Access to silica- and monolithic polymer supported CC-coupling catalysts via ROMP: applications in high-throughput screening, reactor technology and biphasic catalysis

Buchmeiser, Michael R.; Lubbad, Said H.; Mayr, Monika; Wurst, Klaus

doi:10.1016/s0020-1693(02)01291-4

Cited by 63 publications

(32 citation statements)

References 47 publications

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“…Thus, the heterogeneous Heck reaction in water was investigated as shown in Table 14. [123][124][125][126] We were fueled by finding that PdAS-V has a good stability and activity even in water. The coupling of 19a with acrylic acid (32) proceeded smoothly in 6 h to result in the formation of cinnamic acid (33a) in 95% yield (entry 1).…”

Section: The Heck Reaction Of Aryl Iodides With Styrenes In Toluenementioning

confidence: 99%

Self-Assembled Complexes of Non-cross-linked Amphiphilic Polymeric Ligands with Inorganic Species: Highly Active and Reusable Solid-Phase Polymeric Catalysts

Yamada

2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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IntroductionDevelopment of immobilized and insoluble metal catalysts is of great interest in recent organic chemistry. [1][2][3][4][5][6][7][8][9] The simple recovery of catalysts by filtration and their reuses resulted in enhancing the economical evaluation of the reaction. At the same time, there is a prospect that the environmental pollution caused by residual metals in the waste fluid will be decreased. Although a great deal of effort has been made to carry out such ideal reactions using immobilized metal catalysts, what seems to be lacking is the efficiency of the catalytic systems. It is obvious that the heterogeneous catalytic systems exhibit generally lower activity than the homogeneous ones. Besides, it is expected that the activity of the catalysts decreases gradually in the recycled systems because the metal species leaches away from their supports. Taking these into consideration, we decided to concentrate on developing insoluble metal catalysts which are highly active and stable. We designed that they were still effective in the use of ppm mol eq, and in the recycled use of many times in any reaction media. To achieve the challenging theme, we have focused on the amphiphilic insoluble catalysts based on a novel concept (Chart 1).Over the past few decades, a considerable numbers of study have been made on solid-phase catalysts which were immobilized with cross-linked polystyrene resins, silica gels or metals. These catalytic systems, however, generally resulted in lower catalytic activity compared with their soluble counterparts, and were often obliged to use hazardous chlorohydrocarbon solvents. [10][11][12][13][14][15] Besides, reuse of these catalysts was often difficult owing to the gradual decline of the catalytic activity. These problems made them less practical.In traditional triphase catalysts, as I have mentioned before, a catalytic species was anchored to a linker that was immobilized to a polymer resin or silica gel (Chart 1, above). In July 2005Chem. Pharm. Bull. 53(7) 723-739 (2005)

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Section: The Heck Reaction Of Aryl Iodides With Styrenes In Toluenementioning

confidence: 99%

Self-Assembled Complexes of Non-cross-linked Amphiphilic Polymeric Ligands with Inorganic Species: Highly Active and Reusable Solid-Phase Polymeric Catalysts

Yamada

2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…[2] Therefore, a presynthesized monomer complex was employed, N,N-dipyrid-2-yl-7-oxanorborn-2-en-5-ylcarbamido palladium dichloride, along with NBE to graft palladium catalysts onto the polymeric monoliths and to prevent coordination of the dipyridylamide ligands with the living ruthenium groups on the monolith. [2,132] Pd loadings up to 0.07 % were achieved, and turnover numbers of 1.2-1.6 s À1 resulted for styrene and iodobenzene model reactions. [2,132] This result is comparatively greater than that of polymer-supported catalysts from ROMP-based precipitation polymerization.…”

Section: Pd-based Catalysts For Càc Coupling Reactionsmentioning

confidence: 99%

“…[2,132] Pd loadings up to 0.07 % were achieved, and turnover numbers of 1.2-1.6 s À1 resulted for styrene and iodobenzene model reactions. [2,132] This result is comparatively greater than that of polymer-supported catalysts from ROMP-based precipitation polymerization. [2] Palladium leaching in the products was less than 2.2 %.…”

Section: Pd-based Catalysts For Càc Coupling Reactionsmentioning

confidence: 99%

“…Continuous flow reactions of styrene with iodobenzene in tributylamine showed production of stilbene over 3 h. However, turnover numbers were comparable to those of supports from ROMP-based precipitation polymerization. [132,133] Buchmeiser et al also introduced the formation of palladium nanoparticles in the pores of monolithic media for Heck, Suzuki, and Sonogashira-Hagihara-type cross-couplings, [11,41] which is discussed further below.…”

Section: Pd-based Catalysts For Càc Coupling Reactionsmentioning

confidence: 99%

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Catalysts Immobilized on Organic Polymeric Monolithic Supports: From Molecular Heterogeneous Catalysis to Biocatalysis

Anderson

Buchmeiser

2011

ChemCatChem

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This review describes the synthetic routes to various types of organic polymeric monoliths. Significant concentration is applied to the role of these continuous, porous structures in both heterogeneous catalysis and biocatalysis. A monolith is composed of a solitary mass filled with interconnected pores, which include both large flow‐through pores and smaller meso‐ or micropores. These porous monolithic materials have several advantages over conventional packed beds of porous polymeric beads, owing to their macroporosity and lack of interstitial spacing. Their large pores contribute to mass transfer, which allows the structure to withstand higher back pressures than conventional packed beds, whereas their small pores still operate by diffusion. The effect of multiple parameters, such as the temperature, the cross‐link density, and the type and content of porogenic solvent on the pore formation and pore size distribution is outlined for monoliths prepared through free radical polymerization and ring‐opening metathesis polymerization (ROMP). Post‐functionalization of these monoliths to control the surface chemistry of the supports and/or affix functional catalysts is elucidated, as well as employment of these supports in continuous catalytic reactions. Significant advances in supported catalysis for metathesis, Heck, Suzuki, Sonogashira–Hagihara, and biocatalytic reactions are described.

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“…This corresponds to an immobilization ratio of 0.1 mmol of 4 per g of SiO 2 and accordingly 5 wt.-% of 4, which is a good ligand loading rate for a potential subsequent transformation of the silver(i) carboxylates into powerful immobilized catalysts. [31][32][33] Immobilized silver(i) salts 7 show remarkable stability when taking into account that stabilization of their homogeneous silver(i) precursors 4 occurred by aggregation, which is necessarily reduced upon covalent immobilization of 4 on the silica surface. The immobilized silver(i) salts 7 start to decompose under light at room temperature within several days; when kept under the exclusion of light they can be stored over a period of a few weeks without decomposition.…”

Section: Immobilizationmentioning

confidence: 99%

Trialkoxysilyl‐Functionalized Silver(I) Carboxylates: New Building Blocks for the Synthesis of Immobilizable and Immobilized Homogeneous Catalysts

et al. 2005

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Partly fluorinated trialkoxysilyl-substituted carboxylic acids (RO) 3 Si(CH 2 ) 3 N(RЈ)C(O)(CF 2 ) 3 COOH (3a: R = Et, RЈ = H; 3b: R = RЈ = Me) have been prepared in a straightforward synthesis from the respective trialkoxysilyl-substituted primary and secondary amines and hexafluoroglutaric anhydride. Treatment with silver(I) oxide yields the corresponding silver carboxylates 4a,b which have been thoroughly characterized in solution and in the solid state, including an X-ray crystallographic analysis of 4a. The molecular structure of 4a consists of archetypal carboxylate-bridged disilver(I) pairs with a strong closed-shell Ag-Ag (d 10 -d 10 ) interaction and a unique intramolecular bond between a silyl ether group and the metal ion. In addition the amide oxygen atoms are involved in

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Access to silica- and monolithic polymer supported CC-coupling catalysts via ROMP: applications in high-throughput screening, reactor technology and biphasic catalysis

Cited by 63 publications

References 47 publications

Self-Assembled Complexes of Non-cross-linked Amphiphilic Polymeric Ligands with Inorganic Species: Highly Active and Reusable Solid-Phase Polymeric Catalysts

Self-Assembled Complexes of Non-cross-linked Amphiphilic Polymeric Ligands with Inorganic Species: Highly Active and Reusable Solid-Phase Polymeric Catalysts

Catalysts Immobilized on Organic Polymeric Monolithic Supports: From Molecular Heterogeneous Catalysis to Biocatalysis

Trialkoxysilyl‐Functionalized Silver(I) Carboxylates: New Building Blocks for the Synthesis of Immobilizable and Immobilized Homogeneous Catalysts

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