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.

An efficient one-pot procedure which converts 5,15-disubstituted porphyrins into their corresponding meso acyl-, alkoxycarbonyl-, and carbamoyl-substituted meso-formylporphyrins has been developed, where the procedure involves a sequential S(N)Ar reaction of porphyrins with PyMe(2)SiCH(2)Li, followed by acylation or related reactions and oxidation.

Alkoxycarbonyl-, and Carbamoyl-Substituted meso-Formylporphyrins. -A series of substituted meso-formylporphyrins (IV) and (VI) is prepared in good yields via nucleophilic substitution of porphyrins (I) with lithiumorganic compound (II) as a latent formyl group, subsequent acylation or reaction with isocyanates followed by hydrolysis and oxidation. -(TAKANAMI, T.; WAKITA, A.; MATSUMOTO, J.; SEKINE, S.; SUDA*, K.; Chem.

2008 Porphyrin derivatives R 0130 One-Pot Synthesis of meso-Formylporphyrins by SNAr Reaction of 5,15-Disubstituted Porphyrins with (2-Pyridyldimethylsilyl)methyllithium. -The reaction is general for substrates bearing aliphatic and aromatic substituents, including sterically demanding ones. -(TAKANAMI*, T.; WAKITA, A.; SAWAIZUMI, A.; ISO, K.; ONODERA, H.; SUDA, K.; Org. Lett. 10 (2008) 4, 685-687; Meiji Pharm. Univ., Kiyose, Tokyo 204, Japan; Eng.) -R. Steudel 30-111