Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Organic compound containing
Reexamination Certificate
2000-08-25
2003-04-08
Bell, Mark L. (Department: 1755)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Organic compound containing
C502S152000
Reexamination Certificate
active
06544923
ABSTRACT:
FIELD OF INVENTION
The present invention relates to novel ultra-large porous compositions, and organometallic catalysts immobilized on these compositions, including asymmetric organometallic catalysts. Reactions performed by these catalysts include hydrogenation, hydroformylation, carbonylation, carbon-carbon coupling reactions, as well as asymmetric reactions such as asymmetric hydrogenation.
BACKGROUND OF THE INVENTION
Many industrially important reactions, especially in the fine chemicals and pharmaceuticals industries, involve the use of expensive homogeneous catalysts. The homogeneous catalysts show good activity and can be tailored to allow for a high degree of product selectivity.
Such active and selective homogeneous catalysts are expensive to synthesize, and typically are very difficult to recover from reaction mixtures. The complexity of catalyst synthesis and separation procedures leads to high costs due to capital investment in high-temperature distillation and/or liquid-liquid separation equipment used in the separation of the catalyst from the reaction mixture, and due to operating costs incurred by rapid catalyst loss and deactivation. Overcoming or decreasing these obstacles is necessary to meet growing demand for highly specific molecular products, especially in life sciences industries. This demand has driven the commercial desirability of organometallic catalysts for reactions involving carbon-carbon bond formation (e.g., Heck and Suzuki coupling) and enantioselective hydrogenations.
Although heterogeneous catalysts do not afford comparable performance, these catalysts offer other advantages such as ease of catalyst recovery. In order to create an easily separable and reusable catalyst, a number of different techniques have been developed to “heterogenize” homogeneous transition metal catalysts for various catalytic reactions. These techniques involve (i) dissolution of modified homogeneous catalysts in a liquid phase which is not miscible with the reaction solvent, and subsequent support of the non-soluble phase on solid particles, or (ii) covalent linkage of catalyst molecules to silica beads and polymer matrices. These methods, however, result in low surface area catalysts that have only a small fraction of active component exposed to the reaction mixture. These limitations can lead to long reaction times and large reactor volumes.
The synthesis of stereospecific products also presents a great need in the life sciences industry. There are extensive literature reports on the preparation of new asymmetric catalysts through immobilization of chiral metal complexes to solid supports. Immobilization typically involves a covalent linkage via functionalized chiral ligands. This method is successful to some extent as leaching of expensive chiral ligand can be minimized. However, this method does have its drawbacks. The majority of chiral ligands does not contain functional groups that allow direct linkage to solid supports such as silica gels. Modifying the chiral ligand with a functional group is often expensive, involving lengthy synthetic steps, and is detrimental to the selectivity of the catalyst. Furthermore, the sensitivity of the functional groups (i.e. trialkoxysilyl group) towards water tends to complicate synthesis.
Thus, it remains a challenge to prepare catalysts that exhibit high activity and selectivity through immobilization of the catalysts to a surface capable of being easily recovered from solution. It also remains a challenge to prepare asymmetric catalysts having high enantioselectivity. In addition, the immobilized catalysts should ideally be stable to a wide variety of catalytic conditions.
SUMMARY OF THE INVENTION
One aspect of the present invention provides an article comprising an organometallic catalyst immobilized on a polymer-templated composition having at least about 50% of a total pore volume comprising pores with a mean diameter of at least about 50 Å.
Another aspect of the present invention provides an article comprising an asymmetric organometallic catalysts immobilized on a surface via an achiral ligand.
Another aspect of the present invention provides a method for making a catalysts. A method comprises forming a mesoporous composition via a polymer template, the mesoporous composition having at least about 50% of a total pore volume comprising pores with a mean diameter of at least about 50 Å. The method also comprises immobilizing an organometallic catalysts on the mesoporous composition.
Another aspect of the present invention provides a method for performing a catalytic reaction. The method comprises contacting a catalyst with a substrate. The catalyst comprises an organometallic complex immobilized on a mesoporous composition having at least about 50% of a total pore volume comprising pores with a mean diameter of at least about 50 Å.
Another aspect of the present invention provides an article comprising a polymerization catalyst immobilized on a porous composition. The composition has pores of a predetermined mean diameter to define a molecular weight distribution of a polymer.
Another aspect of the present invention provides an article comprising catalyst immobilized on a porous composition. The composition has pores of a predetermined mean diameter to influence stereoselectivity.
Another aspect of the present invention provides a system comprising a plurality of supports. Each support comprises a composition having pores of a mean diameter of at least about 50 Å.
Other advantages, novel features, and objects of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings, which are schematic and which are not intended to be drawn to scale. In the figures, each identical or nearly identical component that is illustrated in various figures is represented by a single numeral. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the invention shown where illustration is not necessary to allow those of ordinary skill in the art to understand the invention.
REFERENCES:
patent: 4937218 (1990-06-01), Ramirez De Aqudelo et al.
patent: 5139985 (1992-08-01), Barbe et al.
patent: 5145816 (1992-09-01), Beck et al.
patent: 5200058 (1993-04-01), Beck et al.
patent: 5244857 (1993-09-01), Pugin et al.
patent: 5252751 (1993-10-01), Pugin et al.
patent: 5645891 (1997-07-01), Liu et al.
patent: 5712402 (1998-01-01), Pinnavaia et al.
patent: 5736480 (1998-04-01), Davis et al.
patent: 5795559 (1998-08-01), Pinnavaia et al.
patent: 5800799 (1998-09-01), Pinnavaia et al.
patent: 5824622 (1998-10-01), Harmer et al.
patent: 5932511 (1999-08-01), Harmer et al.
patent: 5935897 (1999-08-01), Trubenbach et al.
patent: 5935898 (1999-08-01), Trubenbach et al.
patent: 5951962 (1999-09-01), Müller et al.
patent: 5990318 (1999-11-01), Chan et al.
patent: 5997840 (1999-12-01), Van Brussel et al.
patent: 6028025 (2000-02-01), Ying et al.
patent: 0 831 059 (1998-03-01), None
patent: 0 865 823 (1998-09-01), None
patent: WO 98/17389 (1998-04-01), None
patent: 98/17389 (1998-04-01), None
patent: WO 98/46353 (1998-10-01), None
R. Noyori and T. Ohkuma, “Asymmetric Catalysis by Architectural and Functional Molecular Engineering: Practical Chemo—and Stereoselective Hydrogenation of Ketones,”Angew. Chem. Int. Ed, 2001, vol. 40, pp. 40-73.
Ekkehard Lindner et al., “Chemistry in Interphases—A New Approach to Organometallic Syntheses and Catalysis” Angew. Chem. Int. Ed. 1999, 38, 2154-2174.
C.T. Kresge et al., “Ordered mesophorous molecular sieves synthesized by a liquid-crystal template mechanism” Nature, vol. 359, Oct. 22, 1992, pp. 710-712.
B. Pugin and M. Muller, “Enantioselective Metal Complex Catalysis Immobilized on Inorganic Supports Via Carbamate Links” Heterogeneous Catalysts and Fine Chemicals III, 1993 Elsevier Science Publishers, pp. 107-114.
D. Zhao et al., “Triblock Copolymer Syntheses of Mesoporous Silica with Periodic 50 to 300 Angstrom Pores” Science, vol. 279, Ja
Huang Dejian
Lettow John S.
Mehnert Christian P.
Ying Jackie Y.
Bell Mark L.
Massachusetts Institute of Technology
Pasterczyk J.
Wolf Greenfield & Sacks P.C.
LandOfFree
Surface-confined catalytic compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Surface-confined catalytic compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Surface-confined catalytic compositions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3107749