Parallel synthesis of unsymmetrically substituted tetraphenyl porphyrins on Wang resin

A method for synthesizing combinatorial libraries of unsymmetrically substituted tetra-meso-phenyl porphyrins on polystyrene based resin is described. Attachment of 5,15-dibromo-10-(4-hydroxyphenyl)-20-(4-nitrophenyl)porphyrin onto brominated Wang resin gave a convenient scaffold for the synthesis of photoactive porphyrin libraries with three points for generating diversity. An array of nine TPP derivatives was prepared by sequential Suzuki coupling/nitro-reduction and acylation protocols.