Regioselective formylation of rhenium-oxo and gold corroles: substituent effects on optical spectra and redox potentials.

Vilsmeier-Haack formylation of ReO and Au meso-triarylcorroles over 16-18 hours affords moderate to good yields (47-65%) of the ReO-3-formyl and Au-3,17-diformyl derivatives in a highly regioselective manner. Formylation was found to effect substantial upshifts for redox potentials (especially the reduction potentials) as well as significant to dramatic redshifts for both the Soret and Q bands.