A Cationic Surfactant as a Phase-Transfer Catalyst for Reactions in Liquid/Liquid and Solid/Liquid Systems. Its Use in the Manufacturing of Trichlorobenzene from Lindane Wastes and Vitamin A Production

Sirovski, Felix; Berlin, E.R.; Mulyashov, Sergei A.; Bobrova, Elena Aleksandrovna; Batrakova, and Zinaida I.; Dankovskaya, Dana F.

doi:10.1021/op960030f

Cited by 7 publications

(5 citation statements)

References 2 publications

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“…in a biphasic isooctane-aqueous KOH system, containing a heterogeneous catalyst (supported Pd, Pt, or Raney-Ni) and Aliquat 336, lindane may theoretically undergo two different dechlorination processes. Either base-assisted DHC, which is catalyzed by quaternary ammonium salts [9,10]; or catalytic HDC, also possible under these conditions in the presence of hydrogen. For this second process, as we have previously shown on the examples of polychlorinated aromatics [22][23][24][25][26], the presences of a base and of a quaternary salt are also necessary to achieve effective dechlorination.…”

Section: Base-assisted Dehydrochlorination Of Lindanementioning

confidence: 99%

“…As long ago as in 1871, Zinin reported on the reduction of HCH to benzene with metallic Zn in ethanol [6]. Lindane and its isomers can undergo the dehydrochlorination (DHC) reaction to form tricholorobenzenes (TCBs) either by thermal or the base-assisted processes [7][8][9][10]. The latter is more selective and can be carried out under mild conditions in the presence of a phase-transfer (PT) catalyst and an aqueous base [9,10].…”

Section: Introductionmentioning

confidence: 99%

“…Lindane and its isomers can undergo the dehydrochlorination (DHC) reaction to form tricholorobenzenes (TCBs) either by thermal or the base-assisted processes [7][8][9][10]. The latter is more selective and can be carried out under mild conditions in the presence of a phase-transfer (PT) catalyst and an aqueous base [9,10]. Electrochemical [11] and bacterial [11][12][13] processes of HCH or lindane degradation are known and afford benzene.…”

Section: Introductionmentioning

confidence: 99%

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Dechlorination of lindane in the multiphase catalytic reduction system with Pd/C, Pt/C and Raney-Ni

Zinovyev

Shinkova

Perosa

et al. 2004

Applied Catalysis B: Environmental

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Dechlorination of ␥-hexachlorocyclohexane (lindane) is carried out in the multiphase catalytic system, composed by isooctane and aqueous KOH phases, a phase transfer agent (Aliquat 336) and a metal catalyst, e.g. 5% Pd/C, 5% Pt/C, or Raney-Ni. At 50• C and atmospheric pressure the full conversion of lindane to 1,2,4-tricholorobenzene (1,2,4-TCB) is achieved in 5-10 min via the base assisted dehydrochlorination, followed by the metal catalyzed hydrodechlorination with hydrogen to benzene. Aqueous KOH and Aliquat 336 strongly affect the reaction: if present together they co-promote both dehydrochlorination and hydrodechlorination steps; if KOH is absent, the reaction is forced to follow a different catalytic pathway, which involves a removal of a pair of chlorines at every reaction step by zerovalent metal followed by reduction of metal with hydrogen. This is proven by the formation of 3,4,5,6-tetrachlorocyclohex-1-ene and 5,6-dichlorocyclohexa-1,3-diene as intermediates in the reaction over Raney-Ni, and by the absence of TCBs in the reactions on all the catalysts studied. The final yield of benzene via this pathway can be achieved in shorter times than in a system with KOH. The presence of Aliquat 336 in the isooctane-water system produces a 10-fold rate increase, the presence of alkaline water is also important since it avoids catalyst poisoning by neutralizing the hydrochloric acid formed.

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Section: Base-assisted Dehydrochlorination Of Lindanementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Dechlorination of lindane in the multiphase catalytic reduction system with Pd/C, Pt/C and Raney-Ni

Zinovyev

Shinkova

Perosa

et al. 2004

Applied Catalysis B: Environmental

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“…Despite having superannuated origins, the ubiquitous influence of detergents and micellar systems, in contemporary science is undeniable. The controlled concentration dependent self-assembly of these soft materials into larger sophisticated functional colloids of definite size and shape has found renewed interests largely due to the now wide range of their applications: as templates for the self-assembly of metal 1 and porous silica 2 nanoparticles, drug delivery systems, 3 phase transfer catalysts, 4 surfactant-stabilised foams, 5 lyotropic liquid crystal-based devices, 6 enhanced oil/hydrocarbon recovery agents, 7 as well as the non-covalent functionalisation and solubilisation of carbon nanotubes 8 and other nanoparticulates in water. In recent years colloid science has experienced a paradigm shift 9 in which the primary focus of amphiphile molecular design is no longer concerned with the efficiency and effectiveness of detergency but rather the incorporation of information rich structural motifs capable of imparting 10 external stimuli (e.g., chemical-, photo-, and electrochemical stimuli) responsive characteristics by which micellar selfassembly -and consequently detergency-can be controllably modulated.…”

Section: Introductionmentioning

confidence: 99%

Reversible morphological changes of assembled supramolecular amphiphiles triggered by pH-modulated host–guest interactions

et al. 2016

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Reversible template-directed micellar-size and shape modulation by virtue of host-guest reversible docking of molecular templates at the micellar-solvent interface was achieved in water. By combining a π-electron deficient bipyridinium-based gemini amphiphile which is capable of binding and aligning with a π-electron rich tri(ethylene glycol)-disubstituted 1,5-diaminonaphthalene, a switchable detergent system which operates through the pH-responsive formation of bisammonium dications was realised. The binding of the 1,5-diaminonaphthalene guest to the bipyridinium-based micellar aggregate superstructure can be actuated by the addition of acid and base. Upon the addition of acid, protonation of the guest forming the dication deactivates molecular recognition with the charged head groups of the micellar aggregate by Coulombic repulsion. This process is completely reversible upon the addition of base, whereby the guest reintercalates into the superstructure -again forming donor-acceptor π-π stacks at the micellar-solvent interface amongst contiguous surfactant head groups. Synchrotron small angle X-ray scattering and dynamic laser light scattering confirm that this form of reversible directionally-templated micellisation results in an oblate spheroid-to-lamellar micelle morphological transition with a stabilising net decrease in the free energy of micellisation of 1.4 kcal mol(-1) per hydrophobic tail.

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“…The usual catalysts (TEBA or Bu 4 NBr) do not work in diluted alkali. Therefore, we had to apply our usual long-chained catalyst PhCH 2 (Me) 2 N + (C 16 −C 18 )Cl - . The results are listed in Tables and .…”

Section: Introductionmentioning

confidence: 99%

Some Examples of Phase-Transfer Catalysis Application in Organochlorine Chemistry

Sirovski

1999

Org. Process Res. Dev.

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Kinetics of phase-transfer catalysed (PTC'd) dehydrochlorination of the r-isomer of hexachlorocyclohexane in the presence of proton donors was investigated. Carboxylic acids and picric acid act as inhibitors. Benzyl alcohol strongly promotes the reaction. The plots of observed rate constants vs phenol and pentachlorophenol concentration have a bell-shaped form that was not observed before. An example of long-chain quats application in the synthesis of the ketamine anaesthetic intermediate by dehydrochlorination in dilute alkali is shown. Another application of phase-transfer catalysis (PTC) in organochlorine chemistry is the aqueous (sodium hypochlorite) chlorination of alkyl aromatic compounds. The results of m-phenoxytoluene chlorination and reaction kinetics in the presence of the polymeric crown are described.

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A Cationic Surfactant as a Phase-Transfer Catalyst for Reactions in Liquid/Liquid and Solid/Liquid Systems. Its Use in the Manufacturing of Trichlorobenzene from Lindane Wastes and Vitamin A Production

Cited by 7 publications

References 2 publications

Dechlorination of lindane in the multiphase catalytic reduction system with Pd/C, Pt/C and Raney-Ni

Dechlorination of lindane in the multiphase catalytic reduction system with Pd/C, Pt/C and Raney-Ni

Reversible morphological changes of assembled supramolecular amphiphiles triggered by pH-modulated host–guest interactions

Some Examples of Phase-Transfer Catalysis Application in Organochlorine Chemistry

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