Dendritic macromolecules for metal-ligand catalyzed processes

Details Dendritic macromolecules for metal-ligand catalyzed processes Dendritic macromolecules for metal-ligand catalyzed processes

2000-10-27

2002-02-26

Seidleck, James J. (Department: 1711)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Mixing of two or more solid polymers; mixing of solid...

C528S167000, C568S454000

Reexamination Certificate

active

06350819

ABSTRACT:

BRIEF SUMMARY OF THE INVENTION
1. Technical Field
This invention relates to dendritic macromolecules and their use in metal-ligand complex catalyzed processes. More particularly this invention relates to metal-dendritic macroligand complex catalyzed processes in which separation of the desired product from the catalyst is facilitated.
2. Background of the Invention
A number of industrially important processes such as hydrogenation, carbonylation, and hydroformylation involve homogeneous catalysts containing complexes of transition metals with organic ligands. In particular, hydroformylation of olefins to produce aldehydes occurs in the presence of syngas (carbon monoxide and hydrogen) and transition metal complexes with various organophosphorus ligands.
Many transition metal complexes catalyze the hydroformylation reaction, but cobalt and rhodium are especially important industrially. Rhodium catalysts have gained increasing significance over the cobalt ones in hydroformylation due to possibility of low pressure conditions. Employed ligands include predominantly phosphines and phosphites. Phosphite ligands are often preferable due to enhanced hydroformylation activity and excellent selectivity to the desired product. The selectivity involves high regioselectivity (predominant formation of normal versus branched product) and high stereoselectivity (preferential generation of the desired enantiomer or diastereomer). Phosphite ligands can also be tailored to maintain sufficient catalyst stability for industrial applications.
Separation of products from catalysts involving low molecular weight aldehydes is usually performed by the simple physical processes of vaporization or distillation. Difficulties in the recovery and reuse of hydroformylation catalysts and ligands are a concern in commercial processes. It is also commonly recognized that stripping of higher molecular weight products such as C6-C20 aldehydes and especially thermally sensitive carbonyl compounds such as dialdehydes and monoaldehydes with various functional groups using the same separation methods are often problematic. Indeed, heating the corresponding reaction product mixtures may result in the excessive loss of the organophosphorus ligands or irreversible transformations of the target aldehydes. Overcoming these limitations is particularly important for rhodium-based catalysts and organophosphite ligands due to their high cost. Several alternative product removal techniques have been attempted to streamline separation of rhodium catalysts from high boiling aldehyde products. See. for example, U.S. Pat. Nos. 5,138,101, 4,879,418, 5,180,854, 5,463,082, 5,952,530, 5,932,772, 5,395,979, 5,681,473, and 5,773,667.
Attempts also have been made to facilitate separation of catalysts from products in homogeneous catalysis using polysilane dendrimers functionalized with nickel-containing catalytically active sites (Knapen et al.
Nature
1994, 372, 659-663). These catalysts are shown to be active for the Kharasch addition of polyhalogenoalkanes to carbon-carbon double bonds. Removal of their complexes from the solution of products are thought to be achievable by ultrafiltration methods but have not been demonstrated experimentally. This article does not disclose dendritic organophosphorus ligands and rhodium catalysts.
Dendrimeric organophosphorus ligands containing phosphine sites capable of complexing to palladium, platinum, and rhodium are known, e.g. Bardaji et al
Organometallics
1997, 16, 403-410. Applications of dendritic ligands in hydroformylation is documented for phosphine-coated dendrimers (Reetz et al.
Angew. Chem. Int. Ed. Engl
. 1997, 36, 1526-1529). These dendrimers are functionalized with phosphine groups only.
A more efficient and cost effective method for separating catalyst from product in homogeneous catalyzed processes would be highly desirable in the art.
DISCLOSURE OF THE INVENTION
It has now been discovered that in metal-organophosphorus ligand complex catalyzed processes, the desired product can be effectively separated from the catalyst. By the practice of this invention, it is now possible to separate the desired product from the catalyst without the need to use vaporization separation and the harsh conditions associated therewith. This invention facilitates a highly desirable separation which prevents and/or lessens degradation of the organophosphorus ligand and deactivation of the catalyst as occur under harsh conditions with vaporization separation.
It has been discovered that organophosphorus-containing dendritic macromolecules of this invention may be employed as soluble macroligands with nanoscale dimensions and spherical or near-spherical shape, in transition metal complex catalyzed homogeneous processes, such as hydroformylation processes, to provide active, stable and separable transition metal-dendritic macroligand complex catalysts. For example, the organophosphorus-containing dendritic macroligands of this invention are useful in providing unique separation capabilities of products from catalysts while retaining desirable catalytic activity, selectivity and stability. The organophosphorus-containing dendritic macroligands of this invention are especially useful in the processes involving higher molecular weight olefins or thermally sensitive oxo products when separations by vaporization or other known means are limited or impossible.
This invention relates in part to dendritic macromolecules having a core and one or more branches emanating from the core wherein at least a portion of the branches contain terminal groups derived from organophosphites, organophosphonites and/or organophosphinites.
This invention also relates in part to dendritic macromolecules having a core and one or more branches emanating from the core wherein at least a portion of the branches contain terminal groups derived from a trivalent phosphorus-containing group of the formula
This invention further relates in part to dendritic macromolecules represented by the formula:
wherein A represents a q-valent dendritic macromolecule radical, each B is the same or different and represents a substituted or unsubstituted r-valent organic or inorganic radical, each Y is the same or different and represents a substituted or unsubstituted monovalent hydrocarbon radical containing from 6 to 40 carbon atoms or each adjacent Y may be bridged together to form a substituted or unsubstituted cyclic hydrocarbon radical, m is a value of from 1 to about 3, n is a value of from 1 to about 1000, q equals n, and r equals m+1.
This invention yet further relates in part to a metal-dendritic macroligand complex catalyst comprising a Group 8, 9 or 10 metal complexed with a dendritic macroligand represented by the formula:
wherein A represents a q-valent dendritic macromolecule radical, each B is the same or different and represents a substituted or unsubstituted r-valent organic or inorganic radical, each Y is the same or different and represents a substituted or unsubstituted monovalent hydrocarbon radical containing from 6 to 40 carbon atoms or each adjacent Y may be bridged together to form a substituted or unsubstituted cyclic hydrocarbon radical, m is a value of from 1 to about 3, n is a value of from 1 to about 1000, q equals n, and r equals m+1.
This invention also relates in part to a process for producing one or more products comprising reacting one or more reactants in the presence of a metal-dendritic macroligand complex catalyst to produce said one or more products, in which said metal-dendritic macroligand complex catalyst comprises a Group 8, 9 or 10 metal complexed with a dendritic macroligand represented by the formula:
wherein A represents a q-valent dendritic macromolecule radical, each B is the same or different and represents a substituted or unsubstituted r-valent organic or inorganic radical, each Y is the same or different and represents a substituted or unsubstituted monovalent hydrocarbon radical containing from 6 to 40 carbon atoms or each adjacent Y may be bridged together to form a substitute

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