Ma. Faustino et al., NEW NAPHTHOCHLORINS FROM THE INTRAMOLECULAR CYCLIZATION OF BETA-VINYL-MESO-TETRAARYLPORPHYRINS, Tetrahedron letters, 36(33), 1995, pp. 5977-5978
Treatment of nickel(II) beta-vinyl-meso-tetraphenylporphyrins with a d
ilute solution of sulfuric acid affords new naphthochlorins that resul
t from an intramolecular cyclization involving the vinyl group and the
ortho position of the adjacent phenyl ring. These naphthochlorins are
very stable compounds and exhibit strong absorptions in the 670 nm re
gion of the visible spectrum.