- Roles of supports on reducibility and activities of Cu3P catalysts for deoxygenation of oleic acid: In situ XRD and XAS studies
-
This work demonstrates for the first time that SiO2 and ultra-stable zeolite Y (USY) supports play significant roles in the reducibility of Cu2P2O7 to form Cu3P, which consequently affects the selectivity of oleic acid deoxygenation. The formation of supported Cu3P nanoparticles during hydrogen reduction of Cu2P2O7 was carefully investigated by in situ X-ray diffraction (in situ XRD), and in situ X-ray absorption spectroscopy (in situ XAS). The results indicate that the transformation of Cu2P2O7 to Cu3P occurs through several steps. In the first step, all supported Cu2P2O7 precursors are reduced to metallic Cu. Then, copper particles on SiO2 support react with phosphorus compounds and directly transform to Cu3P. On the other hand, copper particles on USY support partially transform to CuP2 and Cu(OH)2 before all converting to Cu3P. Despite multi-step transformations, Cu2P2O7/USY exhibits the lowest onset reduction temperature and provides Cu3P with a small particle size. The deoxygenation of oleic acid over Cu3P supported catalysts reaches nearly 100 % conversion. Both catalysts favor cyclization and aromatization to form cyclic and aromatic compounds. Cu3P/SiO2 achieves higher dodecylbenzene yield (46 %) than Cu3P/USY (33 %). A proposed mechanism consists of hydrogenation of oleic acid and deoxygenation, then followed by cracking, cyclization, aromatization, and alkyl rearrangement.
- Kochaputi, Nopparuj,Khemthong, Pongtanawat,Kasamechonchung, Panita,Butburee, Teera,Limphirat, Wanwisa,Poo-arporn, Yingyot,Kuboon, Sanchai,Faungnawakij, Kajornsak,Kongmark, Chanapa
-
-
Read Online
- Durability enhanced ionic liquid catalyst for Friedel-Crafts reaction between benzene and 1-dodecene: Insight into catalyst deactivation
-
Friedel-Crafts alkylation of benzene with 1-dodecene, which is an important reaction of synthetic detergent, was studied using the catalyst [bmim][TFSI]/AlCl3 (1-butyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide/AlCl3). These ionic liquid catalysts show biphasic behaviors at a specific condition. Active site species and Lewis acidity were determined by NMR and acetonitrile probe FT-IR. NMR spectroscopy investigations indicated that coordinated and uncoordinated [TFSI]- existed in the ionic liquid catalyst system simultaneously, while tetrahedral 4-coordinate Al2Cl7- was the main active species for Friedel-Crafts alkylation. The complex [AlClx(TFSI)y]- tends to decompose and release 4-coordinated Al2Cl7- and [TFSI]-. The phase behavior study of the ionic liquid [bmim][TFSI]/AlCl3 demonstrated that the upper phase could be used as an efficient heterogeneous catalyst when AlCl3/IL ≥ 1.5. Due to the presence of the anion [TFSI]- around the active sites, especially [TFSI]- at the uncoordinated state, the ionic liquid formed a stable and hydrophobic chemical environment, which enhanced catalyst durability. The influence of various reaction conditions including catalyst reusability on the alkylation reaction was studied, and the potential reasons for catalyst deactivation were discussed. The highest 2-LAB selectivity was more than 50% when 1-dodecene conversion was nearly 100%. Compared with liquid or solid acid catalyst, ionic liquid catalysts have many advantages concerning energy and the environment.
- He, Yibo,Wan, Chao,Zhang, Qinghua,Zhan, Xiaoli,Cheng, Dang-Guo,Chen, Fengqiu
-
-
Read Online
- Borane evolution and its application to organic synthesis using the phase-vanishing method
-
Although borane is a useful reagent, it is difficult to handle. In this study, borane was generated in situ from NaBH4 or nBu4NBH4 with several oxidants using a phase-vanishing (PV) method. The borane generated was directly reacted with alkenes, affording the desired alcohols in good yields after oxidation with H2O2 under basic conditions. The selective reduction of carboxylic acids with the evolved borane was examined. The organoboranes generated by the PV method successfully underwent Suzuki–Miyaura coupling. Using this PV system, reactions with borane can be carried out easily and safely in a common test tube.
- Soga, Nene,Yoshiki, Tomo,Sato, Aoi,Kawamoto, Takuji,Ryu, Ilhyong,Matsubara, Hiroshi
-
-
- Dumbbell-Shaped 2,2’-Bipyridines: Controlled Metal Monochelation and Application to Ni-Catalyzed Cross-Couplings
-
2,2’-Bipyridine ligands (dsbpys) with dumbbell-like shapes and differently substituted triarylmethyl groups at the C5 and C5’ positions showed high ligand performance in the Ni-catalyzed cross-electrophile coupling and the Ni/photoredox-synergistically catalyzed decarboxylative coupling reactions. The superior ligand effects of dsbpys compared to the conventional bpy ligands were attributed to the monochelating nature of dsbpys.
- Kim, Yongjoon,Iwai, Tomohiro,Fujii, Sho,Ueno, Kosei,Sawamura, Masaya
-
supporting information
p. 2289 - 2293
(2020/12/07)
-
- Iron-catalysed allylation-hydrogenation sequences as masked alkyl-alkyl cross-couplings
-
An iron-catalysed allylation of organomagnesium reagents (alkyl, aryl) with simple allyl acetates proceeds under mild conditions (Fe(OAc)2 or Fe(acac)2, Et2O, r.t.) to furnish various alkene and styrene derivatives. Mechanistic studies indicate the operation of a homotopic catalyst. The sequential combination of such iron-catalysed allylation with an iron-catalysed hydrogenation results in overall C(sp3)-C(sp3)-bond formation that constitutes an attractive alternative to challenging direct cross-coupling protocols with alkyl halides.
- Bernauer, Josef,Wu, Guojiao,Von Wangelin, Axel
-
p. 31217 - 31223
(2019/10/19)
-
- A process for preparing long-chain alkyl benzene (by machine translation)
-
The invention discloses a process for preparing long-chain alkyl benzene, including: the [...] chain alkyl agent in the metal compound assistants and the presence of the ionic liquid catalyst for carrying out the alkylation reaction, containing the reaction product of the long-chain alkyl benzene; wherein the alkylating agent is C states the long chain10 - C18 Straight-chain olefin or halide; said ionic liquid catalyst comprises a cation and anion, the cation is selected from the isoquinoline kind of positive ion, quinoline kind of positive ion and benzimidazole in at least one of the kind of positive ion, the anion is selected from sulfuric acid hydrogen radical, trifluoromethanesulfonic acid radical, the dihydrogen phosphates, paratoluene sulfonic acid, trifluoroacetic acid radical, four fluorophosphoric acid radical and six fluoboric acid in the root of the at least one. The method of the invention the kind of positive ion cation is isoquinoline, quinoline kind of positive ion or benzimidazole kind of positive ion of the ionic liquid as catalyst, to mix with the additive for preparing long-chain alkylbenzene, mild reaction conditions, the reaction conversion rate of raw materials is high, the product has good choice. (by machine translation)
- -
-
Paragraph 0080-0088; 0098-0101
(2019/05/16)
-
- METHOD OF REPROCESSING ALKANESULFONIC ACID
-
The invention relates to a method of reprocessing alkanesulfonic acid employed in a chemical process as an agent, catalyst or solvent and comprising the steps of: (a) removing an alkanesulfonic acid-comprising stream from a reaction mixture generated in the chemical process,(b) feeding the alkanesulfonic acid-comprising stream into a melt crystallization as the starting melt to form crystals of the alkanesulfonic acid, of hydrates of the alkanesulfonic acid or of a mixture of both suspended in mother liquor,(c) performing a solid-liquid separation to remove the crystals from the mother liquor,(d) optionally washing the crystals to remove mother liquor adhering to the crystals,(e) recycling the washed or unwashed crystals removed from the mother liquor into the chemical process.
- -
-
Paragraph 0129
(2018/12/04)
-
- Alkyl diphenyl phosphine and preparing alkyl diphenyl phosphine payment proportional to production alkyl benzene
-
The invention discloses alkyl diphenylphosphine and a method for preparing alkyl diphenylphosphine with co-production of alkylbenzene. The structural formula of alkyl diphenylphosphine is shown in a formula I. The method comprises: adding triphenylphosphine and metal lithium into an organic solvent for reaction for 3-6 hours at room temperature; and cooling the reaction system to 0-10 DEG C, adding halogenated straight-chain alkane for insulating reaction, then raising the temperature of the system to 30-80 DEG C, keeping the temperature to react for 1-3 hours, removing the organic solvent and reducing the pressure and distilling to separately obtain alkyl diphenylphosphine and alkylbenzene. According to the alkyl diphenylphosphine disclosed by the invention, alkyl is directly bonded with P, so that the alkyl diphenylphosphine can be dissolved in most solvents and can be used as a ligand for homogeneous catalysts. By virtue of the method disclosed by the invention, high value straight-chain alkylbenzene is co-produced while straight-chain alkyl diphenylphosphine is prepared by way of a one-pot process. Use of chloro-tert-butane which is relatively high in price and waste of the metal lithium are avoided. The method is simple to operate, efficient, low in energy consumption, low in cost and suitable for large-scaled industrial production.
- -
-
Paragraph 0074; 0078-0081
(2017/08/25)
-
- Metathesis of renewable polyene feedstocks – Indirect evidences of the formation of catalytically active ruthenium allylidene species
-
Cross-metathesis (CM) of conjugated polyenes, such as 1,6-diphenyl-1,3,5-hexatriene (1) and α-eleostearic acid methyl ester (2) with several olefins, including 1-hexene, dimethyl maleate and cis-stilbene as model compounds has been carried out using (1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene)-dichloro(o-isopropoxyphenylmethylene)ruthenium (Hoveyda-Grubbs 2nd generation, HG2) catalyst. The feasibility of these reactions is demonstrated by the observed high conversions and reasonable yields. Thus, regardless of the relatively low electron density, =CH–CH= conjugated units of molecules, including compound 2 as a sustainable, non-foodstuff source, can be utilized as building blocks for the synthesis of various value-added chemicals via olefin metathesis. DFT-studies and the product spectrum of the self-metathesis of 1,6-diphenyl-1,3,5-hexatriene suggest that a Ru η1-allylidene complex is the active species in the reaction.
- Kovács, Ervin,Sághy, Péter,Turczel, Gábor,Tóth, Imre,Lendvay, Gy?rgy,Domján, Attila,Anastas, Paul T.,Tuba, Róbert
-
supporting information
p. 213 - 217
(2017/09/12)
-
- Copper-catalyzed cross-coupling reactions of non-activated primary, secondary or tertiary alkyl chlorides with phenylmagnesium bromide
-
Efficient copper-catalyzed cross-coupling reactions of non-activated alkyl chlorides, including primary, secondary, and tertiary alkyl chlorides, with phenyl Grignard reagents were achieved. Preparation of phenylmagnesium bromide in 2-methyltetrahydrofuran is critical for the success of the reaction. This protocol expands the synthetic toolbox for the construction of C[sbnd]C bonds of non-activated primary, secondary, and tertiary alkyl chlorides via copper-catalyzed cross-coupling.
- Tao, Chuanzhou,Sun, Lei,Wang, Bin,Liu, Zhou,Zhai, Yadong,Zhang, Xiulian,Shi, Dahua,Liu, Weiwei
-
supporting information
p. 305 - 308
(2017/01/03)
-
- A Structure–Activity Study of Nickel NNN Pincer Complexes for Alkyl-Alkyl Kumada and Suzuki–Miyaura Coupling Reactions
-
A new series of Ni NNN pincer complexes were synthesized and characterized. The main difference among these complexes is the substituents on the side arm amino group(s). No major structural difference was found except for the C–N–C angle of the various substituents and the ‘pseudo bite angle’ of the complexes. Four new complexes were efficient for the alkyl-alkyl Kumada reaction of primary alkyl halides, and among them, one complex was also efficient with secondary alkyl halides. The influence of the substituents on the catalytic performance of the Ni complexes in alkyl-alkyl Kumada and Suzuki–Miyaura cross-coupling reactions was systematically investigated. No correlation was found between the catalytic activity and the key structural parameters (C–N–C angle and ‘pseudo bite angle’), redox properties or Lewis acidity of the complexes.
- Di Franco, Thomas,Stojanovic, Marko,Keller, Sébastien Carlos,Scopelliti, Rosario,Hu, Xile
-
p. 830 - 847
(2016/11/11)
-
- MnO2/TBHP: A Versatile and User-Friendly Combination of Reagents for the Oxidation of Allylic and Benzylic Methylene Functional Groups
-
In the presence of activated MnO2, tert-butyl hydroperoxide (TBHP) in CH2Cl2 is able to oxidize the allylic and benzylic methylene groups of different classes of compounds. I describe a one-pot oxidation protocol based on two sequential steps. In the first step, carried out at low temperature, MnO2 catalyses the oxidation of the methylene group. This is followed by a second step where reaction temperature is increased, allowing MnO2 both to catalyse the decomposition of unreacted TBHP and to oxidize allylic alcohols that could possibly be formed. The proposed oxidation procedure is generally applicable, although its efficiency, regioselectivity, and chemoselectivity are strongly dependent on the structure of the substrate. A simple and user-friendly synthetic procedure for the oxidation of allylic and benzylic methylene groups to the corresponding conjugated carbonyl derivatives is described. The proposed oxidation protocol is based on the combined use of MnO2 and tert-butyl hydroperoxide, and is generally applicable.
- Serra, Stefano
-
supporting information
p. 6472 - 6478
(2015/10/19)
-
- SINGLE-STEP PROCESS FOR PRODUCTION OF BRANCHED, CYCLIC, AROMATIC, AND CRACKED HYDROCARBONS FROM FATTY ACIDS
-
A catalytic process is provided which produces in a single reaction branched, cyclic and aromatic hydrocarbons, or cracked straight-chain hydrocarbons, from fatty acids in which the fatty acids are reacted over a multifunctional catalyst and undergo both decarboxylation and either conversion or cracking to form reaction products useful as fuels and for other applications that require a source of energy, or as feedstock for hydrocarbon-based commercial products such as surfactants, solvents and lubricants.
- -
-
Page/Page column 21
(2015/04/15)
-
- Decarboxylation and further transformation of oleic acid over bifunctional, Pt/SAPO-11 catalyst and Pt/chloride Al2O3 catalysts
-
Catalytic decarboxylation and further conversion of oleic acid to branched and aromatic hydrocarbons in a single process step, over Pt-SAPO-11 and Pt/chloride Al2O3 is presented. An increase of both reaction time and temperature increase the selectivity to heptadecane. Higher selectivity to heptadecane was observed in the presence of hydrogen. Decarboxylation of oleic acid was as high as ～98 wt% (selectivity for heptadecane >30%) at 325 C in the presence of hydrogen. Branched isomers, alkyl aromatics, like dodecyl benzene and cracked (17) paraffins were the other products.
- Ahmadi, Masoudeh,Macias, Eugenia E.,Jasinski, Jacek B.,Ratnasamy, Paul,Carreon, Moises A.
-
-
- Suzuki-miyaura cross-coupling reactions of unactivated alkyl halides catalyzed by a nickel pincer complex
-
A nickel(II) pincer complex, [(MeN2N)Ni-Cl], was used to catalyze alkyl-alkyl and alkyl-aryl Suzuki-Miyaura coupling reactions of unactivated alkyl halides. The coupling of 9-alkyl-9-borabicyclo[3.3.1]nonane and 9-phenyl-9-borabicyclo[3.3.1]nonane reagents with alkyl halides was achieved in modest to good yields. The reactions tolerated a variety of useful functional groups including ester, ether, furan, thioether, acetal, and Boc groups. Georg Thieme Verlag Stuttgart, New York.
- Di Franco, Thomas,Boutin, Nicolas,Hu, Xile
-
p. 2949 - 2958
(2013/11/06)
-
- Catalytic applications of OSDA-free Beta zeolite
-
Beta zeolite obtained from seeded synthesis without the use of organic structure directing agents (OSDAs) has been used as a catalyst in different types of reactions. The large number of strong acid sites resulted in a high activity for the alkylation of benzene with ethene and a high cracking activity in the hydroconversion of n-decane. However, the high framework polarity resulted in fast deactivation in the acylation of aromatic ethers. Dealumination treatments resulted in improved stability in alkylation reactions with the more reactive olefins like propene. In acylation reactions, the activity was significantly increased, and in hydroconversion, a better balance between the hydrogenation/dehydrogenation and the acid sites was obtained.
- De Baerdemaeker, Trees,Yilmaz, Bilge,Mueller, Ulrich,Feyen, Mathias,Xiao, Feng-Shou,Zhang, Weiping,Tatsumi, Takashi,Gies, Hermann,Bao, Xinhe,De Vos, Dirk
-
-
- Synthesis, insecticidal evaluation of novel 1,3,4-thiadiazole chrysanthemamide derivatives formed by an EDCI/HOBt condensation
-
A series of novel pesticides with two components derived from a 1,3,4-thiadiazole and chrysanthemic acid were synthesised via an EDCI/HOBt condensation. These 1,3,4-thiadiazole chrysanthemamides were identified by IR, 1H NMR and elemental analyses. Their insecticidal activity was also evaluated.
- Yu, Peng,Hu, Jun,Zhou, Tao-Yu,Wang, Peng,Xu, Yan-Hua
-
p. 703 - 706
(2012/03/10)
-
- Iron(II) complexes with functionalized amine-pyrazolyl tripodal ligands in the cross-coupling of aryl Grignard with alkyl halides
-
Structurally distinctive Fe(ii) complexes with furan, thiophene and pyridine functionalized amine-pyrazolyl tripodal hybrid ligands have been synthesized and crystallographically characterized. The tether substituent at the central amine plays an active role in determining the coordination mode of the ligand and the metal geometry. All complexes are catalytically active towards cross-coupling of aryl Grignard reagents with primary and secondary alkyl halides with β-hydrogen under ambient conditions. ESI-MS spectra analysis revealed the ligand-stabilised Fe(ii) and Mg(ii) species. The Royal Society of Chemistry 2011.
- Xue, Fei,Zhao, Jin,Hor, T. S. Andy
-
experimental part
p. 8935 - 8940
(2011/10/19)
-
- Copper-catalyzed cross-coupling reaction of organoboron compounds with primary alkyl halides and pseudohalides
-
Non-activated alkyl electrophiles, including alkyl iodides, bromides, tosylates, mesylates, and even chlorides, underwent copper-catalyzed cross-coupling with aryl boron compounds and alkyl 9-BBN reagents (see scheme; 9-BBN=9-borabicyclo[3.3.1]nonane). The reactions proceed with practically useful reactivities and thus complement palladium- and nickel-catalyzed Suzuki-Miyaura coupling reactions of alkyl halides.
- Yang, Chu-Ting,Zhang, Zhen-Qi,Liu, Yu-Chen,Liu, Lei
-
p. 3904 - 3907
(2011/05/15)
-
- Practical syntheses of sphingosine-1-phosphate and analogues
-
Sphingosine-1-phosphate (S1P, 1) is a bioactive sphin- golipid metabolite involved in a variety of critical cellular processes including proliferation, survival, and migration. For this reason the stereoselective syntheses of S1P and analogues are of great interest. Based on L-serine as source of chirality we achieved practical routes to prepare S1P (1) and the aryl group containing analogues 3 and 4 in fair amounts. The crucial stages of the syntheses are: introduction of the required side chain by addition of appropriate organometal- lics to Garner's aldehyde and conversion of the primary alcohols into the corresponding phosphates. Georg Thieme Verlag Stuttgart.
- Blot, Virginie,Jacquemard, Ulrich,Reissig, Hans-Ulrich,Kleuser, Burkhard
-
experimental part
p. 759 - 766
(2009/07/19)
-
- Liquid-crystalline polymorphism of symmetrical azobananas: Bis(4-(4-alkylphenyl)azophenyl) 2-nitroisophtalates
-
In this paper we present a series of novel compounds, bis(4-(4-alkylphenyl) azophenyl) 2-nitroisophtalates, which exhibit nematic and banana-type liquidcrystalline phases. The alkyl chain length varies from 1 to 18 carbons. The first ten members of this series exhibit nematic phase. The last eleven compounds exhibit banana-type liquid crystalline phases. The propyl and pentyl derivatives have extra second type of banana mesophase. Copyright Taylor & Francis Group, LLC.
- Zygadlo,Dardas,Nowicka,Hofmann,Galewski
-
scheme or table
p. 283 - 291
(2011/08/02)
-
- Synthesis of Cp*CH2PPh2 and its use as a ligand for the nickel-catalysed cross-coupling reaction of alkyl halides with aryl Grignard reagents
-
A new ligand, Cp*CH2PPh2 (Cp* = 1,2,3,4,5-pentamethyl-2,4-cyclopentadienyl), was prepared, and was used as a ligand for nickel-catalysed cross-coupling reaction of alkyl halides with aryl Grignard reagents, which nickel-phosphine complexes had never made possible. The Royal Society of Chemistry.
- Uemura, Minoru,Yorimitsu, Hideki,Oshima, Koichiro
-
p. 4726 - 4728
(2007/10/03)
-
- Method for formulation of synthetic gas oils or additives for gas oil
-
The invention relates to a method for formulation of a synthetic gas oil or an additive for gas oil in which an alkyl-aromatic compound or a mixture of alkyl-aromatic compounds is selected based on at least one parameter that is selected from the group that consists of the number of cycles of the aromatic core, the number of alkyl chains that are grafted to the aromatic cycle, the length of the alkyl chain or chains, the position of the aromatic cycle or cycles on the alkyl chain or chains of said alkyl-aromatic compound or compounds such that the cetane number of the synthetic gas oil or the additive for gas oil is greater than 30. The invention also relates to a process for the production of alkyl-aromatic compounds for use as a gas oil or additive.
- -
-
Page/Page column 2
(2008/06/13)
-
- Phosphaadamantanes as ligands for palladium catalyzed cross-coupling chemistry: Library synthesis, characterization, and screening in the Suzuki coupling of alkyl halides and tosylates containing β-hydrogens with boronic acids and alkylboranes
-
A 15-member library of phosphaadamantane ligands has been prepared via P-arylation of 1,3,5,7-tetramethyl-2,4,8-trioxa-6-phosphaadamantane. Screening of this tertiary phosphine collection has allowed for the rapid determination of the most suitable ligand, specifically 1,3,5,7-tetramethyl-6-(2,4- dimethoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane, for facilitating Suzuki-type couplings of alkyl halides or tosylates containing β-hydrogens with either boronic acids or alkylboranes.
- Brenstrum, Tim,Gerristma, David A.,Adjabeng, George M.,Frampton, Christopher S.,Britten, James,Robertson, Alan J.,McNulty, James,Capretta, Alfredo
-
p. 7635 - 7639
(2007/10/03)
-
- Novel acidic ionic liquids catalytic systems for friedel-crafts alkylation of aromatic compounds with alkenes
-
Novel acidic ionic liquids catalytic systems are developed for the Friedel-Crafts alkylation of aromatic compounds with alkenes.
- Qiao, Kun,Yokoyama, Chiaki
-
p. 472 - 473
(2007/10/03)
-
- Room-temperature Hiyama cross-couplings of arylsilanes with alkyl bromides and iodides
-
The first method for achieving Hiyama couplings of unactivated alkyl bromides and iodides is reported. The desired carbon-carbon bond formation proceeds under mild conditions (room temperature) with good functional-group tolerance. Copyright
- Lee, Jae-Young,Fu, Gregory C.
-
p. 5616 - 5617
(2007/10/03)
-
- Discotic liquid crystals of transition metal complexes, 31: Establishment of mesomorphism and thermochromism of bis[1,2-bis(4-n-alkoxyphenyl)ethane-1,2-dithiolene]nickel complexes
-
Two series of bis[1,2-bis(4-n-alkylphenyl)ethane-1,2-dithiolene]nickel, Cn-Ni (n= 1-12), and bis[1,2-bis(4-n-alkoxyphenyl)ethane-1,2-dithiolene]nickel, CnO-Ni(n = 1-12, 14, 16, 18), have been synthesized. Their mesomorphism, thermochromism, supramolecular structures and π-acceptor property have been investigated by using different scanning calorimetry, polarizing microscopy, temperature-dependent X-ray diffraction technique, electronic spectroscopy and cyclic voltammetry. From the X-ray diffraction and electronic spectral results, it was established that the CnO-Ni complexes for n ≤ 10 exhibit two differently colored discotic lamellar (DL) mesophases whereas none of the Cn-Ni complexes has a mesophase, and that the thermochromism (brown→green) is attributable to a slow transformation from the Ni-Ni bonded dimers to the Ni-S bonded dimers.
- Horie,Takagi,Hasebe,Ozawa,Ohta
-
p. 1063 - 1071
(2007/10/03)
-
- Organolithium addition to styrene and styrene derivatives: Scope and limitations
-
Styrene and a range of aryl-substituted styrene derivatives are shown to undergo efficient carbolithiation-trapping reactions in diethyl ether at -78 to -25 °C. The reactivities of different types of organolithium reagents were found to be: tertiary, secondary > primary; ? alkenyl, methyl, phenyl. Electron donating groups (e.g. methoxy and dialkylamino) at the ortho- or para- positions of the benzene ring deactivate the double bond towards organolithium addition, but their reactions with butyllithium can be facilitated by using TMEDA as co-solvent. 2-Benzyloxystyrene and 2-allyloxystyrene undergo efficient carbolithiation at -78 °C, but at room temperature alkyl transfer occurs, generating the corresponding alkylated phenol. 2-Vinylnaphthalene also undergoes carbolithiation-carboxylation in reasonable yield.
- Wei, Xudong,Johnson, Paul,Taylor, Richard J.K.
-
p. 1109 - 1116
(2007/10/03)
-
- Process for the in situ preparation of an ionic liquid
-
The invention relates to a process to prepare ionic liquids comprising a complex of metal halide and an ammonium halide. According to this process, a dry amine and a dry hydrohalic acid are reacted with a metal halide to form the desired ionic liquid. The process can be conducted at atmospheric pressure and at temperatures below 100°C, preferably in the presence of a heel of the same or another ionic liquid. The resulting ionic liquid can be used without further purification in conventional applications.
- -
-
-
- Enhanced selectivity in the preparation of linear alkylbenzenes using hexagonal mesoporous silica supported aluminium chloride
-
For decades sulphonated linear alkylbenzenes have been one of the worlds most important detergents. Industrially, their preparation involves the use of either aluminium chloride or hydrogen fluoride as catalysts in the alkylation stage of the reaction. The use of these catalysts presents severe problems in terms of both their environmental impact and their lack of selectivity towards the desired product. Solid acids, such as zeolites, can overcome these problems but at the expense of activity. It has now been discovered that by chemically supporting aluminium chloride on a MCM-41 type silica a reuseable catalyst is produced. It can be easily separated from the products and is environmentally benign. In addition, the new catalyst exhibits significant improvements in selectivity towards both the monoalkylated product and the preferred 2-phenyl isomer. Selectivity can be further increased by maximizing the relative activity of the catalytic sites situated within the pores of the catalyst.
- Price, Peter M.,Clark, James H.,Martin, Keith,Macquarrie, Duncan J.,Bastock, Tony W.
-
p. 221 - 225
(2013/09/08)
-
- Organolithium additions to styrene are synthetically viable
-
In diethyl ether at -78 to -25°C, styrene undergoes efficient addition reactions with a range of alkyllithium reagents, and the intermediate benzyllithiums can be trapped (e.g. with carbon dioxide and chlorotrimethylsilane); two aryl-substituted styrenes are shown to react in a similar manner.
- Wei, Xudong,Taylor, Richard J. K.
-
p. 187 - 188
(2007/10/03)
-
- Environmentally Friendly Catalysis using Supported Reagents: Evolution of a Highly Active Form of Immobilised Aluminium Chloride
-
An entirely heterogeneous form of aluminium chloride that is highly active in the liquid-phase alkylation of aromatics using alkenes and chloroalkanes is prepared by treating porous support materials with AlCl3 in solution.
- Clark, James H.,Martin, Keith,Teasdale, Andrew J.,Barlow, Simon J.
-
p. 2037 - 2040
(2007/10/02)
-
- LIGHT EMITTING LANGMUIR-BLODGETT FILMS
-
Langmuir-Blodgett films of europium tri-behenate, behenamido benzoate, 2-(4'-dodecylbenzoyl)benzoate-palmitate (1:1) mixture (EDBB/P) and 2-(4'-eicosoxybenzoyl)benzoate-arachidate (1:1) mixture were prepared and their UV absorption and photoluminescent properties were compared with solutions.Fluorescence intensities of LB films of EDBB/P were greatly enhanced by both effects of the large absorption of excitation light and the efficient energy transfer from organic to Eu(3+) ion.This enhancement is due to the preferable molecular alignment of LB films.
- Sugai, Kiyomi,Miyata, Seizo,Watanabe, Toshiyuki,Okamoto, Yoshiyuki
-
p. 271 - 276
(2007/10/02)
-
