Ring opening metathesis polymerization-derived block copolymers bearing chelating ligands: synthesis, metal immobilization and use in hydroformylation under micellar conditions.

ABSTRACT: 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-Me?-C?H?)(CHCMe?Ph)(OCMe(CF?)?)?[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 x 10?? mol L?¹; Reaction of poly(M1-b-M2) with [Rh(COD)Cl]? (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 x 10?? 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. CH?CON(Py)?RhCl(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.

SUBMITTER: Pawar GM 

PROVIDER: S-EPMC2874313 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature