Xq. Jiang et Km. Smith, SYNTHESES OF SOME BETA-SUBSTITUTED ALKYNE PORPHYRINS RELATED TO PROTOPORPHYRIN-IX, Journal of the Chemical Society. Perkin transactions. I, (13), 1996, pp. 1601-1606
beta-Acetylporphyrins (e.g. 20, 35, 39) have been treated with Vilsmei
er complex (POCl3-DMF) to afford beta-(1-chloro-2-formylvinyl)porphyri
ns (23, 36, 41); with an excess of KOH in methanol these compounds wer
e transformed into the corresponding alkynylporphyrins (17, 37, 38). T
he bis-alkynyl-porphyrin 17 was transformed into the corresponding hem
in 25 by treatment with iron(II) chloride.