FUNCTIONALIZATION OF PORPHYRINS THROUGH C-C BOND FORMATION REACTIONS WITH FUNCTIONAL GROUP-BEARING ORGANOMETALLIC REAGENTS

摘要

Interest in the chemistry of porphyrins and related tetrapyrrolic macrocycles has increased greatly in recent years because of the importance of these compounds in many areas of chemistry, biology, and material sciences. Consequently, the development of efficient synthetic strategies and intermediates for the preparation of porphyrin derivatives with a variety of peripheral substituents has become an active field of research. Functionalized porphyrins, which contain chemically reactive functional groups such as esters, amides, nitriles, and formyl groups on the porphyrin core and as peripheral substituents, are potential precursors for more complicated porphyrin derivatives. However, current methods for synthesizing functionalized porphyrins generally suffer from limitations, including tedious multi-step preparation, laborious chromatographic purification, and low yields. This review describes our recent efforts to address some of these challenges using the following strategies: (1) a palladium-catalyzed Negishi cross-coupling reaction of halogenated porphyrins with functional group-bearing organozinc reagents, and (2) the silylmethylation of porphyrins with silylmethyllithium and magnesium reagents, where the silylmethyl groups can be used as protected analogs of various chemically reactive functionalities, such as formyl and hydroxymethyl groups.