Beta-perfluoroalkyltetraarylporphyrins: Synthesis And Intramolecular Cyclization Reactions

Porphyrins dominate great applications in various scientific fields such as biomimetic models for photosynthesis, medical application and material chemistry. Introduction of fluorine or fluoroalkyl group at periphery of porphyrins has deep effect on the properties of the ligands. This dissertation is focused on the synthesis of the B-perfluoroalkyltetraarylporphyrins and their intramolecular cyclization reactions. It consists of three parts.The first part of this dissertation: Fluoroalkylation of Porphyrins: Synthesis and Reaction of β-perfluoroalkyltetraarylporphyrins.We did some research on the fluoroalkylation on tetraarylporphyrins. It was found that sulfinatodehalogenation method is most suitable to introduce perfluoroalkyl group onto B, B-double carbon-carbon bond of tetraarylporphyrins. Treatment of meso-tetraarylporphyrins with perfluoroalkyl iodides in the presence of Na2S2O4/NaHCO3 in DMSO/CH2Cl2 at 30C for several hours gives the corresponding 2-perfluoroalkylporphyrins. Electrophilic substitution on2-perfluoroalkylporphyrins occurs at antipodal position. Nucleophilic attack on 2-perfluoroalkylporphyrins with dimethyl malonate, diethyl malonate, malonitrile, or cyano acetate (Nu) anion results in the formation of (E)-3-Nu-2-perfluoroalkyl-(methylenyl)chlorins.The second part of this dissertation: Synthesis of meso, β and β, P -Perflouroethersulfonyl Ester Linked Diporphyrins.We synthesized of β-fluorosulfonylperfluoroetheryltetraarylporphyrins. The β-fluorosulfonylperfluoroetheryltetraarylporphyrins reacted with5-(4-Hydroxyphenyl)-10,15,20-triphenylporphyrin and BINOL to afford meso, β- or β, β-Perfluoroethersulfonyl ester linked diporphyrins. Treatment of the diporphyrins with zinc acetate in CHCl3/CH3OH at refluxing for 1 hr gave diporphinatozinc. UV-vis absorption and fluorescence data of meso-β and β-β diporphyrins were determined and discussed. The β-fluorosulfonylperfluoroetheryltetraarylporphyrins reacted with imidazolyl-sodium or benzoimidazolyl-sodium to give thecorresponding 6-Perfluoroethersulfonylamide porphyrins.The third part of this dissertation: The intramolecular cyclization reactions of Porphyrin β-perfluoroalkylradicals.A content of tetraarylporphyrin and 1,3-diiodohexafluoropane was heated at 55C, in the presence of Na2S2O4/NaHCO3 in DMSO/CH2Cl2(1:2/V:V) for 22h, a mixture of unexpected 5- and 8- endo cyclization product was obtained. The 5- endo cyclization product is the perfluoroproane linked the β, β-position in one pyrrole ring and the 8-endo cyclization product is the perfluoroproane linked one β-position of the pyrrole ring with one ortho position of the meso phenyl ring. X -ray crystallography determination of β- and β- endo cyclization products strongly supported this conclusion. It showed that 2-(3-iodioheptfluoropropanyl)-tetraarylporphyrin might be the intermediate for the formation of 5- and 8- endo cyclization products. The inhibition experiment were carried out . Suppression by p-dinitrobenzene (p-DNB) and hydroquinone demonstrated that the reaction occurred by single electron-transfer mechanism. Under the similar conditions, 1,4-diiodooctafluorobutane reacted with tetraarylporphyrin to afford 6- endo cyclization product, i.e. perfluorobutane linked the β , β-position in one pyrrole ring. Similarly 1,5-diiododecafluoropentane reacted with tetraarylporphyrin to give 7-endo cyclization product, i.e. perfluoroalkyl-linked the β , β -position in one pyrrole ring. However when difluorodiiodomethane or 1,2-diiodotetrafluoroethane was allowed to react with tetraarylporphyrin, the desired cyclization compound were not obtained. Using 1-chloro-2-iodotetrafluoroethane inste...