- Inclusion of two push-pull N -methylpyridinium salts in anionic surfactant solutions: A comprehensive photophysical investigation
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Two N-methylpyridinium salts with push-pull properties have been investigated in the aqueous solution of anionic micelles of sodium dodecyl sulfate (SDS) and potassium p-(octyloxy)benzenesulfonate (pOoBSK) surfactants. These molecules are known to be extr
- Cesaretti, Alessio,Carlotti, Benedetta,Consiglio, Giuseppe,Del Giacco, Tiziana,Spalletti, Anna,Elisei, Fausto
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Read Online
- The Co-operative Effect in the Activation of the Phenoxide Anion with Oligo(oxyethylenes) containing Quaternary Ammonium Groups
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An unusual increase in activity accompanying the catalysis of a model substitution reaction between sodium phenoxide and 1-bromo-octane with oligo(oxyethylenes), linear or bound to the polymer, was observed after the introduction of quaternary ammonium gr
- Janout, Vaclav,Masar, Bohumil,Hrudkova, Hana,Cefelin, Pavel
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Read Online
- Biodegradable ionic liquids: Selected synthetic applications
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3-Methyl-1-(propyloxycarbonylmethyl)imidazolium octylsulfate 1a and 3-methyl-1-(pentyloxycarbonylmethyl)imidazolium octylsulfate 2a are ionic liquids that have previously been shown to be readily biodegradable in the CO2 headspace test (ISO 14593). In the present study, these ionic liquids were evaluated as reaction media for Diels?Alder and hydrogenation reactions. The comparison of the performance of these two designer solvents in these reactions with those conducted in other, non-biodegradable ionic liquids has demonstrated that they are comparable and viable solvents. CSIRO 2007.
- Bouquillon, Sandrine,Courant, Thomas,Dean, Darrell,Gathergood, Nicholas,Morrissey, Saibh,Pegot, Bruce,Scammells, Peter J.,Singer, Robert D.
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Read Online
- Methylation with Dimethyl Carbonate/Dimethyl Sulfide Mixtures: An Integrated Process without Addition of Acid/Base and Formation of Residual Salts
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Dimethyl sulfide, a major byproduct of the Kraft pulping process, was used as an inexpensive and sustainable catalyst/co-reagent (methyl donor) for various methylations with dimethyl carbonate (as both reagent and solvent), which afforded excellent yields of O-methylated phenols and benzoic acids, and mono-C-methylated arylacetonitriles. Furthermore, these products could be isolated using a remarkably straightforward workup and purification procedure, realized by dimethyl sulfide‘s neutral and distillable nature and the absence of residual salts. The likely mechanisms of these methylations were elucidated using experimental and theoretical methods, which revealed that the key step involves the generation of a highly reactive trimethylsulfonium methylcarbonate intermediate. The phenol methylation process represents a rare example of a Williamson-type reaction that occurs without the addition of a Br?nsted base.
- Chan, Bun,Lui, Matthew Y.,Lui, Yuen Wai
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- Mesoporous aromatic frameworks modified by metal chlorides in phenol alkylation with oct-1-ene
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Mesoporous polyaromatic frameworks (PAF) based on tetraphenylmethane were synthesized. The PAF/AlCl3 and PAF/FeCl3 catalysts were prepared by impregnating the synthesized products with aluminum and iron chlorides, respectively. The r
- Talanova, M. Yu.,Guojun,Karakhanov,Anisimov
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p. 2083 - 2087
(2020/01/21)
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- Base-Free Palladium-Catalyzed Borylation of Aryl Chlorides with Diborons
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The base-free palladium-catalyzed borylation of aryl chlorides with diborons was achieved. The base-free conditions offered acceptable functional group compatibility. Based on experimental and computational studies, it was shown that smooth boryl transfer from the diborons to the arylpalladium chloride was promoted by strong interaction between the Lewis acidic boron and the chlorine atom on palladium.
- Yamamoto, Yutaro,Matsubara, Hiroshi,Yorimitsu, Hideki,Osuka, Atsuhiro
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p. 2317 - 2320
(2016/07/28)
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- Copper and l-sodium ascorbate catalyzed hydroxylation and aryloxylation of aryl halides
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CuSO4·5H2O and NaAsc catalyzed hydroxylation and C-O/C-S cross-coupling reactions of aryl halides with phenols or 4-methylbenzenethiol were described. A wide range of substrates and test cases highlight the synthetic utility of the approach. A series of phenols, diaryl ethers, alkylaryl ethers, and diaryl thioethers were synthesized in high yield.
- Song, Guang-Lin,Zhang, Zhang,Da, Yu-Xia,Wang, Xi-Cun
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supporting information
p. 8823 - 8829
(2015/10/20)
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- Recyclable heterogeneous copper oxide on alumina catalyzed coupling of phenols and alcohols with aryl halides under ligand-free conditions
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An efficient alumina-supported CuO-catalyzed O-arylation of phenols and aliphatic alcohols with various aryl as well as heteroaryl halides under ligand-free conditions are reported. This protocol provides a variety of diaryl ether and bis-diaryl ether motifs by reacting different aryl/aliphatic halides with differently substituted phenols and saturated alcohols in the presence of a catalytic amount of CuO on alumina and KOH as a base at moderate temperature under nitrogen atmosphere. The described methodology is simple, straightforward and efficient to afford the cross-coupled products in high yields under ligand-free conditions. The explored catalyst is inexpensive, air-stable and recyclable up to three cycles.
- Swapna, Kokkirala,Murthy, Sabbavarapu Narayana,Jyothi, Mocharla Tarani,Nageswar, Yadavalli Venkata Durga
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supporting information; experimental part
p. 5978 - 5988
(2011/10/05)
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- Etherification of darylmethanols and 1-phenylalkan-1-ols over platinum on carbon
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In the presence of platinum on carbon (Pt/C), diarylmethanols and donor substituted 1-phenylalkan-1-ols undergo cross-etherification with primary and secondary alcohols.
- Thiemann, Thies
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experimental part
p. 515 - 525
(2010/04/23)
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- Synthesis and evaluation of alkoxy-phenylamides and alkoxy-phenylimidazoles as potent sphingosine-1-phosphate receptor subtype-1 agonists
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In the design of potent and selective sphingosine-1-phosphate receptor agonists, we were able to identify two series of molecules based on phenylamide and phenylimidazole analogs of FTY-720. Several designed molecules in these scaffolds have demonstrated selectivity for S1P receptor subtype 1 versus 3 and excellent in vivo activity in mouse. Two molecules PPI-4621 (4b) and PPI-4691 (10a), demonstrated dose responsive lymphopenia, when administered orally.
- Evindar, Ghotas,Bernier, Sylvie G.,Kavarana, Malcolm J.,Doyle, Elisabeth,Lorusso, Jeanine,Kelley, Michael S.,Halley, Keith,Hutchings, Amy,Wright, Albion D.,Saha, Ashis K.,Hannig, Gerhard,Morgan, Barry A.,Westlin, William F.
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scheme or table
p. 369 - 372
(2011/03/18)
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- Nickel-catalyzed cross-coupling of unactivated alkyl halides and tosylate carrying a functional group with alkyl and phenyl Grignard reagents
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By the use of catalytic amounts of a nickel salt and a 1,3-butadiene, primary and secondary alkyl Grignard reagents undergo cross-coupling with alkyl bromides, iodide, and tosylate carrying a functional group such as amide, ester, and ketone at 0 °C in THF. The present procedure provides a simple, convenient, and practical method for construction of carbon chains in the presence of various functional groups. PhMgBr also gave the corresponding coupling product in a moderate yield.
- Singh, Surya Prakash,Terao, Jun,Kambe, Nobuaki
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scheme or table
p. 5644 - 5646
(2011/02/25)
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- Conversion of a (sp3)C-F bond of alkyl fluorides to (sp 3)C-X (X = Cl, C, H, O, S, Se, Te, N) bonds using organoaluminium reagents
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A simple method for the conversion of (sp3)C-F bonds of alkyl fluorides to (sp3)C-X (X = Cl, C, H, O, S, Se, Te, N) bonds has been achieved by the use of a hexane solution of organoaluminum reagents having Al-X bonds. The Royal Society of Chemistry.
- Terao, Jun,Begum, Shameem Ara,Shinohara, Yoshiaki,Tomita, Masahiro,Naitoh, Yoshitaka,Kambe, Nobuaki
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p. 855 - 857
(2007/10/03)
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- Odorless benzenethiols in synthesis of thioglycosides and its application for glycosylation reactions
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p-Octyloxybenzenethiol (2) was synthesized as a new odorless benzenethiol. Moreover, preparation of thioglycosides using 2 and their application for glycosylation reactions were attempted. As a result, it was found that the thioglycosides were as excellen
- Kajimoto, Tetsuya,Ishioka, Yuichi,Katoh, Takahiro,Node, Manabu
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p. 5736 - 5739
(2007/10/03)
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- METHODS AND COMPOSITIONS FOR MODULATING SPHINGOSINE-1-PHOSPHATE (S1P) RECEPTOR ACTIVITY
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The present invention relates to compounds which modulate the activity of the SI P1 receptor, the use of these compounds for treating conditions associated with signaling through the S1 P1 receptor, and pharmaceutical compositions comprising these compounds.
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Page/Page column 59-60
(2010/10/20)
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- Silicon polypodands: Powerful metal cation complexing agents and solid-liquid phase-transfer catalysts of new generation
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Silicon polypodands 5-7 are found to be powerful complexing agents of alkali metal salts in low polarity solvents and very efficient catalysts in anion-promoted reactions under solid-liquid PTC conditions. The catalytic activity is comparable with that of the cyclic polyether PHDB18C6 8.
- Maia, Angelamaria,Landini, Dario,Leska, Boguslawa,Schroeder, Grzegorz
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p. 4149 - 4151
(2007/10/03)
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- Radical reaction by a combination of phosphinic acid and a base in aqueous media
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Treatment of various organic halides with phosphinic acid (hypophosphorous acid) in aqueous ethanol in the presence of a radical initiator and a base gave the corresponding reduced products in high yields. Addition of a base is indispensable for the reduction of halides by phosphinic acid. Allylic ether of o-iodophenol or 2-haloalkanal allylic acetal underwent radical cyclization under the same conditions to afford the corresponding cyclic product in excellent yield. Deuterated phosphinic acid was found to be an efficient chain carrier for the radical deuteration of organic halides. For example, a deuterium oxide solution of deuterated phosphinic acid, potassium carbonate, 2,2′-azobis(isobutyramidine) dihydrochloride as an initiator, and p-iodobenzoic acid was heated at reflux to give p-deuteriobenzoic acid in 94% yield. A mixed dioxane/D2O solvent system combined with DBU and potassium peroxodisulfate was crucial to deuterate hydrophobic substrates in high yields and with high deuterium incorporation. Complete deuterium incorporation was accomplished only by the reaction in D2O without an organic cosolvent and an organic base.
- Yorimitsu,Shinokubo,Oshima
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p. 225 - 235
(2007/10/03)
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- Quaternary ammonium salt-assisted organic reactions in water: Alkylation of phenols
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A series of quaternary ammonium salts has been tested as phase transfer agents to promote reactions between phenols and alkyl halides in an aqueous solution of sodium hydroxide in the absence of organic solvent. Methyltrioctylammonium chloride emerges as the most effective catalyst.
- Eynde,Mailleux
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- SYNTHESIS OF NEW CYCLOPHOSPHAZENIC POLYPODANDS WITH N,N-BISAMINE SUBUNITS AND THEIR COMPARISON, AS PHASE-TRANSFER CATALYSTS, WITH OTHER PODANDS
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Substituted cyclophosphazenes have been prepared by treatment of hexachlorocyclophosphazene with N,N-bisamines and employed as phase-transfer catalysts in anion-promoted reactions.New tridents have also been prepared.
- Corda, Luciana,Delogu, Giovanna,Maccioni, Antonio,Maccioni, Elias,Podda, Gianni
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p. 491 - 496
(2007/10/02)
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- Onium borates/borates of organometallic complexes and cationic initiation of polymerization therewith
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Novel onium borates of an element of Groups 15 to 17 of the Periodic Table, or borates of an organometallic complex of an element of Groups 4 to 10 of the Periodic Table, well suited for the photochemical/electron beam cationic initiation of polymerization/crosslinking, the anionic borate moiety of which having the formula: in which a and b are integers ranging from 0 to 4 and a+b=4; the symbols X are each a halogen atom when a ranges up to 3 and an OH functional group when a ranges up to 2; and the symbols R, which may be identical or different, are each a phenyl radical substituted by at least one element or electron-withdrawing substituent or by at least two halogen atoms, or an aryl radical containing at least two aromatic ring members, or such aryl radical bearing at least one electron-withdrawing substituent.
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- CYCLOPHOSPHAZENIC POLYPODANDS AS POWERFUL CATION COMPLEXING AGENTS, EFFICIENT PHASE-TRANSFER CATALYSTS AND ANION ACTIVATORS
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A survey dealing with cyclophosphazenic polypodands 3a-c, a new class of "octopus-like" molecules is reported.These many-armed ligands are powerful complexing agents of alkali metal salts and hence behave as very efficient catalysts in many reations (nucleophilic substitutions, eliminations, alkylations, oxidations, reductions) under solid-liquid and liquid-liquid phase-transfer catalysis conditions.Their catalytic activity is much better than that of the open-chain analogues PEGs 4, 5 and TRIDENT-1, 6.Moreover, anion activation realized by cyclophosphazenic polypodands, both of homogeneous and heterogeneous systems, is comparable with that obtained with the more sophisticated and expensive crown ethers.
- Landini, Dario,Maia, Angelamaria,Podda, Gianni
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p. 583 - 588
(2007/10/03)
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- POLYMER-SUPPORTED OLIGO(OXYETHYLENE)S, SULFOXIDES, AND CROWN ETHERS IN NUCLEOPHILIC SUBSTITUTION REACTIONS
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The efficiency of polymer analogues of oligo(oxyethylene)s and sulfoxides in the activation of nucleophilic substitution reactions were compared by testing to the reaction between sodium phenoxide and 1-bromooctane in 1,4-dioxane.With polymer analogues of crown ethers and polymer networks having the pseudo-crown ether structure the polymer effect can be achieved, i.e. a higher activation efficiency of the polymer analogue (in the L-S system) compared with the efficiency of the unimmobilized compound (in the homogeneous system).The results suggest that several molecules of the linear activator or of side active groupings (chains) on the polymer having the podand structure take part in the formation of the activation site (for the complex formation or solvation of the cation).
- Cefelin, Pavel,Hrudkova, Hana,Janout, Vaclav,Kalchenko, Vitalii I.,Valter, Bohumir
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p. 472 - 486
(2007/10/02)
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- Mechanism and Anion Activation in Solid-Liquid Phase-transfer Reactions Catalysed by Cyclophosphazenic Polypodands. Comparison with Cyclic Analogue Crown Ethers
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A kinetic study of the nucleophilic substitution of the methanesulfonic group by anions (Cl-, Br-, I-, SCN-, C6H5O-, C6H5CH2COO-) catalysed by cyclophosphazenic polypodands has been performed under solid-liquid phase-transfer conditions.The results obtained show that the mechanism of PTC previously found for cyclic ligands (crown ethers, cryptands) also operates in the case of these open-chain ligands: the attack by the anionic nucleophile on the substrate occurs in the organic phase and is rate determining of the overall process.The nucleophilicity scales found (I- > C6H5O- ca.SCN- > C6H5CH2COO-; I- > Br- > Cl-) as well as the anion activation are comparable with those found for cyclic crown ethers.This indicates that the anionic reactive species involved are similar in the complexes of both ligands.
- Landini, Dario,Maia, Angelamaria,Podda, Gianni,Secci, Daniela,Yan, Yong Ming
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p. 1721 - 1724
(2007/10/02)
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- SOLID PHASE COSOLVENTS: POLYMER ANALOGS OF N,N-DIALKYLAMIDES BASED ON POLYSTYRENE
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Polymers of styrene of various type can be readily amidomethylated by a reaction with N-(hydroxymethyl)amides.Analogs of N-methyl-2-pyrrolidone, N-methyl-6-hexanelactam, N-methyl-8-octanelactam and, N,N-dimethylacetamide were prepared by the polymeranalog
- Janout, Vaclav,Hrudkova, Hana,Valter, Bohumir,Cefelin, Pavel
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p. 1830 - 1838
(2007/10/02)
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- Triphenylsulfonium Salts as Effective Phase Transfer Catalysts under Alkaline Conditions
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Triphenylsulfonium salts work as effective phase transfer catalysts for nucleophilic substitution reactions on alkyl halides (e.g. 1) and addition reaction of dichlorocarbene to cyclohexene (8) under strongly alkaline conditions.
- Kondo, Shuji,Takeda, Yuji,Tsuda, Kazuichi
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p. 862 - 864
(2007/10/02)
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- SPECIFIC HYDRATION AND NUCLEOPHILIC REACTIVITY OF ORGANIC ANIONS UNDER PHASE-TRANSFER CATALYSIS AND HOMOGENEOUS CONDITIONS
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The effect of specific hydration on the nucleophilic reactivity of the organic anions 3a-i has been studied under PhCl-aqueous NaOH (15-50percent) PTC conditions and in anhydrous chlorobenzene.The sensitivity to the specific solvation, in the order oxanion > carbanion >/= nitranion >/= thianion, can be explained on the basis of the different donor atom tendency.The data provide a useful guide to the choice of the best reaction conditions of these anions under PTC.
- Landini, Dario,Maia, Angelamaria,Rampoldi, Alessandro
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p. 513 - 518
(2007/10/02)
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- W(CO)6 Mediated C-S Bond Cleavage Reactions
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W(CO)6-mediated reactions of thioethers in refluxing chlorobenzene yielded mainly the corresponding dimers.Optically active thioethers give the respective racemic products.Mercaptans, on the other hand, predominantly afford the corresponding reduced products.A deuterium labeling experiments suggest that the SH group is the hydrogen source in the latter reduction reactions.A free-radical mechanism is suggested.
- Ng, Chi Tat,Wang, Xiaojun,Luh, Tien-Yau
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p. 2536 - 2539
(2007/10/02)
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- The Effect of Two Terminal Alkoxy Groups on the Mesomorphic Properties of 4,4'-Disubstituted Phenylthiobenzoates
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A select variety of homologs of the dialkoxyphenylthiobenzoates were prepared.Their mesomorphic properties were determined by hot-stage polarizing microscopy and compared with those for the analogous RO-R' and R-OR' thioesters and esters.Unlike
- Neubert, Mary E.,Ziemnicka-Merchant, Barbara,Jirousek, Michael R.,Laskos, Stanley J.,Leonhardt, Darrin,Sharma, Ram B.
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p. 209 - 240
(2007/10/02)
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- Synthesis and Liquid Crystalline Properties of 1-(trans-4-Alkylcyclohexylethyl)-4-Alkyl- and -4-Alkoxy-Benzenes, Their Ketone Precursors, and Some Lateral Fluoro-Derivatives
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The preparation of some 1-(trans-4-alkylcyclohexylethyl)-4-alkyl- and -4-alkoxy-benzenes, their methylenecarbonyl linked analogues and their laterally fluoro- and bromo-substituted derivatives is reported.Twenty-four inter-related compounds have been prepared and the trends in their transition temperatures are discussed.Both the melting points and clearing points for these compounds are relatively low and, in general, SB and SA phases predominate.The suitability of these compounds as additives to SC materials has been assessed using two SC hosts.Keywords: Mesogenic cyclohexylethanes, mesogenic ketones, fuoro-substitution of mesogens
- Gray, George W.,Lacey, David,Scrowston, Richard M.,Shenouda, Ibrahim G.,Toyne, Kenneth J.
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p. 101 - 116
(2007/10/02)
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- Sulfonium Salts as Liquid-Liquid Phase-Transfer Catalysts
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Lauryldimethylsulfonium and tri(n-butyl)sulfonium salts serve as highly efficient catalysts for two-phase reactions.
- Kondo, Shuji,Takeda, Yuji,Tsuda, Kazuichi
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p. 403 - 404
(2007/10/02)
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- Ameliorations et simplification de la synthese des ethers phenoliques par alkylation d'ions phenates: catalyse par transfert de phase solide-liquide sans solvant
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Several aryl ethers can be obtained in excellent yields under mild and economical conditions in the absence of organic solvents by reacting stoechiometric amounts of corresponding phenol, finely ground KOH and alkyl bromides in the presence of 2percent Aliquat 336.This method is very favourable compared with recent works dealing with anionic activation.
- Loupy, Andre,Sansoulet, Jean,Zand, Farchid Vaziri-
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p. 1027 - 1035
(2007/10/02)
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- POLYMER SULFOXIDES BASED ON POLY(VINYL ALCOHOL) AS EFFECTIVE CATALYSTS OF NUCLEOPHILIC SUBSTITUTION REACTIONS
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Using the addition of alcohols to ethyl vinyl sulfoxide, a number of 2-alkoxyethyl ethyl sulfoxides were prepared, containing the following alkyls: methyl, ethyl, isopropyl, benzyl, and cyclohexyl.With a 10 mole percent excess of alcohol the extent of the reaction was 70-95percent.By a polymeranalogous reaction with poly(vinyl alcohol) and poly(ethylene-co-vinyl alcohol), copolymers poly and poly were prepared; the reaction with polymer alcohols requires the use of excess ethyl vinyl sulfoxide.These polymer sulfoxides were tested as catalysts of nucleophilic substitution reactions, using reactions of 1-bromooctane with sodium phenoxide, sodium iodide and potassium thiocyanate.They are more effective catalysts than polymer sulfoxides based on crosslinked poly(styrene) under the conditions of a two-phase (S-L) and three-phase (L-S-L) catalysis.
- Hrudkova, Hana,Cefelin, Pavel,Janout, Vaclav
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p. 2204 - 2211
(2007/10/02)
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- Synthesis and Liquid Crystalline Phases of Pyridazine Derivatives III
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Eight compounds with the general structure R-X-Y-O-R' were synthesizzed where X is a phenyl ring, Y is a 3,6 disubstituted pyridazine ring, R is a n-alkyl or n-alkoxy group and R' may be either a n-alkyl group or a branched alkyl group containing a chiral
- Liang, Jason C.,Cross, Julie O.
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- Tetrakis-sulphoxides: a New Type of Phase-transfer Catalyst for Nocleophilic Displacements and Alkylations
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Tetrakis(alkylsulphinylmethyl)methanes have been shown to serve as good phase-transfer catalysts which accelerate SN2 type displacements of octyl bromide with various nucleophiles (thiocyanate, cyanide, phenoxide, and thiolate) in solid-liquid two-phase systems.Alkylation of phenylacetonitrile with alkyl halides has also been carried out in liquid-liquid two-phase systems in the presence of the above sulphoxides to afford the corresponding mono-alkylated products in high yields.
- Fujihara, Hisashi,Imaoka, Koji,Furukawa, Naomichi,Oae, Shigeru
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p. 333 - 336
(2007/10/02)
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- SOLID-PHASE COSOLVENTS. A POLYMER ANALOG OF N-METHYL-2-PYRROLIDONE BASED ON CROSSLINKED POLYSTYRENE
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Polymer analogs of N-methyl-2-pyrrolidone were prepared by reacting crosslinked polystyrene with N-hydroxymethyl-2-pyrrolidone.These polymers are effective catalysts of nucleophilic substitution reactions carried out under liquid-solid (L-S) and liquid-solid-liquid conditions.
- Janout, Vaclav,Cefelin, Pavel
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p. 3525 - 3528
(2007/10/02)
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- Tris(polyoxaalkyl)amines (Trident), a New Class of Solid-Liquid Phase-Transfer Catalysts
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A new class of solid-liquid phase-transfer catalysts has been prepared.These tris(polyoxaalkyl)amines (I) are designed to obtain the best balance between straightforward synthesis (cheap starting materials), high activity, easy recovery, and low toxicity.The catalysts are synthesized from ethylene glycols by a simple one-step method in yields in the range of 65-81percent.They show high catalytic effects in aliphatic nucleophic substitutions and aromatic nucleophilic substitutions on activated and unactivated molecules.In the Ullman synthesis (a new PTC reaction) there is a synergic effect of anionic activation by tridents and by copper salts.Reactions have been carried out at temperatures up to 180 deg C without evidence of decomposition of the tris(polyoxaalkyl)amines. The behavior and catalytic activity of these catalysts are discussed.
- Soula, Gerard
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p. 3717 - 3721
(2007/10/02)
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- Sulphoxide Substituted Pyridines as Phase-transfer Catalysts for Nucleophilic Displacements and Alkylations
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2-Methylsulphinyl-, 2-methylsulphinylmethyl-, 2,6-bis(methylsulphinyl)-, 2,6-bis(methylsulphinylmethyl)-pyridines, bis(2-pyridylmethyl)sulphoxide, and 2-methylsulphinylpyridine N-oxide have been prepared.These sulphoxides served as good phase-transfer catalysts which accelerate SN2 type displacements of octyl bromide with various nucleophiles (thiolate, cyanide, thiocyanate, and phenoxide) in solid-liquid two-phase systems.Alkylations of phenylacetonitrile and benzyl methyl ketone with alkyl halides were also carried out in liquid-liquid two-phase systems in the presence of the above sulphoxides to afford the corresponding monoalkylated products in high yields.Pyridine derivatives bearing polysulphinyl groups were found to be even more effective catalysts for these two-phase alkylations.Neither 2-methylthio- nor 2-methylsulphonyl-pyridine catalysed SN2 type displacement reactions effectively.
- Furukawa, Naomichi,Ogawa, Satoshi,Kawai, Tsutomu,Oae, Shigeru
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p. 1833 - 1838
(2007/10/02)
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- Solvolysis of N-n-Alkylacridiniums in Phenol and Carboxylic Acids. Primary Carbonium Ions as Possible Intermediates
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N-n-Octyl (1a) and N-n-dodecylacridinium (1b) ions solvolyze in phenol to give mixtures of the n-alkyl phenyl ethers and all the isomeric secondary straight-chain o- and p-alkylphenols.Solvolyses of 1a in carboxylic acids give a mixture of 1-, 2-, 3-, and 4-octyl carboxylic esters.Structures are deduced by GC/MS.Mechanisms are discussed.
- Katritzky, Alan R.,El-Mowafy, Azzahra M.
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p. 3511 - 3517
(2007/10/02)
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- Gas-Liquid Phase-transfer Synthesis of Phenyl Ethers and Sulphides with Carbonate as Base and Carbowax as Catalyst
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When a mixture of a phenol (or thiol) and an alkyl halide is passed, in the gaseous state, through a solid bed of potassium carbonate (or sodium hydrogencarbonate) and catalytic amounts of Carbowax 6000, contained in a glass column at 170 deg C, the corresponding ethers (or sulphides) may be collected at the outlet.The Carbowax acts in a similar manner to the crown ethers used in solid-liquid phase-transfer catalysis.The potassium carbonate-Carbowax combination allows the generation of anions up to pKa of ca. 12.The catalysis mechanism is discussed and the synthesis of several ethers and thioethers is reported, some of which are obtained only with difficulty by normal liquid-liquid phase-transfer catalysis.
- Angeletti, Enrico,Tundo, Pietro,Venturello, Paolo
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p. 1137 - 1142
(2007/10/02)
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- ORGANIC SULFUR COMPOUNDS CONTAINING HETEROCYCLES. II: METHYL 2-PYRIDYL SULFOXIDE AS PHASE TRANSFER CATALYST.
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Methyl 2-pyridyl sulfoxide was found to be an excellent phase transfer catalyst which promotes simple SN2 type displacement reactions of alkyl halides with some nucleophiles.
- Furukawa, Naomichi,Kishimoto, Keiko,Ogawa, Satoshi,Kawai, Tsutomu,Fujihara, Hisashi,Oae, Shigeru
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p. 4409 - 4412
(2007/10/02)
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- TETRAKIS-SULFOXIDES AS PHASE TRANSFER CATALYSTS
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Tetrakis(alkyl-sulfinylmethyl)methanes serve as highly efficient phase transfer catalysts in SN2 type displacement reactions of n-octyl bromide with a few nucleophiles.
- Fujihara, Hisashi,Imaoka, Koji,Furukawa, Naomichi,Oae, Shigeru
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p. 1293 - 1296
(2007/10/02)
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- Phase Transfer Catalysts Based on Sucrose Ethyleneoxide Adducts
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Sucrose ethyleneoxide adducts have been prepared by reaction of sucrose with various amounts of ethyleneoxide in DMSO.The resulting polypode molecules were found to be efficient phase transfer catalysts in nucleophilic substitutions, oxidation and dichlorcarbene generation.Polymerisable polypodes have been obtained by reaction of sucrose ethyleneoxide adducts with methacrylic anhydride or methacryloylchloride in pyridine.Free radical polymerisation of the resulting mixtures of mono- and polyfunctional methacrylic esters of sucrose ethyleneoxide adducts yielded crosslinked gels.These polymer-supported "octopus-molecules" were found to be efficient triphase catalysts. - Keywords: Polypode ligand as phase transfer catalyst; Polypode ligand, polymer supported
- Gruber, Heinrich,Greber, Gerd
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p. 1063 - 1076
(2007/10/02)
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