title: Synthesis of 5,10-bis(Trifluoromethyl) Substituted β-Octamethylporphyrins and Central-Metal-Dependent Solvolysis of Their meso-Trifluoromethyl Groups.
abstract: 5,10-Bistrifluoromethyl substituted β-octamethylporphyrins were synthesized via a scrambling side reaction of a dipyrromethane precursor in the presence of a large excess of trifluoroacetic acid. Compared with the trans-analogs, the cis-analogs of meso-trifluoromethyl β-octaalkylporphyrin showed more red-shifted absorption bands. These meso-trifluoromethyl derivatives of β-octaalkylporphyrins underwent smooth metalation, similar to other common porphyrins, however, the corresponding zinc complexes underwent a type of solvolysis, whereby the trifluoromethyl groups were converted into methoxycarbonyl groups by the methanol used as solvent. UV-visible absorption spectra and X-ray crystal structure analyses revealed that the presence of a methoxycarbonyl substituent did not influence the deformation of the molecular framework and its absorption properties; this is because the methoxycarbonyl has a planar and perpendicular geometry, as opposed to the relatively bulky trifluoromethyl substituent.
authors.affiliation: Interdisciplinary Graduate School of Science and Engineering, Shimane University, 1060, Nishikawatsu-cho, Matsue, Shimane 690-8504, Japan. m-suzuki@riko.shimane-u.ac.jp.|Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8675, Japan. m-suzuki@riko.shimane-u.ac.jp.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8675, Japan. sneya@faculty.chiba-u.jp.
authors.forename: Saburo
authors.initials: S
authors.lastname: Neya
authors.affiliation: Interdisciplinary Graduate School of Science and Engineering, Shimane University, 1060, Nishikawatsu-cho, Matsue, Shimane 690-8504, Japan. nishigai@riko.shimane-u.ac.jp.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nishigaichi
mesh_terms: D018360:Crystallography, X-Ray; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008670:Metals / Q000737:chemistry; D008958:Models, Molecular; D011166:Porphyrins / Q000138:chemical synthesis* / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry*; D014269:Trifluoroacetic Acid / Q000737:chemistry; D015032:Zinc / Q000737:chemistry
chemical_list: D006845:Hydrocarbons, Fluorinated; D008670:Metals; D011166:Porphyrins; D011758:Pyrroles; C512015:dipyrromethane; D014269:Trifluoroacetic Acid; D015032:Zinc
keywords: alkoxycarbonyl; porphyrin; solvolysis; trifluoromethyl