Ring opening metathesis polymerization-derived block copolymers bearing chelating ligands: synthesis, metal immobilization and use in hydroformylation under micellar conditions
Autor: | Siegfried Blechert, Michael R. Buchmeiser, Gajanan Manohar Pawar, Jochen Weckesser |
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Rok vydání: | 2010 |
Předmět: |
chemistry.chemical_classification
catalysis micelles hydrophilic polymers Iodide Organic Chemistry Micelle Full Research Paper Catalysis lcsh:QD241-441 chemistry.chemical_compound Chemistry block copolymers Monomer lcsh:Organic chemistry chemistry Polymer chemistry Copolymer Ring-opening metathesis polymerisation lcsh:Q metathesis lcsh:Science Selectivity Hydroformylation |
Zdroj: | Beilstein Journal of Organic Chemistry Beilstein Journal of Organic Chemistry, Vol 6, Iss 1, p 28 (2010) |
ISSN: | 1860-5397 |
Popis: | Norborn-5-ene-(N,N-dipyrid-2-yl)carbamide (M1) was copolymerized with exo,exo-[2-(3-ethoxycarbonyl-7-oxabicyclo[2.2.1]hept-5-en-2-carbonyloxy)ethyl]trimethylammonium iodide (M2) using the Schrock catalyst Mo(N-2,6-Me2-C6H3)(CHCMe2Ph)(OCMe(CF3)2)2 [Mo] to yield poly(M1-b-M2). In water, poly(M1-b-M2) forms micelles with a critical micelle-forming concentration (cmc) of 2.8 × 10−6 mol L−1; Reaction of poly(M1-b-M2) with [Rh(COD)Cl]2 (COD = cycloocta-1,5-diene) yields the Rh(I)-loaded block copolymer poly(M1-b-M2)-Rh containing 18 mg of Rh(I)/g of block copolymer with a cmc of 2.2 × 10−6 mol L−1. The Rh-loaded polymer was used for the hydroformylation of 1-octene under micellar conditions. The data obtained were compared to those obtained with a monomeric analogue, i.e. CH3CON(Py)2RhCl(COD) (C1, Py = 2-pyridyl). Using the polymer-supported catalyst under micellar conditions, a significant increase in selectivity, i.e. an increase in the n:iso ratio was accomplished, which could be further enhanced by the addition of excess ligand, e.g., triphenylphosphite. Special features of the micellar catalytic set up are discussed. |
Databáze: | OpenAIRE |
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