A purification of meso-tetraphenylporphyrin

Rousseau, Kathleen; Dolphin, David

doi:10.1016/s0040-4039(01)92134-3

Cited by 55 publications

(20 citation statements)

References 3 publications

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“…The collected analytical data for N-(4-chlorophenyl)-2-phenylaziridine (16) [76] and N-(4-cyanophenyl)-2-phenylaziridine (20) [77] are in agreement with those reported in the literature. [78] followed by solvent evaporation and purification by flash chromatography on silica (eluent n-hexane/dichloromethane, …”

Section: Generalmentioning

confidence: 99%

The (Porphyrin)ruthenium‐Catalyzed Aziridination of Olefins Using Aryl Azides as Nitrogen Sources

et al. 2007

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Aryl azides have been used as atom-efficient nitrene transfer reagents in the (porphyrin)ruthenium-catalyzed amination of olefins. Several azides, olefins and [Ru(porphyrin)CO] complexes were tested to investigate the scope and limits of the reaction. Quantitative yields and short reaction times were achieved by using terminal olefins and aryl azides bearing electron-withdrawing groups on the aryl moiety. The reactions were influenced by steric factors. Internally disubsti-

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Section: Generalmentioning

confidence: 99%

The (Porphyrin)ruthenium‐Catalyzed Aziridination of Olefins Using Aryl Azides as Nitrogen Sources

et al. 2007

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“…Meso-tetrakis(3,5-di-t-butyl-4-oxo-2,5-cyclohexadienylidene)porphyrinogen host (H1) molecule was prepared by a previously reported method [22][23][24]. Meso-tetraphenylporphine host (H2) (TCI Co. Ltd.) was purified according to a literature method [25]. Synthesis of the host molecule N 21 ,N 23 -bis(4-bromobenzyl)-5,10,15,20-tetrakis(3,5-di-t-butyl-4-oxocyclohexadien-2,5-ylidene)porphyrinogen (H3) has been reported previously [23,24].…”

Section: Methodsmentioning

confidence: 99%

Dynamic Processes in Prochiral Solvating Agents (pro-CSAs) Studied by NMR Spectroscopy

et al. 2014

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Several dynamic processes, including tautomerism and macrocyclic inversion, in 1H-NMR prochiral solvating agents (pro-CSAs) are investigated. Various features of pro-CSA, including modes of interaction for complex formation, stoichiometry, binding strength and temperature effects were compared for three representative pro-CSA molecules. Structural effects of conjugated tetrapyrrole pro-CSA on the mechanism of enantiomeric excess determination are also discussed. Detailed analysis of species (complexes) and dynamic processes occurring in solution and their 1H-NMR spectral manifestations at various temperatures is presented.

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“…Manganese(III) meso-tetraphenyl porphyrin chloride [meso-tetraphenylporphinatomanganese(III) chloride; Mn(III)TPPCl] was prepared as described (10,11). All olefins were purchased from Aldrich and passed through a short column of neutral alumina immediately prior to reaction to remove trace peroxides.…”

Section: Methodsmentioning

confidence: 99%

Epoxidation of olefins by cytochrome P-450 model compounds: mechanism of oxygen atom transfer.

Collman¹,

Brauman²,

Meunier³

et al. 1984

Proc. Natl. Acad. Sci. U.S.A.

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The mechanism of the Mn(III) porphyrincatalyzed epoxidation of olefins by lithium hypochlorite is examined. The active oxidant is thought to be a high-valent manganese-oxo complex. It is shown that a relatively stable intermediate is reversibly formed upon interaction of the olefin and the oxo complex. The decomposition of this intermediate to Mn(III) porphyrin and epoxide is the rate-determining step of the catalytic cycle. Some analogies to the biochemical epoxidation of olefins catalyzed by cytochrome P-450 are discussed.The cytochrome P-450 family of monooxygenase enzymes catalyzes the reaction of molecular oxygen with various small molecules, including alkanes and alkenes (ref. 1; Eq. 1).olefin + 02 + 2H+ + 2e -* epoxide + H20 [1] The active site of these enzymes contains an iron(III) protoporphyrin IX moiety. This is attached to the polypeptide chain through axial ligation of a thiolate anion contributed by a cysteine residue. The active state of cytochrome P-450 is thought to be an iron-oxo complex, with iron formally in the V oxidation state. Scheme I shows the reaction of activated cytochrome P-450 with 2-butene, where the parallelogram represents the dianion of protoporphyrin IX. Ortiz de Montellano and co-workers (2-4) and others (5,6) have shown that olefins also can act as suicide substrates. In one case, Walsh and co-workers (7) demonstrated that the frequency of the suicide event is about 1 in every 250 epoxidation events. This implies that suicide inactivation is a minor side reaction of the normal epoxidation scheme. Because of the potential physiological importance of this process, great interest has been generated in elucidating the molecular mechanism of oxygen atom transfer to olefins.We recently have reported a highly efficient synthetic model system that uses Mn(III) porphyrins and a substituted imidazole ligand to catalyze the transfer of an oxygen atom from hypochlorite to an olefin (8, 9). Epoxides are produced in good yields and at high rates. The postulated catalytic reaction cycle is shown in scheme II, where the oval represents TPP. This paper presents a kinetic investigation of oxygen atom transfer in this system. Such information may lead to a deeper understanding of the atom-transfer reactions of cytochrome P-450 itself. EXPERIMENTALInstrumentation. All NMR spectra were recorded on a Nicolet NMC-300 spectrometer. Analyses of kinetic experiments were performed on a Hewlett-Packard 5880A gas chromatograph fitted with an OV-101 column. Response factors for all compounds were determined by using solutions of known concentration. UV/visible spectra were recorded on a Cary model 219 spectrometer.Materials. Manganese(III) meso-tetraphenyl porphyrin chloride [meso-tetraphenylporphinatomanganese(III) chloride; Mn(III)TPPCl] was prepared as described (10, 11). All olefins were purchased from Aldrich and passed through a short column of neutral alumina immediately prior to reaction to remove trace peroxides. 4'-(Imidazol-1-yl)acetophenone (NAcPhIm) (Aldrich) was twice recrystallize...

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A purification of meso-tetraphenylporphyrin

Cited by 55 publications

References 3 publications

The (Porphyrin)ruthenium‐Catalyzed Aziridination of Olefins Using Aryl Azides as Nitrogen Sources

The (Porphyrin)ruthenium‐Catalyzed Aziridination of Olefins Using Aryl Azides as Nitrogen Sources

Dynamic Processes in Prochiral Solvating Agents (pro-CSAs) Studied by NMR Spectroscopy

Epoxidation of olefins by cytochrome P-450 model compounds: mechanism of oxygen atom transfer.

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