Synthesis and spectroscopic properties of porphyrin-substituted uridine and deoxyuridine

A general synthetic route to porphyrin-substituted uridine and 2'-deoxyuridine using Sonogashira coupling with acetylene porphyrins is presented. Both diphenyl and tetraphenyl porphyrins, as free base or zinc metallated, can be attached to the nucleobase. Selective TBDMS protection of the deoxyribose does not affect the coupling reaction. The substituents on the porphyrins render the conjugates soluble either in organic solvents (carboxy esters) or in water (carboxylates). No electronic communication between the chromophore and the nucleobase occurs, as indicated by UV/Vis spectroscopy. In aqueous solution, the absorption of the porphyrins is substantially lower than in organic solvents.