Ruthenium-catalyzed oxidative dehalogenation of organics

Bressan, M.; d’Alessandro, Nicola; Liberatore, Lolita; Morvillo, Antonino

doi:10.1016/s0010-8545(99)00024-7

Cited by 40 publications

(54 citation statements)

References 39 publications

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“…Indeed, the preparation of 1,3-diarylimidazolium ions from glyoxal, an aromatic amine, and paraformaldehyde under aqueous acidic conditions usually leads to the concomitant formation of highly colored ionomer by-products that are very difficult to separate from the desired salt, particularly when working on a small laboratory scale [62,63]. We have applied this method to the synthesis of compounds (11) and (12). We have applied this method to the synthesis of compounds (11) and (12).…”

Section: Synthesis Of New N-heterocyclic Carbene Precursorsmentioning

confidence: 99%

Synthesis and Application of New N-Heterocyclic Carbene Ruthenium Complexes in Catalysis: A Case Study

Delaude

Demonceau²,

Noels³

2006

COC

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New imidazolium and imidazolinium salts were synthesized and their ability to act as stable N-heterocyclic carbene (NHC) ligand precursors was investigated in various ruthenium-catalyzed processes. Thus, 1,3diarylimidazol(in)ium chlorides bearing the phenyl, 1-naphthyl, 4-biphenyl, 3,5-dimethylphenyl, 2-tolyl, 2,6dimethylphenyl, 2,4,6-trimethylphenyl (mesityl), and 2,6-diisopropylphenyl substituents were prepared. They were combined with the [RuCl 2 (p-cymene)] 2 dimer and potassium tert-butoxide or sodium hydride to generate the corresponding ruthenium-arene complexes [RuCl 2 (p-cymene)(NHC)] in situ. The catalytic activity of all these species was investigated in the photoinduced ring-opening metathesis polymerization (ROMP) of norbornene and cyclooctene. Results from this study showed that the C4-C5 double bond in the imidazole ring of the NHC ligands was not crucial to achieve high catalytic efficiencies. The presence or the absence of alkyl groups on the ortho positions of the phenyl rings had a more pronounced influence. Blocking all the ortho positions was a requisite for obtaining efficient catalysts. Failure to do so probably resulted in the ortho-metallation of the carbene ligand, thereby altering the coordination sphere of the ruthenium active centers. Catalytic screenings were also carried out with the various imidazol(in)ium salts to evaluate their ability at promoting the cyclopropanation of styrene and cyclooctene with ethyl diazoacetate. Under the experimental conditions adopted, the exact nature of the N,N'-diaryl groups had very little influence on the outcome of these reactions. The imidazolium salts were further probed as catalyst modifiers for the Atom Transfer Radical Addition (ATRA) of carbon tetrachloride to styrene. Some species displayed a dual activity and promoted both olefin metathesis and ATRA.

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Section: Synthesis Of New N-heterocyclic Carbene Precursorsmentioning

confidence: 99%

Synthesis and Application of New N-Heterocyclic Carbene Ruthenium Complexes in Catalysis: A Case Study

Delaude

Demonceau²,

Noels³

2006

COC

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“…We have also reported on the catalytic activity of ruthenium sulfophthalocyanine, with particular regard to the oxidation of chloro-organics [7,8] and alcohols, [9] and, more recently, of cyclohexanone, cyclohexanol or cyclohexane to adipic acid with hydrogen peroxide and mono-persulfate. [10] During these studies, we become aware that, contrary to common belief, the metallophthalocyanine core does not possess an intrinsic chemical stability in oxidizing media, even under very mild conditions.…”

Section: Introductionmentioning

confidence: 99%

Rapid and Selective Oxidation of Metallosulfophthalocyanines Prior to Their Usefulness as Precatalysts in Oxidation Reactions

et al. 2003

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Two metallosulfophthalocyanines, RuPcS and FePcS, used in many catalytic oxidation reactions, were readily oxidized by hydrogen peroxide or monopersulfate, under acidic or neutral conditions in water, to form novel metal complexes derived from the facile oxidation of the PcS ring. Meso-nitrogen-oxide derivatives and metal-biliverdin-like derivatives were identified among the products at early reaction times, whereas at longer times fragmentation of the phthalocyanine ring occurred, with formation of sulfophthalimide and metal complexes containing the resulting tridentate ligand. The oxidative degradation of the MPcS complexes has been investigated by ESI-MS, UV/Vis-NIR and 1 H, 13 C and 15 N NMR

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“…Many recent publications focused on soluble metal phthalocyanines (MPc) because of their ability to catalyze a variety of oxidation reactions employing green oxidants like molecular oxygen or hydrogen peroxide [1,4]. This behavior can be related to the "metal centered 18 π electron aromatic system", that mimics the well known porphyrin system, with the only difference being that the four CH moieties in the meso positions have been replaced by four nitrogen atoms.…”

Section: Introductionmentioning

confidence: 99%

“…The MPc complexes can be derivatized with both hydrocarbon tails, to make them soluble in organic media, or polar groups, to enhance their solubility in polar media, among them sulfonic groups, which make possible their solubilization in water. Recently, we synthesized a water soluble sulfonated RuPcS complex, which was used, with other MPcS complexes (M = Fe, Co) in the catalytic oxidation of chlorophenols [4], chloroalkenes [6], alcohols [7], hydrocarbons [8] and polycyclic aromatic sulfur hydrocarbons [9], with hydrogen peroxide or potassium monopersulfate as oxidant.…”

Section: Introductionmentioning

confidence: 99%

Fate of nickel and cobalt sulfophthalocyanines under oxidizing conditions: a spectroscopic investigation

d’Alessandro

Tonucci

Dragani

et al. 2003

J. Porphyrins Phthalocyanines

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Two water-soluble metal sulfophthalocyanines, namely Ni(II)PcS and Co(II)PcS, were structurally characterized by electrospray ionization mass spectrometry (ESI-MS) and UV-vis and NMR spectroscopy. The dominant ion in ESI-MS was a penta-protonated monomeric Ni(II) complex and a tetra-protonated form with the Co(II) ion being oxidized to Co(III), confirming the facile oxidation of the central cobalt atom of the phthalocyanine ring by a soft ionization method as ESI. Experiments at various ESI voltages were also performed to ascertain the target of the oxidation, whether it was the metal or the phthalocyanine unsaturated system. Addition of small amounts of oxidizing agents, like potassium persulfate, resulted in a definite attenuation of the Q band in the UV-vis spectra, while ESI-MS detected a variety of complexes, containing at least one oxygen atom, which rapidly replaced the initial complexes.

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Ruthenium-catalyzed oxidative dehalogenation of organics

Cited by 40 publications

References 39 publications

Synthesis and Application of New N-Heterocyclic Carbene Ruthenium Complexes in Catalysis: A Case Study

Synthesis and Application of New N-Heterocyclic Carbene Ruthenium Complexes in Catalysis: A Case Study

Rapid and Selective Oxidation of Metallosulfophthalocyanines Prior to Their Usefulness as Precatalysts in Oxidation Reactions

Fate of nickel and cobalt sulfophthalocyanines under oxidizing conditions: a spectroscopic investigation

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