Lindsey-Rothemund synthesis of meso-tetraaryloxybenziporphyrins

ORGN 537

Jessica A. El-Beck, jaelbec@ilstu.edu and Timothy D. Lash, tdlash@ilstu.edu. Department of Chemistry, Illinois State University, Normal, IL 61790-4160

Carbaporphyrins are porphyrin analogues with carbocyclic rings in place of one or more of the usual pyrrole units. These systems are of considerable interest due to their unusual spectroscopic and chemical properties. Oxybenziporphyrins have been prepared previously by the “3+1” methodology. However, this multistep approach only affords limited quantities of material. In this work, a direct Rothemund-type synthesis of tetraaryloxybenziporphyrins is reported. Dicarbinol 1, pyrrole and benzaldehyde were reacted in the presence of BF3 to give the meso-substituted oxybenziporphyrins 2. These carbaporphyrins react with silver(I) and gold(III) salts under mild conditions to afford the novel organometallic derivatives 3. These metal complexes show enhanced diatropic character in their proton NMR spectra.