Mechanism of oxidation of organic sulphides by oxo(salen)manganese(v) complexes

Chellamani, Arunachalam; Alhaji, Nainamohamed Ismail; Rajagopal, Seenivasan; Sevvel, Ranganathan; Srinivasan, C.

doi:10.1016/0040-4020(95)00825-s

Cited by 67 publications

(63 citation statements)

References 73 publications

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“…Although, we have assumed the active manganese species to be reactive (salen)Mn(V)oxo intermediate, [(salen)Mn v =O], by comparing the present spectral observation with the previous reports [41], we could not isolate this active species. It is pertinent to point out that to date no (salen)Mn(V)oxo species have yielded to structural characterization, although Groves et al and others have characterize oxo manganese (V) porphyrin complexes in recent years [42].…”

Section: Oxo-manganese(v) Species As the Reactive Intermediatementioning

confidence: 37%

Effect of bulky substitution on catalytic activity of a manganese salen complex used in biomimetic alkene epoxidation and alkane hydroxylation with sodium periodate

Mirkhani

Tangestaninezhad

Bahramian

2008

JICS

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The catalytic activity of Mn(salen)Cl containing tert-pentyl groups at the 3,5-positions of the salen ligand in the epoxidation of alkenes and hydroxylation of alkanes was studied at room temperature, using sodium periodate as an oxygen source. The effects of various axial ligands were investigated in the epoxidation of cyclooctene. Imidazole, as a strong -donor ligand, was the best axial ligand. The effect of different solvents was studied in the epoxidation of cyclooctene in CH 3 CN/H 2 O solvent mixture. The epoxidation reactions of cyclooctene by different oxygen donors including NaIO 4 , Bu 4 NIO 4 , KHSO 5 , H 2 O 2 , H 2 O 2 /urea, NaOCl and tert-BuOOH were also studied and NaIO 4 was selected as oxygen source. The presence of bulky substituents in the 3,5-positions of the salen ligand was found to increase the catalytic activity of this complex.

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Section: Oxo-manganese(v) Species As the Reactive Intermediatementioning

confidence: 37%

Effect of bulky substitution on catalytic activity of a manganese salen complex used in biomimetic alkene epoxidation and alkane hydroxylation with sodium periodate

Mirkhani

Tangestaninezhad

Bahramian

2008

JICS

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“…As the isolation of pure oxo(salen)manganese(V) complexes is difficult [7][8][9][10]15,18], they were generated in situ for the studies reported here.…”

Section: Oxidative Conversion Of Manganese(iii) To Oxomanganese(v) Spmentioning

confidence: 99%

“…We have initiated a systematic study on the oxygenation reactions of the organic sulfides and sulfoxides with oxometal complexes by taking Cr, Mn and Ru as metal ions. We have reported the mechanism of oxidation of organic sulfides [7][8][9] and sulfoxides [10] with PhIO catalyzed by (salen)Mn III complexes and also the successful application of the reactivity-selectivity principle (RSP) to these oxidation reactions. The mechanistic studies of (1)…”

Section: Introductionmentioning

confidence: 99%

Mechanism of oxidation of aryl methyl sulfoxides with sodium hypochlorite catalyzed by (salen)MnIII complexes

Chellamani

Harikengaram

2006

Journal of Molecular Catalysis A: Chemical

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“…[44] As shown in Table 2, the rate constants for gas-phase sulfoxidation decline from thioanisoles to dimethylsulfide, a trend similarly found in solution and considered to demonstrate a single ET process. [45] Recent theoretical calculations revealed that Cpd I models with thiolate or imidazole proximal ligands react with dimethylsulfide via a concerted, single-step OAT, with a ligand-dependent spin-state selectivity.…”

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confidence: 99%

Biomimetic Oxidation Reactions of a Naked Manganese(V)–Oxo Porphyrin Complex

Lanucara

Crestoni

2011

Chemistry A European J

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The intrinsic reactivity of a manganese(V)-oxo porphyrin complex, a typically fleeting intermediate in catalytic oxidation reactions in solution, has been elucidated in a study focused on its gas-phase ion-chemistry. The naked high-valent Mn(V)-oxo porphyrin intermediate 1 ([(tpfpp)Mn(V)O](+); tpfpp=meso-tetrakis(pentafluorophenyl)porphinato dianion), has been obtained by controlled treatment of [(tpfpp)Mn(III)]Cl (2-Cl) with iodosylbenzene in methanol, delivered in the gas phase by electrospray ionization and assayed by FT-ICR mass spectrometry. A direct kinetic study of the reaction with selected substrates, each containing a heteroatom X (X=S, N, P) including amines, sulfides, and phosphites, was thus performed. Ionic products arising from electron transfer (ET), hydride transfer (HT), oxygen-atom transfer (OAT), and formal addition (Add) may be observed, with a predominance of two-electron processes, whereas the product of hydrogen-atom transfer (HAT), [(tpfpp)Mn(IV)OH](+), is never detected. A thermochemical threshold for the formation of the product radical cation allows an evaluation of the electron-transfer ability of a Mn(V)-oxo complex, yielding a lower limit of 7.85 eV for the ionization energy of gaseous [(tpfpp)Mn(IV)O]. Linear free-energy analyses of the reactions of para-substituted N,N-dimethylanilines and thioanisoles indicate that a considerable amount of positive charge is developed on the heteroatom in the oxidation transition state. Substrates endowed with different heteroatoms, but similar ionization energy display a comparable reaction efficiency, consistent with a mechanism initiated by ET. For the first time, the kinetic acidity of putative hydroxo intermediates playing a role in catalytic oxidations, [(tpfpp)Fe(IV)OH](+) and [(tpfpp)Mn(IV)OH](+), has been investigated with selected reference bases, revealing a comparatively higher basicity for the ferryl, [(tpfpp)Fe(IV)O], with respect to the manganyl, [(tpfpp)Mn(IV)O], unit. Finally, the neat association reaction of 2 has been studied with various ligands showing that harder ligands are more strongly bound.

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Mechanism of oxidation of organic sulphides by oxo(salen)manganese(v) complexes

Cited by 67 publications

References 73 publications

Effect of bulky substitution on catalytic activity of a manganese salen complex used in biomimetic alkene epoxidation and alkane hydroxylation with sodium periodate

Effect of bulky substitution on catalytic activity of a manganese salen complex used in biomimetic alkene epoxidation and alkane hydroxylation with sodium periodate

Mechanism of oxidation of aryl methyl sulfoxides with sodium hypochlorite catalyzed by (salen)MnIII complexes

Biomimetic Oxidation Reactions of a Naked Manganese(V)–Oxo Porphyrin Complex

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