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Dalton, Cormac T; Ryan, Kenneth M.; Wall, Valerie M.; Bousquet, Claudine; Gilheany, Declan G.

doi:10.1023/a:1019102003494

Cited by 151 publications

(85 citation statements)

References 52 publications

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“…The lower overall yield (40.5 %) of products from trans-stilbene is best explained in terms of steric constraint at the activating site. [15] Styrene was oxidized to styrene oxide (56.5 %), benzaldehyde (5.7 %), and phenylacetaldehyde (19.8 %), again indicating that either a peroxyl radical or an oxomanganese(IV) species was involved as the epoxidizing agent. Analogous re- , [17] has been invoked in radical-type oxidations to account for the formation of ring-opened products in the [Mn III A C H T U N G T R E N N U N G (salen)]-catalyzed epoxidation of a radical probe.…”

Section: Resultsmentioning

confidence: 97%

Efficient Olefin Epoxidation by Robust Re₄ Cluster‐Supported Mn^III Complexes with Peracids: Evidence of Simultaneous Operation of Multiple Active Oxidant Species, Mn^VO, Mn^IVO, and Mn^IIIOOC(O)R

Lee

Park

et al. 2010

Chemistry A European J

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Two new tetranuclear chalcocyanide cluster complexes, [{Mn(saloph)H2O}4Re4Q4(CN)12]⋅4 CH3OH⋅ 8 H2O (saloph = N,N'-o-phenylenebis(salicylidenaminato), Q = Se (1-Se), Te (2-Te)), have been synthesized by the diffusion of a methanolic solution of [PPh4]4[Re4Q4(CN)12] into a methanolic solution of [Mn(saloph)](+). The structure of 2-Te has been determined by X-ray crystallography. These rhenium cluster-supported [Mn(III)(saloph)] complexes have been found to efficiently catalyze a wide range of olefin epoxidations under mild experimental conditions in the presence of meta-chloroperbenzoic acid (mCPBA). Olefin epoxidation by these catalysts is proposed to involve the multiple active oxidants Mn(V)=O, Mn(IV)=O, and Mn(III)-OOC(O)R. Evidence in support of this interpretation has been derived from reactivity and Hammett studies, H2(18)O-exchange experiments, and the use of peroxyphenylacetic acid as a mechanistic probe. Moreover, it has been observed that the participation of Mn(V)=O, Mn(IV)=O, and Mn(III)-OOC(O)R can be controlled by changing the substrate concentration. This mechanism provides the greatest congruity with related oxidation reactions that employ certain Mn complexes as catalysts.

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Section: Resultsmentioning

confidence: 97%

Efficient Olefin Epoxidation by Robust Re₄ Cluster‐Supported Mn^III Complexes with Peracids: Evidence of Simultaneous Operation of Multiple Active Oxidant Species, Mn^VO, Mn^IVO, and Mn^IIIOOC(O)R

Lee

Park

et al. 2010

Chemistry A European J

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“…Many transition-metal catalysts have been used to carry out this transformation, including high oxidation state oxido complexes (methyltrioxidorhenium, dioxido derivatives of Mo and W), [3][4][5][6][7] bisA C H T U N G T R E N N U N G (peroxido) complexes [(L 1 )(L 2 )MO(O 2 ) 2 ] (M= Mo, W), [8] polyoxometallates, [9][10][11] a variety of oxido complexes generated in situ from Fe and Mn porphyrin, salen, and other coordination compounds. [12][13][14][15] The mechanism of this reaction has been, and continues to be, a controversial subject. In many cases, a mechanism related to that accepted for organic peracids is proposed [16] (Scheme 1 a).…”

Section: Introductionmentioning

confidence: 99%

A Computational Study of the Olefin Epoxidation Mechanism Catalyzed by Cyclopentadienyloxidomolybdenum(VI) Complexes

Comas‐Vives

Lledós

Poli

2010

Chemistry A European J

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A DFT analysis of the epoxidation of C(2)H(4) by H(2)O(2) and MeOOH (as models of tert-butylhydroperoxide, TBHP) catalyzed by [Cp*MoO(2)Cl] (1) in CHCl(3) and by [Cp*MoO(2)(H(2)O)](+) in water is presented (Cp*=pentamethylcyclopentadienyl). The calculations were performed both in the gas phase and in solution with the use of the conductor-like polarizable continuum model (CPCM). A low-energy pathway has been identified, which starts with the activation of ROOH (R=H or Me) to form a hydro/alkylperoxido derivative, [Cp*MoO(OH)(OOR)Cl] or [Cp*MoO(OH)(OOR)](+) with barriers of 24.9 (26.5) and 28.7 (29.2) kcal mol(-1) for H(2)O(2) (MeOOH), respectively, in solution. The latter barrier, however, is reduced to only 1.0 (1.6) kcal mol(-1) when one additional water molecule is explicitly included in the calculations. The hydro/alkylperoxido ligand in these intermediates is eta(2)-coordinated, with a significant interaction between the Mo center and the O(beta) atom. The subsequent step is a nucleophilic attack of the ethylene molecule on the activated O(alpha) atom, requiring 13.9 (17.8) and 16.1 (17.7) kcal mol(-1) in solution, respectively. The corresponding transformation, catalyzed by the peroxido complex [Cp*MoO(O(2))Cl] in CHCl(3), requires higher barriers for both steps (ROOH activation: 34.3 (35.2) kcal mol(-1); O atom transfer: 28.5 (30.3) kcal mol(-1)), which is attributed to both greater steric crowding and to the greater electron density on the metal atom.

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“…Among these reported Schiff base cobalt(II) complexes catalysts were known to bind dioxygen more or less reversibly and therefore frequently studied as model compounds for natural oxygen carrier and for their use in O2 storage, as well as in organic syntheses due to their catalytic properties under mild conditions [13,14]. Copper(II) complex with a tridentate imine, was revealed an efficient catalyst for oxidation of phenol, cyclohexene, styrene and benzyl alcohol using hydrogen peroxide and tert-butyl hydroperoxide as oxidant in homogeneous reaction [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Study of Catalytic Activity of Silica Supported Schiff Base Complexes

Deshmukh¹,

Mahind²,

Waghmode³

et al. 2017

Asian J. Chem.

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The catalytic activity of silica supported Schiff base metal complexes have been studied for the oxidation of benzyl alcohol, using hydrogen peroxide, which gave benzaldehyde as a major product. Silica supported Schiff base complexes gave better results compared to unsupported Schiff base complexes. Schiff base metal complexes such as Cr(VI), Mo(VI) and W(VI) have played significant role to enhance their conversion and selectivity. Among these Cr(VI) showed better conversion.

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Cited by 151 publications

References 52 publications

Efficient Olefin Epoxidation by Robust Re₄ Cluster‐Supported Mn^III Complexes with Peracids: Evidence of Simultaneous Operation of Multiple Active Oxidant Species, Mn^VO, Mn^IVO, and Mn^IIIOOC(O)R

Efficient Olefin Epoxidation by Robust Re₄ Cluster‐Supported Mn^III Complexes with Peracids: Evidence of Simultaneous Operation of Multiple Active Oxidant Species, Mn^VO, Mn^IVO, and Mn^IIIOOC(O)R

A Computational Study of the Olefin Epoxidation Mechanism Catalyzed by Cyclopentadienyloxidomolybdenum(VI) Complexes

Study of Catalytic Activity of Silica Supported Schiff Base Complexes

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Untitled

Cited by 151 publications

References 52 publications

Efficient Olefin Epoxidation by Robust Re4 Cluster‐Supported MnIII Complexes with Peracids: Evidence of Simultaneous Operation of Multiple Active Oxidant Species, MnVO, MnIVO, and MnIIIOOC(O)R

Efficient Olefin Epoxidation by Robust Re4 Cluster‐Supported MnIII Complexes with Peracids: Evidence of Simultaneous Operation of Multiple Active Oxidant Species, MnVO, MnIVO, and MnIIIOOC(O)R

A Computational Study of the Olefin Epoxidation Mechanism Catalyzed by Cyclopentadienyloxidomolybdenum(VI) Complexes

Study of Catalytic Activity of Silica Supported Schiff Base Complexes

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Efficient Olefin Epoxidation by Robust Re₄ Cluster‐Supported Mn^III Complexes with Peracids: Evidence of Simultaneous Operation of Multiple Active Oxidant Species, Mn^VO, Mn^IVO, and Mn^IIIOOC(O)R

Efficient Olefin Epoxidation by Robust Re₄ Cluster‐Supported Mn^III Complexes with Peracids: Evidence of Simultaneous Operation of Multiple Active Oxidant Species, Mn^VO, Mn^IVO, and Mn^IIIOOC(O)R