Benzo[b]furan synthesis via palladium-catalysed intramolecular o-arylation of enolates

ORGN 124

Dawn Taylor, chpdt@bath.ac.uk1, Michael C. Willis, m.c.willis@bath.ac.uk1, and Adam T. Gillmore2. (1) Department of Chemistry, University of Bath, Bath, BA2 7AY, United Kingdom, (2) Chemical Research and Development Department, Pfizer Global Research and Development, Sandwich, Kent, CT13 9NJ, United Kingdom
The benzofuran ring system features in a variety of molecules responsible for a diverse range of biological responses. We wished to develop a new synthesis of benzofurans incorporating a key intramolecular palladium catalysed C-O bond formation in which a nucleophilic oxygen atom of an enolate is coupled with a halo-substituted arene ring 2 to give the desired benzofuran 3. In addition, a second palladium catalysed procedure can be used to prepare the required arylated ketones 1, providing, in certain cases, a one-pot synthesis of benzofurans from simple ketones and 1,2-dihaloarenes. Both cyclic and acyclic ketones as well as substituted aryl halides have proven efficient substrates.

The poster will detail the range of results obtained, highlighting a novel one-pot two-ligand approach to the synthesis of the benzofuran moiety. Application of this strategy to a new intramolecular palladium catalysed thio-enolate coupling reaction, leading to the synthesis of benzothiophenes, will also be discussed.

 

Heterocycles, Aromatics, Materials, Devices, Switches, Combinatorial Chemistry, Metal-Mediated Reactions
8:00 PM-10:00 PM, Sunday, 13 March 2005 Convention Center -- Hall D, Poster

Division of Organic Chemistry

The 229th ACS National Meeting, in San Diego, CA, March 13-17, 2005