STEPWISE SYNTHESES OF BISPORPHYRINS, BISCHLORINS, AND BISCORROLES, AND OF PORPHYRIN-CHLORIN AND PORPHYRIN-CORROLE HETERODIMERS

The stepwise syntheses and characterization of a series of symmetrical and unsymmetrical bisporphyrins, bischlorins, and biscorroles, and of porphyrin-chlorin and porphyrin-corrole dyads possessing ethylene, ph enyl, and stilbene linking units are described. The methodology for sy nthesis of 10-substituted corroles 2 and their cobalt complexes 9 via a,c-biladiene salts 1 was first developed, and then extended to provid e biscorroles (e.g., 4 and 5) linked through the 10-positions with phe nyl linker units. Using a similar methodology, phenyl-linked corrole-p orphyrin dyads 28 and 30 were also prepared. By way of intermediate ph enyl-linked unsymmetrical bisdipyrromethanes, a completely unsymmetric al heterobimetallic bisporphyrin system, 45, was synthesized. Low-vale nt titanium coupling (McMurry) reactions were used to prepared stilben e-linked bisdipyrromethanes (e.g., 46) which were subsequently transfo rmed into stilbene-linked bisporphyrins (e.g., 48). McMurry cross-coup ling reactions of porphyrins bearing p-formylphenyl substituents also afforded an unsymmetrically substituted bisporphyrinylstilbene, 60, as well as the corresponding homodimers 56 and 59. Likewise, McMurry cro ss-coupling of a p-formylphenyl-substituted porphyrin, 62, with a form ylchlorin, 63, afforded a stilbene-linked bisporphyrin, 64, a bischlor in, 66, and a novel porphyrin-chlorin heterodimer, 65. All novel produ cts were characterized by H-1 NMR, IV-vis, and mass spectroscopy and e lemental analysis. X-ray structural information was also obtained for the zinc/nickel bisporphyrin 45 and for the bis-nickel porphyrin-chlor in 65.