation of group VIII metal complexes having general formula 1 where X=halides may also be carried out by mixing any of the corresponding halide salts with a solution of compound having formula I wherein X is a aryl or alkyl sulphonato or aryl or alkyl carboxylato or formato group, in an organic solvent, under constant stirring at ambient temperature for a period ranging from 1 to 15 minutes, filtering, washing and drying the precipitate to obtain the product. In another embodiment the semilabile anionic chelating ligand in the compound having formula I may be an organic compound, containing a N donor and an O" group, exemplified by 8-hydroxy quinoline, 2-hydroxy pyridine, 2-(2-hydioxy cthyl)pyridinc, pyridyl-2-, pipcridyl-2-, quinolyl- 2-, isoquinolyl-1- and isoquinolyl-3- carboxylates, particulaly pyridyl-2-carboxylate, piperidyl-2 carboxylatc, and 8-hydroxyquinoline. In another embodiment the group VIII metal source used preferably may be palladium or platinum compounds such as palladium or platinum acetate, palladium dibenzylidine acetone, palladium acetylacetonate, and tetrakis triphenyl phosphino palladium. In still another embodiment phosphorous ligand used may be any of the mono phosphines, preferably phosphines such as triphenyl phosphine, tris paratolyl phosphine , tris para chlorophenyl phosphine, tris para methoxyphenyl phosphine, tricyclohexyl phosphine, tributyl phosphine and methyl diphenyl phosphine. In another embodiment the protonic acid used may be selected from, para toluene sulphonic acid, methane sulphonic acid, triflouro methane sulphonic acid, acetic acid, formic acid, oxalic acid and trifouro acetic acid. In yet another embodiment the halide salts used may be such as lithium chloride, lithium bromide, lithium iodide, sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, potassium iodide. In still another embodiment the solvent used may be such as chloroform , dichloromethane, aromatic hydrocarbons like, benzene, toluene, xylenes, ketones like methyl ethyl ketone, acetone, amides like N-methyl pyrrolidone, or alcohols like methanol, ethanol. In another embodiment the number of moles of the anionic semilabile ligand per gram atom of metal, may be 1 to 10 preferably 1-2. In still another embodiment the number of moles of protonic acid per gram atom of metal , may be 1 to 10 preferably 2 to 3. In yet another embodiment the ratio of number of moles of the mono phosphine ligand per gram of metal, may be 1 to 10 preferably 2 to 3. The process of the present invention is described herein below with reference to examples, which are illustrative only and should not be construed to limit the scope of the present invention in any manner. EXAMPLE 1 Pd(OAc)2: 0.89mmol, 2-picolinic acid: 0.89mmol, triphenyl phosphine :1.8mmol and para toluene sulphonic acid: 1.8mmol were dissolved in chloroform at room temperature and shaken vigorously for 2 minutes, by instantaneous formation the product as a deep yellow solution. The product was then precipitated out as an yellow oil using diethyl ether, which was washed several times with diethyl ether and n-hexane. This oil on vacuum drying gave stable yellow porous crystals with yield = 99% EXAMPLE 2 Pt(OAc)2 : 0.89mmol, 2-picolinic acid: 0.89mmol, triphenyl phosophine: 1.8 mmol and para toluene sulphonic acid: 1.8mmol were dissolved in chloroform at room temperature and shaken vigorously for 2 minutes, by instantaneous formation the product as a deep yellow solution. The product was then precipitated out as an yellow oil using diethyl ether, which was washed several times with diethyl ether and n-hexane. This oil on vacuum drying gave stable yellow porous crystals with yield = 99% EXAMPLE 3 Pd(OAc)2: 0.89mniol, 2-pipecolinic acid: 0.89mmol, triphenyl phosphine : 1.8 mmol and para toluene sulphonic acid: l.8mmol were dissolved in chloroform at room temperature and stirred well for 5minutes, immediately forming a deep yellow solution. The product was then precipitated out as an yellow oil using diethyl ether, which was washed several times with diethyl ether and n-hexane. This oily product on vacuum drying gave stable yellow porous crystals with yield - 98% EXAMPLE 4 Pd(OAc)2: 0.89mmol, 8-hydroxy quinoline: 0.89mmol, triphenyl phosphine : 1.8 mmol and para toluene sulphonic acid: 1.8mmol were dissolved in chloroform at room temperature and stirred well for 5minutes, immediately forming a deep yellow solution. The product was then precipitated out as an yellow oil using diethyl ether, which was washed several times with diethyl ether and n-hexane. This oily product on vacuum drying gave stable yellow porous crystals with yield = 98% EXAMPLE 5 Pd(OAc)2: 0.89mmol, 2-picolinic acid: 0.89mmol, tris para chloro phenyl phosphine : l.Snimol and para toluene sulphonic acid: 1.8mmol were dissolved in chloroform at room temperature and stirred well for 15 min, resulting in a deep yellow solution. The product was then precipitated out as an yellow solid, using diethyl ether, which was washed several times with diethyl ether and n-hexanc and vacuum dried. Yield was 98%. EXAMPLE 6 Pd(OAc)2: 0.89mmol, 2-picolinic acid: 0.89mmol, tris para tolyl phosphine : l.8mmol and para toluene sulphonic acid:1.8mmol were dissolved in chloroform at room temperature and stirred well for 5 min, resulting in a deep yellow solution. The product was then precipitated out as an yellow oil using diethyl ether, which was washed several times with diethyl ether and n-hexane. This oil on vacuum drying gave stable yellow porous crystals with 98% yield. EXAMPLE 7 Pd(OAc)2: 0.89mmol, 2-picolinic acid: 0.89mmol, triphenyl phosphine :1.8mmol and methane sulphonic acid: 1.8nimol were dissolved in chloroform at room temperature and shaken thoroughly for 2 minutes, immediately forming a deep yellow solution. The product was then precipitated out as an yellow oil using diethyl ether, which was washed several times with diethyl ether and n-hexane. This oil on vacuum drying gave stable yellow porous crystals with 98% yield. EXAMPLE 8 Pd(OAc)2: 0.89mmol, 2-picolinic acid: 0.89mmol, tricyclohexyl phosphine :1.8mmol and para toluene sulphonic acid: 1.8mmol were dissolved in chloroform at room temperature and stirred well for 15 min, resulting in a deep yellow solution. The product was then precipitated out as an yellow oil using diethyl ether, which was washed several times with diethyl ether and n-hexane. This oil on vacuum drying gave stable yellow porous crystals with 95% yield. EXAMPLE 9 Pd(OAc)2: 0.89mmol, 2-picolinic acid: 0.89mmol, triphenyl phosphine :1.8mmol and formic acid: l.8mmol were dissolved in chloroform at room temperature and stirred well for 15 min, resulting in a deep yellow solution. The product was then precipitated out as an yellow oil using diethyl ether, which was washed several times with diethyl ether and n-hexane. This oil on vacuum drying gave stable yellow porous crystals with yield = 95%. EXAMPLE 10 The complex obtained from example 1: 0.89 mmol, lithium chloride: 0.89 mmol were dissolved in chloroform at room temperature and stirred well for 15 min, forming a pale yellow precipitate. This precipitate was filtered, washed several times with diethyl ether and n-hexane and dried under vacuum. Yield = 93%. Advantages of present invention 1. Invention of new transition metal complexes which are stable and may be useful catalysts for a variety of carbonylation and co-polymerization reactions 2. An easy single step process for the synthesis of a series of transition metal complexes with high yield. We claim: 1. A process for the preparation of group VIII metal complexes having general formula 1, wherein M = a group VIII metal, R1, R2, R3 = substituents on phosphine ligands, such as hydrogen, alkyl, arylalkyl, cycloalyphatic, X= aryl or alkyl sulphonato or aryl or alkyl carboxylato or formato groups or halides such as CI", Br", I", l 2. A process as claimed in claim 1 wherein the preparation of group VIII metal complexes having general formula 1 where X=halides is also carried out by mixing any of the corresponding halide salts with a solution of compound having formula I wherein X is a aryl or alkyl sulphonato or aryl or alkyl carboxylato or formato group, in an organic solvent, under constant stirring at ambient temperature for a period ranging from 1 to 15 minutes, filtering, washing and drying the precipitate to obtain the product. 3. A process as claimed in claims 1 and 2 wherein the semilabile anionic chelating ligand in the compound having formula I is an organic compound, containing a N donor and an O" group, exemplified by 8-hydroxy quinoline, 2-hydroxy pyridine, 2-(2-hydroxy ethyl)pyridine, pyridyl-2-, piperidyl-2-, quinolyl- 2-, isoquinolyl-1 - and isoquinolyl-3-carboxylate, particulaly pyridyl-2-carboxylate, piperidyl-2 carboxylate, and 8-hydroxyquinoline 4. A process as claimed in claims 1 to 3 wherein the group VIII metal source used preferably is palladium or platinum compounds selected from palladium or platinum acetate, palladium dibenzylidine acetone, palladium acetylacetonate, and tetrakis triphenyl phosphino palladium . 5. A process as claimed in claims 1 to 4 wherein the phosphorous ligand used is any of the mono phosphines, preferably phosphines selected from triphenyl phosphine, tris paratolyl phosphine , tris para chlorophenyl phosphine, tris para methoxyphenyl phosphine, tricyclohexyl phosphine, tributyl phosphine and methyl diphenyl phosphine. 6. A process as claimed in claims 1 to 5 wherein the protonic acid used is selected from, para toluene sulphonic acid, methane sulphonic acid, triflouro methane sulphonic acid, acetic acid, formic acid, oxalic acid and trifouro acetic acid. 7. A process as claimed in claims 1 to 6 wherein the halide salts used is selected from lithium chloride, lithium bromide, lithium iodide, sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, and potassium iodide. 8. A process as claimed in claims 1 to 7 wherein the solvent used is selected from chloroform, dichloromethane, aromatic hydrocarbons selected from benzene, toluene, xylenes, ketones like methyl ethyl ketone, acetone, amides like N-methyl pyrrolidone, or alcohols like methanol, ethanol. 9. A process as claimed in claims 1 to 8 wherein the number of moles of the anionic semilabile ligand per gram atom of metal, is 1 to 10 preferably 1 to 2. 10. A process as claimed in claims 1 to 9 wherein the number of moles of protonic acid per gram atom of metal, is 1 to 10 preferably 2 to 3. 11. A process as claimed in claims 1 to 10 wherein the ratio of number of moles of the mono phosphine ligand per gram of metal, is 1 to 10 preferably 2 to 3. 12. A process for preparation of new transition metal complexes as herein described with reference to the examples and the drawing accompanying the specification.

Documents:

3698-del-1998-abstract.pdf

3698-del-1998-claims.pdf

3698-del-1998-complete specification (granted).pdf

3698-del-1998-correspondence-others.pdf

3698-del-1998-correspondence-po.pdf

3698-del-1998-description (complete).pdf

3698-del-1998-drawings.pdf

3698-del-1998-form-1.pdf

3698-del-1998-form-19.pdf

3698-del-1998-form-2.pdf

3698-del-1998-form-3.pdf