New substrates for ruthenium-catalyzed ROMP

ORGN 366

Jae Chul Lee,, Kathlyn A. Parker, and Nicole S. Sampson, Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794-3400
Synthetic multivalent ligands are widely used to investigate receptor-ligand interactions in biological systems. One widely used approach for the synthesis of multivalent ligands is ring-opening metathesis polymerization (ROMP) of strained alkenes, e.g., 5-exo-norbornene carboxylic acid (exo-bicyclo[2.2.1]-hept-5-ene-2-carboxylic acid) derivatives using ruthenium (Grubbs) procatalysts. The ROMP of these derivatives provides polymers with dispersities close to 1 but, for each monomer incorporated, there are two regioisomeric and two stereoisomeric possibilities. Consequently, there may be hundreds of thousands to millions of stereoisomers depending on the length of the polymer. Here, we report the synthesis and ROMP of cyclobutenecarbonyl glycine methyl ester (1) ([(cyclobut-1-enecarbonyl)-amino]-acetic acid methyl ester) using (H2IMes)(3-bromopyridine)2(Cl)2Ru=CHPh. The ruthenium-catalyzed ring-opening of cyclobutene 1 is regioselective to yield polymers with a polybutene backbone in which the stereoisomeric ambiguities are reduced.

Bioorganic, Metal-Mediated Reactions, and Molecular Recognition
8:00 PM-10:00 PM, Tuesday, 30 August 2005 Washington DC Convention Center -- Hall A, Poster

8:00 PM-10:00 PM, Monday, 29 August 2005 Washington DC Convention Center -- Hall A, Sci-Mix

Division of Organic Chemistry

The 230th ACS National Meeting, in Washington, DC, Aug 28-Sept 1, 2005