Synthesis and Characterization of Blocked and Ligand-Appended Hemes Derived from Atropisomeric meso-Diphenylporphyrins

Article abstract of DOI:10.1021/ja00290a027

The synthesis of a series of sterically blocked and imidazole-appended meso-diphenyletioporphyrins is described.These hybrid porphyrins have good solubility and spectroscopic properties of β-substituted porphyrins as well as the orientation specificity of ortho-position-derivatized tetraphenylporphyrins.The effectiveness of the blocking groups is demonstrated by ferric hemin hydroxide formation in the doubly protected trans-5,15-bis-2,8,12,18-tetraethyl-3,7,13,17-tetramethylporphine, characterized by UV-visible, 1H NMR, and IR spectra and cyclic voltammetry.The advantage of the m-benzyl linkage in enforcing imidazole coordination to ferric hemes is demonstrated by 1H NMR studies on various type of imidazole-appended heme complexes.Several potential binucleating systems have also been prepared by incorporating nonheme chelating ligands to the hybrid porphyrins.