Synthesis and Utility of Novel C-meso-Glycosylated Metalloporphyrins

Novel hybrid porphyrins bearing two and four suitably protected glycosidic units appended at the meso positions of the central macrocycle through robust carbon–carbon bonds have been constructed and characterized. Metallation of these constructs with certain bivalent metal ions then produced a series of porphyrinato entities which had all the sugar protecting groups removed to arrive at the corresponding water soluble porphyrin–sugar hybrid species. It is noteworthy that two palladium derivatives, compounds 6 and 10, proved to be efficient reagents for the selective cleavage of double strand DNA into form II nicked circular DNA upon exposure to visible light at room temperature in aqueous media.