One-pot synthesis of meso-formylporphyrins by SNAr reaction of 5,15-disubstituted porphyrins with (2-pyridyidimethylsilyl)methyllithium

A simple, one-pot procedure that converts 5,15-substituted porphyrins into the corresponding meso-formylated porphyrins has been developed. The method, based on a new synthetic concept for functionalized porphyrins utilizing the (2-pyridyldimethylsilyl)methyl group as a latent formyl functionality, affords the desired product in good yield and is especially appropriate for the direct formylation of free base porphyrins, which has never been achieved by known methods.