Electron Deficient Porphyrins III. Facile Syntheses of Perfluoroalkylporphyrins Including Water Soluble Porphyrin
作者:Katsuhiro Aoyagi、Toshihiko Haga、Hiroo Toi、Yasuhiro Aoyama、Tadashi Mizutani、Hisanobu Ogoshi
DOI:10.1246/bcsj.70.937
日期:1997.4
A variety of 3-perfluoroalkyl pyrroles were prepared by reaction of β-perfluoroalkyl α,β-unsaturated carbonyl compounds with p-tolylsulfonylmethyl isocyanide in moderate yields. Tetrakis(perfluoroalkyl)porphyrins were readily obtained by oxidative cyclization of 3-alkyl-2-hydroxymethyl-4-perfluoroalkylpyrroles in acidic media, including water-soluble 3,8,13,18-tetrakis(p-carboxybenzyl)-2,7,12,17-tetrakis(trifluoromethyl)porphyrin. The pKa value for the monoprotonation of its inner nitrogen is less than 1, while that of Copro-I is 7.2. Diprotonation at the inner nitrogen occurs only in concd HCl, while the pKa value of the corresponding non-fluoro porphyrin is 4. The reduction potential of 3,8,13,18-tetrakis(p-methoxycarboxybenzyl)-2,7,12,17-tetrakis(trifluoromethyl)porphyrin was shifted by 580 mV to a less negative value.
通过 β-全氟烷基 α、β-不饱和羰基化合物与对甲苯磺酰基甲基异氰酸酯的反应,制备了多种 3-全氟烷基吡咯,收率适中。在酸性介质中,通过 3-烷基-2-羟甲基-4-全氟烷基吡咯的氧化环化反应,很容易得到四(全氟烷基)卟啉,包括水溶性的 3,8,13,18-四(对羧基苄基)-2,7,12,17-四(三氟甲基)卟啉。其内氮的单质子化 pKa 值小于 1,而 Copro-I 的 pKa 值为 7.2。3,8,13,18-四(对甲氧基羧基苄基)-2,7,12,17-四(三氟甲基)卟啉的还原电位向较低的负值移动了 580 mV。