The Open Organic Chemistry Journal

2008, 2 : 58-64
Published online 2008 June 9. DOI: 10.2174/1874095200801020058
Publisher ID: TOOCJ-2-58

A Solvent-Induced Reversal of Regioselectivity in the Suzuki Coupling of Pyrrole Esters

Yanan Zhang and Scott T. Handy
Department of Chemistry, Middle Tennessee State University, Murfreesboro, TN 37132.

ABSTRACT

During a study of the regioselectivity of the Suzuki coupling of dihalopyrrole esters, the first instance of a reversal of regioselectivity based upon a change in reaction solvent has been observed. It is believed that this change in regioselectivity is due to a change in solvation of the pyrrole ester, since a change in chemical shift values is observed for the C3 and C5 protons upon going from DMF to chloroform to 3:1 benzene/methanol. An attempted application of this regioselectivity to the synthesis of the lamellarin family of natural products is reported as well.