211934-69-9Relevant articles and documents
Fluorinated Porous Conjugated Polyporphyrins through Direct C?H Arylation Polycondensation: Preparation, Porosity, and Use as Heterogeneous Catalysts for Baeyer–Villiger Oxidation
Cao, Qiang,Yin, Qing,Chen, Qi,Dong, Zhi-Bing,Han, Bao-Hang
, p. 9831 - 9837 (2017)
By considering the high reactivity of fluorinated iron–porphyrin and good stability of porphyrin-based porous polymers, fluorinated iron–porphyrin conjugated porous polymers (FPOP-3–6) were synthesized through direct C?H arylation polymerization. The obtained materials are chemically and thermally stable, of which FPOP-3 exhibits the highest Brunauer–Emmett–Teller specific surface area (about 840 m2 g?1). For functional studies of the obtained polymers as heterogeneous catalysts, catalytic transformation of cycloketones into lactones by oxygen through Baeyer–Villiger oxidation was used as a model reaction. Fluorinated phenyl substituents of the iron–porphyrin not only are beneficial to the conversion, but also can stabilize the porphyrin to resist catalyst breakdown. The polymer FPOP-3, with high porosity, exhibits the best catalytic efficiency and recycling effect. The recovered catalyst also shows good catalytic activities after recycling three times with a small loss in yield.
Porphyrin Grafting on a Mercapto-Equipped Zr(IV)-Carboxylate Framework Enhances Photocatalytic Hydrogen Production
Diao, Yingxue,Li, Mu-Qing,Xu, Nanfeng,Xu, Zhengtao,Zhu, Xunjin
, p. 12643 - 12649 (2020)
We employ facile aromatic nucleophilic substitution between the mercapto (-SH) and arylfluoro (Ar-F) groups to achieve extensive and robust cross-linking of a coordination host by porphyrin guests that also serve the purpose of versatile postsynthetic fun
Iron(III) Complexation with Galactodendritic Porphyrin Species and Hydrocarbons’ Oxidative Transformations
Castro, Kelly A. D. F.,Westrup, Kátia C. M.,Silva, Sandrina,Pereira, Patrícia M. R.,Sim?es, Mário M. Q.,Neves, Maria da Gra?a P. M. S.,Cavaleiro, José A. S.,Tomé, Jo?o P. C.,Nakagaki, Shirley
, p. 2857 - 2869 (2021)
The iron metalation of the known free-base porphyrins H2P2 and H2P3, obtained by structural modification of the well-known TPPF20 (H2P1) with galactose dendritic units, gave the corresponding iron(III) porphyrin complex FeP2 and the solid hybrid material FeP3S. Their synthesis, characterization and catalytic efficacy toward the oxidation of the organic substrates (Z)-cyclooctene, cyclohexane and heptane, are reported. In this work, the possibility to modulate selectivity and chemical efficiency of the catalytic system by using simple and more sophisticated metalloporphyrins is demonstrated. Furthermore, the presence of the galactose dendrimer units at the meso-porphyrin ring positions can tune the oxidation at the terminal positions in linear alkanes. In addition, the FeP3S material was easily recovered and reused at least 3 times for the cyclooctene oxidation. The catalytic performance of material FeP3S, associated with their possibility of reuse, makes this material a promising catalyst.
Rate-Limiting Step of Epoxidation Reaction of the Oxoiron(IV) Porphyrin π-Cation Radical Complex: Electron Transfer Coupled Bond Formation Mechanism
Fujii, Hiroshi,Hada, Masahiko,Ishimizu, Yuri,Ma, Zhifeng
, p. 17687 - 17698 (2021/12/01)
Epoxidation reactions catalyzed by high-valent metal-oxo species are key reactions in various biological and chemical processes. Because the redox potentials of alkenes are higher than those of most high-valent metal-oxo species, the electron transfer (ET
A comparative study of electrocatalytic hydrogen evolution by iron complexes of corrole and porphyrin from acetic acid and water
Zhong, Ya-Qian,Hossain, Md. Sahadat,Chen, Ying,Fan, Qi-Hang,Zhan, Shu-Zhong,Liu, Hai-Yang
, p. 399 - 406 (2019/02/19)
Iron complexes of corrole and porphyrin bearing electron-withdrawing meso-C6F5 groups had been used for the electrocatalytic evolution of hydrogen. In neutral buffer solution, evolution of hydrogen turnover frequency (TOF) values for iron corrole and iron porphyrin were 274 and 233?h?1 at an overpotential of 838?mV versus standard hydrogen electrode (SHE). The corresponding TOF values had dropped sharply to 19.79?h?1 and 14.36?h?1 in acetic acid media at an overpotential of 942?mV versus SHE. Interestingly, hydrogen evolution catalyzed by Fe(III) porphyrin was mainly via an Fe(I)-H intermediate, while a higher valent Fe(III)-H intermediate was observed for Fe(IV) corrole.
Influence of substituents in meso-aryl groups of iron μ-oxo porphyrins on their catalytic activity in the oxidation of cycloalkanes
Tabor, Edyta,Po?towicz, Jan,Pamin, Katarzyna,Bas?g, Sylwia,Kubiak, W?adys?aw
, p. 342 - 349 (2016/10/09)
The aim of this work was to study the effect of substituents on the catalytic activity of iron μ-oxo porphyrins in oxidation of cycloalkanes. Electron-donating or electron-withdrawing substituents were introduced in meso-aryl groups of iron μ-oxo porphyrins. An important part of the work was the characterization of the catalysts, in particular their redox properties. Catalytic performance and selectivity were evaluated using cyclopentane, cyclohexane, and cyclooctane as model compounds. It was shown that not only electron-withdrawing but also electron-donating substituents improved the catalytic performance of iron μ-oxo complexes. Moreover, catalytic activity of iron μ-oxo porphyrins with electron-withdrawing substituents correlated with the half-wave potential E1/2while the catalytic activity of iron μ-oxo porphyrins with electron-donating substituents increased with the decrease of reduction potential ERED.
Iron(III) fluorinated porphyrins: Greener chemistry from synthesis to oxidative catalysis reactions
Rebelo, Susana L. H.,Silva, Andre M. N.,Medforth, Craig J.,Freire, Cristina
, (2016/05/24)
: Iron(III) fluorinated porphyrins play a central role in the biomimetics of heme enzymes and enable cleaner routes to the oxidation of organic compounds. The present work reports significant improvements in the eco-compatibility of the synthesis of 5,10,15,20-tetrakis-pentafluorophenylporphyrin (H2 TPFPP) and the corresponding iron complex [Fe(TPFPP)Cl], and the use of [Fe(TPFPP)Cl] as an oxidation catalyst in green conditions. The preparations of H2 TPFPP and [Fe(TPFPP)Cl] typically use toxic solvents and can be made significantly greener and simpler using microwave heating and optimization of the reaction conditions. In the optimized procedure it was possible to eliminate nitrobenzene from the porphyrin synthesis and replace DMF by acetonitrile in the metalation reaction, concomitant with a significant reduction of reaction time and simplification of the purification procedure. The Fe(III)porphyrin is then tested as catalyst in the selective oxidation of aromatics at room temperature using a green oxidant (hydrogen peroxide) and green solvent (ethanol). Efficient epoxidation of indene and selective oxidation of 3,5-dimethylphenol and naphthalene to the corresponding quinones is observed.
Synthesis of new metalloporphyrin derivatives from [5,10,15,20-tetrakis (pentafluorophenyl)porphyrin] and 4-mercaptobenzoic acid for homogeneous and heterogeneous catalysis
de F. Castro, Kelly A.D.,Sim?es, Mário M.Q.,da Gra?a P.M.S. Neves, Maria,Cavaleiro, José A.S.,Ribeiro, Ronny R.,Wypych, Fernando,Nakagaki, Shirley
, p. 9 - 19 (2018/04/09)
Synthetic metalloporphyrins are catalysts that can efficiently insert oxygen and other atoms such as nitrogen and sulfur in hydrocarbons and in a wide variety of other organic compounds. This work reports on a synthetic strategy to prepare new metalloporphyrins via structural modification of [5,10,15,20-tetrakis (pentafluorophenyl)porphyrin], or [H2(TPFPP)], with 4-mercaptobenzoic acid; it also describes their characterization and catalytic activity. The substituent groups present in the structure of the resulting porphyrins furnished structured solids, which could potentially serve as catalysts in heterogeneous medium. Investigation of the catalytic activity of the new derivatives in the oxidation of (Z)-cyclooctene, cyclohexane, and heptane, under homogeneous conditions, and in the oxidation of (Z)-cyclooctene, in heterogeneous medium, proved that the new metalloporphyrins constituted excellent catalysts for (Z)-cyclooctene epoxidation. As for alkane oxidation, they selectively gave the corresponding alcohol in good yields.
Formation of iron(III) meso-chloro-isoporphyrin as a reactive chlorinating agent from oxoiron(IV) porphyrin π-cation radical
Cong, Zhiqi,Kurahashi, Takuya,Fujii, Hiroshi
, p. 4469 - 4472 (2012/04/23)
Iron(III) isoporphyrin, a tautomer of porphyrin with a saturated meso carbon, is one of the isoelectronic forms of oxoiron(IV) porphyrin π-cation radical, which is known as an important reactive intermediate of various heme enzymes. The isoporphyrin has been believed to be incapable of catalyzing oxygenation and oxidation reactions. Here, we report that an oxoiron(IV) porphyrin π-cation radical can be converted to iron(III) meso-chloro- isoporphyrin in the presence of trifluoroacetic acid and chloride ion. More importantly, this study shows the first evidence that iron(III) meso-chloro-isoporphyrin is an excellent reactive agent for chlorinating aromatic compounds and olefins. The results of this study suggest that the mechanism involves electrophilic chlorination of substrate with iron(III) meso-chloro-isoporphyrin.
Redox potentials of oxoiron(IV) porphyrin π-cation radical complexes: Participation of electron transfer process in oxygenation reactions
Takahashi, Akihiro,Kurahashi, Takuya,Fujii, Hiroshi
, p. 6922 - 6928 (2011/09/20)
The oxoiron(IV) porphyrin π-cation radical complex (compound I) has been identified as the key reactive intermediate of several heme enzymes and synthetic heme complexes. The redox properties of this reactive species are not yet well understood. Here, we report the results of a systematic study of the electrochemistry of oxoiron(IV) porphyrin π-cation radical complexes with various porphyrin structures and axial ligands in organic solvents at low temperatures. The cyclic voltammogram of (TMP)FeIVO, (TMP = 5,10,15,20-tetramesitylporphyrinate), exhibits two quasi-reversible redox waves at E1/2 = 0.88 and 1.18 V vs SCE in dichloromethane at -60 °C. Absorption spectral measurements for electrochemical oxidation at controlled potential clearly indicated that the first redox wave results from the (TMP)FeIVO/[(TMP+?)FeIVO]+ couple. The redox potential for the (TMP)FeIVO/[(TMP +?)FeIVO]+ couple undergoes a positive shift upon coordination of an anionic axial ligand but a negative shift upon coordination of a neutral axial ligand (imidazole). The negative shifts of the redox potential for the imidazole complexes are contrary to their high oxygenation activity. On the other hand, the electron-withdrawing effect of the meso-substituent shifts the redox potential in a positive direction. Comparison of the measured redox potentials and reaction rate constants for epoxidation of cyclooctene and demethylation of N,N-dimethylanilines enable us to discuss the details of the electron transfer process from substrates to the oxoiron(IV) porphyrin π-cation radical complex in the oxygenation mechanisms.
