- Rational selection of the cation of an ionic liquid to control the reaction outcome of a substitution reaction
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A range of ionic liquids was examined as solvents for a substitution reaction. They were chosen through rationally varying the ionic liquid cation in order to enhance the rate constant. Access to charge and electron-withdrawing substituents benefitted rat
- Hawker, Rebecca R.,Haines, Ronald S.,Harper, Jason B.
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Read Online
- Anion-cation mediated structural rearrangement of an in-derived three-dimensional interpenetrated metal-organic framework
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Postsynthetic modification of metal-organic frameworks (MOFs) has proven an effective method of synthesizing architectures that have proven challenging to produce via classic solvothermal means. Herein we report the anion-cation assisted solid-state trans
- Bellas, Michael K.,Mihaly, Joseph J.,Zeller, Matthias,Genna, Douglas T.
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Read Online
- Understanding the effects of solvate ionic liquids as solvents on substitution processes
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The effects of solvate ionic liquids as solvents have been considered for two substitution processes where the solvent effects of typical ionic liquids have been extensively investigated previously; the bimolecular nucleophilic substitution (SN
- Schaffarczyk McHale, Karin S.,Wong, Michaela J.,Evans, Alicia K.,Gilbert, Alyssa,Haines, Ronald S.,Harper, Jason B.
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Read Online
- Crystal structures of binuclear Bi(III) chloride and bromide complexes with some cations — Alkylated pyridine derivatives
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By a reaction of [BiX6]3– with salts of various N-alkylated pyridine derivatives in 2M HX (X = Cl, Br), (N-BzPy)4[Bi2X10] complexes (X = Cl (1), Br (2), (4-MePyH)4[Bi2Cl10/
- Adonin,Gorokh,Samsonenko,Korol‘kov,Sokolov,Fedin
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Read Online
- Novel antimonate luminescent material Luminescent film and preparation method thereof
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The invention belongs to the technical field of functional materials, in particular to a novel antimonate bromide luminescent material. The benzyl substituted pyridinium pentabromide antimonate is a compound composed of antimony pentabromide anions and be
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Paragraph 0031-0033
(2021/06/21)
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- Targeted Synthesis of Trimeric Organic-Bromoplumbate Hybrids That Display Intrinsic, Highly Stokes-Shifted, Broadband Emission
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Zero-dimensional (0D) hybrid organic-inorganic lead halides have been shown to display efficient broadband photoluminescence and are, therefore, of significant interest for artificial lighting applications. However, work that investigates the formability of the materials as a function of templating organic cation structure is rare. This severely limits our ability to rationally design new materials displaying specific structural and photophysical properties. With the goal of accessing rare 0D trimeric bromoplumbates, we have systematically varied templating N-alkylpyridinium cations and examined their impact upon inorganic lattice structure. Whereas comparatively short and flexible N-alkyl substituents (ethyl, 2-hydroxyethyl, and pentyl) yield one-dimensional (1D) inorganic chains, more rigid substituents (benzyl, acetamidyl, and cyanomethyl) afford hybrids composed of lead bromide face-sharing trimers (i.e., [Pb3Br12]6-). Of the rigid substituents studied, benzyl groups were found to enforce the highest level of distortion of the [PbBr6]4- octahedra that comprise their trimeric structures. Upon exposure to ultraviolet (UV) light, N-benzylpyridinium lead bromide (1)6[Pb3Br12] exhibits a broadband emission, centered at 571 nm, which spans from 400 to 800 nm. More specifically, it displays a large Stokes shift of ca. 1.39 eV and a full width at half-maximum of ca. 146 nm. This broadband emission decays with a comparatively long lifetime of 426 ns at room temperature, which increases to 5.8 μs at 77 K. The reduced size and dimensionality of its inorganic lattice also result in a photoluminescence quantum yield (of at least 10%) that is approximately one order of magnitude higher than that of its 1D congeners. Mechanistically, broadband emission in (1)6[Pb3Br12] is believed to originate from triplet excited state(s) obtained from excited-state structural reorganization of the [Pb3Br12]6- moiety.
- Febriansyah, Benny,Neo, Chong Shern Daniel,Giovanni, David,Srivastava, Shivani,Lekina, Yulia,Koh, Teck Ming,Li, Yongxin,Shen, Ze Xiang,Asta, Mark,Sum, Tze Chien,Mathews, Nripan,England, Jason
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p. 4431 - 4441
(2020/07/03)
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- Are pyridinium ylides radicals?
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Pyridinium ylides are usually considered nucleophiles that can undergo various reactions involving electron pairs. However, it was found that ylides resulting from deprotonation ofN-alkyl-substituted pyridinium salts exhibit radical characters, with no di
- Liao, Fan,Huang, Wenhuan,Chen, Biao,Ding, Zijing,Li, Xingxing,Su, Hao,Wang, Tao,Wang, Yucai,Miao, Hui,Zhang, Xiaolong,Luo, Yi,Yang, Jinlong,Zhang, Guoqing
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supporting information
p. 11287 - 11290
(2020/10/06)
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- Enantiomerically enriched tetrahydropyridine allyl chlorides
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Enantiomerically enriched allyl halides are rare due to their configurational lability. Here we report stable piperidine-based allyl chloride enantiomers. These allyl chlorides can be producedviakinetic resolution, and undergo highly enantiospecific catal
- Brethomé, Alexandre V.,Fletcher, Stephen P.,Karabiyikoglu, Sedef,Palacin, Thomas,Paton, Robert S.
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p. 4125 - 4130
(2020/05/08)
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- ENANTIOMERIC COMPOUNDS
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The present invention relates to enantiomeric compounds, their use in stereospecific reactions and to a method of preparing enantiomeric compounds.
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Page/Page column 24
(2020/05/07)
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- The effect of bisimidazolium-based ionic liquids on a bimolecular substitution process. Are two head(group)s better than one?
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A homologous series of biscationic ionic liquids based on two imidazolium centres, separated by alkyl chains of varying length, were examined as solvents for a bimolecular substitution reaction across a range of proportions of ionic liquid in the reaction
- Haines, Ronald S.,Harper, Jason B.,Liu, Kenny T.-C.
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supporting information
p. 7388 - 7395
(2020/10/13)
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- Aggregation induced emission by pyridinium-pyridinium interactions
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Non-covalent intermolecular interactions between pyridinium subunits in a crystal-state are an efficient means to accomplish aggregation induced emission and avoid aggregation caused quenching.
- Leduskrasts, Kaspars,Suna, Edgars
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p. 460 - 465
(2019/01/16)
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- N-benzyl-tetrahydropyridine compound and preparation method thereof
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The invention provides an N-benzyl-tetrahydropyridine compound and a preparation method thereof, and the preparation method comprises the following steps: S1, adding benzyl bromide into a pyridine compound to carry out nucleophilic substitution reaction t
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Paragraph 0045-0050
(2019/06/30)
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- Efficient catalytic oxidation of methyl aromatic hydrocarbon with: N -alkyl pyridinium salts
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A series of N-alkyl pyridinium salts were synthesized and employed as metal-free catalyst for the selective oxidation of methyl aromatic hydrocarbon with molecular oxygen. The electronic effect of the substitutes was found to be an important factor for the catalytic performance. With the introduction of electron-donating substitute -N(CH3)2, the conversion of p-xylene and selectivity of p-toluic acid could be simultaneously increased. 1-Benzyl-4-N,N-dimethylaminopyridinium salt showed the highest catalytic activity, and 95% conversion with 84% of selectivity to p-toluic acid could be obtained for the selective oxidation of p-xylene. Several methyl aromatic hydrocarbons could all be efficiently oxidized with the reported catalyst at the absence of any metal species.
- Zhang, Qiaohong,He, Honghao,Wang, Huibin,Zhang, Zhan,Chen, Chen
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p. 38891 - 38896
(2019/12/11)
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- Acidification corrosion inhibitor based on interpolymer indolizine derivative as well as preparation method and application thereof
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The invention discloses an acidification corrosion inhibitor based on an interpolymer indolizine derivative as well as a preparation method and application thereof. The acidification corrosion inhibitor contains the interpolymer indolizine derivative; the interpolymer indolizine derivative is prepared by carrying out decarboxylation on heterocyclic alkali including (substituted) quinoline, (substituted) pyridine and the like, and carboxymethyl heterocyclic alkali quaternary ammonium salt obtained by alpha-haloacetic acid, and then carrying out intermolecular addition polymerization reaction onquaternary ammonium salt of the heterocyclic alkali including the (substituted) quinoline, the (substituted) pyridine and the like. The acidification corrosion inhibitor disclosed by the invention has relatively good corrosion inhibition performance under the condition that common corrosion inhibition synergists including alkynol and the like do not need to be compounded; the use amount of the acidification corrosion inhibitor is less and the acidification corrosion inhibitor can reach, even be better than the requirements of an acidification corrosion inhibitor performance testing method andfirst-grade to third-grade standards in evaluation indexes SY/T 5405-1996 when being independently used.
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Paragraph 0024
(2018/09/12)
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- Application of primary halogenated hydrocarbons for the synthesis of 3-Aryl and 3-Alkyl indolizines
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Indolizine is an important heterocyclic compound with several interesting properties that make it suitable for numerous applications in many fields, such as biology, medicine and materials. However, the synthesis of 3-Alkyl indolizines from bulky primary halogenated alkanes has not yet been reported. Herein, a transition-metal-free synthetic route to 3-Aryl and 3-Alkyl indolizines from electron-deficient alkenes, pyridines and primary halogenated hydrocarbons has been reported for the first time using a tandem reaction. The key step of this method is the oxidative dehydrogenative aromatization of a tetrahydroindolizine intermediate with 2,2,6,6-Tetramethylpiperidine-N-oxyl (TEMPO) as the oxidant. The advantages of this protocol are its use of easily available and low-cost starting materials, the transition-metal-free conditions and its ready scalability.
- Liu, Yan,Hu, Huayou,Zhou, Junyu,Wang, Wenhui,He, Youliang,Wang, Chao
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p. 5016 - 5024
(2017/07/10)
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- Pyridinium oxidations of benzyl alcohol under microwave-assisted retro-ene conditions
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Benzyl alcohol is oxidized to benzaldehyde when heated in sulfolane in the presence of N-benzylnicotinamide and N-benzylpyridinium salts. The oxidation is accelerated in the presence microwaves. Oxidations with related pyridiniums suggest that these oxidations could occur via retro-ene reactions.
- Jensen, Anton W.,Moore, John M.,Kimble, MaryEllen V.,Ausmus, Alex P.,Dilling, Wendell L.
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supporting information
p. 5636 - 5638
(2016/11/28)
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- Novel Chloroimidazolium-Based Ionic Liquids: Synthesis, Characterisation and Behaviour as Solvents to Control Reaction Outcome
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Novel ionic liquids containing chlorine atoms on the imidazolium cation were synthesised. The physicochemical properties of these ionic liquids were investigated extensively, including glass transition, melting and decomposition temperatures, density, vis
- Hawker, Rebecca R.,Panchompoo, Janjira,Aldous, Leigh,Harper, Jason B.
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p. 574 - 583
(2016/07/06)
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- Nitrogen: Versus phosphorus nucleophiles-how changing the nucleophilic heteroatom affects ionic liquid solvent effects in bimolecular nucleophilic substitution processes
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A series of nitrogen and phosphorus nucleophiles have been investigated to determine whether the previously established ionic liquid solvent effects on a bimolecular nucleophilic substitution (SN2) reaction vary with the nature of the nucleophilic centre. Reaction of group 15 triphenyl nucleophiles with benzyl bromide showed a different trend in the rate constant with increasing proportions of ionic liquid in the reaction mixture than was observed with pyridine. This result suggests additional interactions are important; a supposition supported by differences in reaction outcome observed when the electrophile was varied in reactions with triphenylphosphine. A novel ionic liquid solvent effect was observed in the reaction of tributylamine with benzyl bromide, with the position of equilibrium varying with the proportions of the ionic liquid present in the reaction mixture. Overall, the work presented demonstrates the importance of considering all possible interactions between an ionic liquid solvent and species along the reaction coordinate and has expanded upon our current predictive framework for ionic liquid solvent effects. Such understanding is important as it allows further development of a predictive framework for the application of ionic liquids in preparative chemistry.
- Schaffarczyk McHale, Karin S.,Hawker, Rebecca R.,Harper, Jason B.
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supporting information
p. 7437 - 7444
(2016/09/12)
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- Preparation, in vitro screening and molecular modelling of mono-quaternary compounds related to the selective acetylcholinesterase inhibitor BW284c51
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This paper describes preparation and in vitro evaluation of 19 compounds related to the selective experimental cholinesterase inhibitor BW284c51. The novel compounds were prepared as fragments of parent molecule BW284c51 and evaluated on the model of human recombinant acetylcholinesterase and human plasmatic butyrylcholinesterase. The IC50 values of the prepared compounds were compared to the parent molecule BW284c51. None of the compounds was superior to the parent drug, but two BW284c51 fragments showed promising hAChE inhibition in μM scale and improved selectivity. These two fragments were further subjected to the molecular modelling study and their enzyme interactions were rationalized. The structure-activity relationship of the prepared series was stated.
- Benek, Ondrej,Musilek, Kamil,Horova, Anna,Dohnal, Vlastimil,Dolezal, Rafael,Kuca, Kamil
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- Dynamic Covalent Chemistry of Nucleophilic Substitution Component Exchange of Quaternary Ammonium Salts
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Dynamic covalent libraries (DCLs) of quaternary ammonium cations were set up by reversible nucleophilic substitution (SN2′ and SN2) exchange reactions of ammonium salts and tertiary amines. The reactions were conducted at 60 °C to generate thermodynamically and kinetically controlled mixtures of quaternary ammonium compounds and tertiary amines, and were accelerated by using iodide as a nucleophilic catalyst. Microwave irradiation was used to assist the exchange reaction between the pyridinium salts and pyridine derivatives. Finally, experiments towards the generation of dynamic ionic liquids were performed. The results of this study pave the way for the extension of dynamic combinatorial chemistry to nucleophilic substitution reactions.
- Kulchat, Sirinan,Lehn, Jean-Marie
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p. 2484 - 2496
(2015/11/02)
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- One-pot synthesis of indolizine via 1,3-dipolar cycloaddition using a sub-equivalent amount of K2Cr2O7 as an efficient oxidant under base free conditions
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A one-pot method for synthesizing multi-substituted indolizines from α-halo-carbonyl compounds, pyridines and electron deficient alkenes was developed. A sub-equivalent amount of potassium dichromate was used as an oxidant under base free conditions. The transformation developed should be of economic efficiency.
- Wang, Chao,Hu, Huayou,Xu, Juanfang,Kan, Weiqiu
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p. 41255 - 41258
(2015/05/20)
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- Effect of Modifying the Anion of an Ionic Liquid on the Outcome of an SN2 Process
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The effect of a series of ionic liquids containing different anions (bis(trifluoromethanesulfonyl)imide, dicyanimide, hexafluorophosphate, tetrafluoroborate, and bromide) on the rate constant of a bimolecular substitution process was investigated. A gener
- Keaveney, Sinead T.,Francis, Dominic V.,Cao, Winnie,Haines, Ronald S.,Harper, Jason B.
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- Nitrogen-containing ionic liquids: Biodegradation studies and utility in base-mediated reactions
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Several ionic liquids (ILs) were prepared in order to study the susceptibility of various cores and substituents to biodegradability using the 'CO2 headspace' test (ISO 14593). Several of the ILs contained tertiary amine substituents and were tested as solvents and reagents for several base mediated processes including Suzuki-Miyaura, Sonogashira, Knoevenagel, and Morita-Baylis-Hilman reactions. It was found that although these ILs contain basic functionality, they do not promote base mediated reactions. Density functional theory molecular calculations confirmed that the protonation of these ILs is energetically unfavourable. Journal compilation
- Ford, Leigh,Ylijoki, Kai E.O.,Garcia, M. Teresa,Singer, Robert D.,Scammells, Peter J.
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p. 849 - 857
(2015/06/23)
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- INHIBITORS OF BRUTON'S TYROSINE KINASE
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The present invention provides a compound, solid forms, and compositions thereof, which are useful as inhibitors of Bruton's tyrosine kinase and which exhibit desirable characteristics for the same. The present invention also provides methods of making provided compound and solid forms.
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Paragraph 00126
(2014/01/08)
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- Modified fry cyanation of a chiral pyridinium salt: Asymmetric syntheses of (-)-coniine and (-)-solenopsin A
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The synthesis of chiral 2-cyano-Δ4-tetrahydropyridine 5 was carried out in 85 % yield through a modified two-step Fry reductive cyanation of pyridinium salt (+)-3c that used lithium triethylborohydride as the hydride donor. An alkylation-reduction sequence provided 2-alkyl-substituted tetrahydropyridines (+)-10a and (+)-10b in 72-75 % yield after chromatographic purification. This protocol has been applied to the asymmetric syntheses of piperidine alkaloids (-)-coniine and (-)-solenopsin A. The two-step reductive cyanation of chiral pyridinium salt (+)-3c afforded α-amino nitrile 5 in 85 % yield, which underwent an alkylation-reduction sequence followed by removal of the chiral moiety to yield the hemlock alkaloid (-)-coniine as its mandelate salt (>99:1 er). This reaction sequence was also used for the synthesis of the trans-2,6-disubstituted piperidine alkaloid (-)-solenopsin A. Copyright
- Vu, Van Ha,Jouanno, Laurie-Anne,Cheignon, Adele,Roisnel, Thierry,Dorcet, Vincent,Sinbandhit, Sourisak,Hurvois, Jean-Pierre
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p. 5464 - 5474
(2013/09/02)
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- Efficient and chemoselective reduction of pyridines to tetrahydropyridines and piperidines via rhodium-catalyzed transfer hydrogenation
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Promoted by iodide anion the rhodium complex dimer, [Cp RhCl 2]2, catalyzes efficiently the transfer hydrogenation of various quaternary pyridinium salts under mild conditions, affording not only piperidines but also 1,2,3,6-tetrahydropyridines in a highly chemoselective fashion, depending on the substitution pattern at the pyridinium ring. The reduction is conducted in azeotropic formic acid/triethylamine (HCOOH-Et 3N) mixture at 40 °C, with catalyst loadings as low as 0.005mol% being feasible. Copyright
- Wu, Jianjun,Tang, Weijun,Pettman, Alan,Xiao, Jianliang
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supporting information
p. 35 - 40
(2013/03/13)
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- Does the cation really matter? the effect of modifying an ionic liquid cation on an SN2 process
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The rate of reaction of a Menschutkin process in a range of ionic liquids with different cations was investigated, with temperature-dependent kinetic data giving access to activation parameters for the process in each solvent. These data, along with molecular dynamics simulations, demonstrate the importance of accessibility of the charged centre on the cation and that the key interactions are of a generalised electrostatic nature. The Royal Society of Chemistry.
- Tanner, Eden E. L.,Yau, Hon Man,Hawker, Rebecca R.,Croft, Anna K.,Harper, Jason B.
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supporting information
p. 6170 - 6175
(2013/09/12)
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- Nonconventional versus conventional application of pseudo-first-order kinetics to fundamental organic reactions
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Three new analysis procedures for pseudo-first-order kinetics are introduced and applied to eight different fundamental organic reactions. The reactions belong to the following classes: nitroalkane proton transfer, formal hydride ion transfers from NADH model compounds, and SN2 reactions of alkyl halides with ionic and neutral nucleophiles. The three methods consist of (1) half-life dependence of kapp, (2) sequential linear pseudo-first-order correlation, and (3) revised instantaneous rate constant analysis. Each of the three procedures is capable of distinguishing between one- and multistep mechanisms, and the combination of the three procedures provides a powerful strategy for differentiating between the two mechanistic possibilities. The data from the eight reactions chosen as examples clearly show how the procedures work in practice.
- Parker, Vernon D.,Hao, Weifang,Li, Zhao,Scow, Russell
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experimental part
p. 2 - 12
(2012/03/22)
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- 'One-pot' Hammett plots: A general method for the rapid acquisition of relative rate data
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A general 'one-pot' method for determining relative rates of reaction in complex mixtures has been established using free energy relationships to demonstrate its utility. Competition experiments involving as many as seven species gave relative rate consta
- Yau, Hon Man,Harper, Jason B.,Croft, Anna K.
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supporting information
p. 8937 - 8939,3
(2020/08/31)
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- Non-thermal internal energy distribution of ions observed in an electrospray source interfaced with a sector mass spectrometer
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The internal energy distribution P(Eint) of ions emitted in an electrospray (ESI) source interfaced with a sector mass spectrometer is evaluated by using the experimental survival yield (SY) method including the kinetic shift. This method is ba
- Rondeau, David,Galland, Nicolas,Zins, Emilie-Laure,Pepe, Claude,Drahos, Laszlo,Vekey, Karoly
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experimental part
p. 100 - 111
(2011/10/05)
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- Time-dependent slowly-reversible inhibition of monoamine oxidase A by N-substituted 1,2,3,6-tetrahydropyridines
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A novel class of N-substituted tetrahydropyridine derivatives was found to have multiple kinetic mechanisms of monoamine oxidase A inhibition. Eleven structurally similar tetrahydropyridine derivatives were synthesized and evaluated as inhibitors of MAO-A and MAO-B. The most potent MAO-A inhibitor in the series, 2,4-dichlorophenoxypropyl analog 12, displayed time-dependent mixed noncompetitive inhibition. The inhibition was reversed by dialysis, indicating reversible enzyme inhibition. Evidence that the slow-binding inhibition of MAO-A with 12 involves a covalent bond was gained from stabilizing a covalent reversible intermediate product by reduction with sodium borohydride. The reduced enzyme complex was not reversible by dialysis. The results are consistent with slowly reversible, mechanism-based inhibition. Two tetrahydropyridine analogs that selectively inhibited MAO-A were characterized by kinetic mechanisms differing from the kinetic mechanism of 12. As reversible inhibitors of MAO-A, tetrahydropyridine analogs are at low risk of having an adverse effect of tyramine-induced hypertension.
- Wichitnithad, Wisut,O'Callaghan, James P.,Miller, Diane B.,Train, Brian C.,Callery, Patrick S.
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experimental part
p. 7482 - 7492
(2012/02/02)
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- A convenient racemic synthesis of two isomeric tetrahydropyridyl alkaloids: Isoanatabine and anatabine
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(Chemical Equation Presented) Anatabine is a major alkaloid in Nicotiana tabacum and its isomer, isoanatabine, was recently found in a marine worm. Reduction of 1-methylpyridinium iodide with sodium borohydride gave 1-methyl-3-piperideine, which was transformed with hydrogen peroxide into the N-oxide. Reaction of the N-oxide successively with trifluoroacetic anhydride and potassium cyanide gave 2-cyano-1-methyl-3-piperideine. Its reaction with 3-pyridylmagnesium chloride gave (±)-N-methyl-isoanatabine. This was transformed with m-chloroperbenzoic acid into the N-oxide which was N-demethylated with iron(II) sulfate, giving (±)-isoanatabine. The successive applications of literature procedures for the N-demethylation by decomposition of N-oxide contributed to the knowledge of the mechanism of this oxidative rearrangement. On the other hand, the reduction of 1-methylpyridinium iodide with sodium borohydride and with potassium cyanide present since the start of the reaction in a two layer ether-water system, gave 2-cyano-1-methyl-4-piperideine. This was transformed into (±)-anatabine by the same sequence of reactions used for the synthesis of (±)- isoanatabine.
- Rouchaud, Anne,Kem, William R.
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body text
p. 569 - 581
(2010/09/05)
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- A one-pot domino reaction for the synthesis of 3-arylindolizines from pyridines, benzyl halides, and dihalide-substituted electron-deficient alkenes
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3-Arylindolizines were prepared by one-pot domino reactions from benzyl halides with pyridine (or isoquinoline) and cyclic or acyclic dihalide-substituted electron-deficient alkenes in the presence of potassium carbonate via in situ generated N-ylide intermediate. Both electron-donating and electron-withdrawing groups are tolerated in the aryl ring of benzyl halides. The yields range from moderate to high. Georg Thieme Verlag Stuttgart - New York.
- Hu, Huayou,Shi, Kunbo,Hou, Rongrong,Zhang, Zaichao,Zhu, Yulan,Zhou, Jianfeng
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experimental part
p. 4007 - 4014
(2011/02/22)
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- Solvent reorganisation as the driving force for rate changes of Menschutkin reactions in an ionic liquid
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The effect on the rate of reaction of each of a series of Menschutkin processes on changing from a molecular solvent to an ionic liquid was investigated. In each case, the rate acceleration observed at room temperature could be attributed to the change in
- Yau, Hon Man,Howe, Andrew G.,Hook, James M.,Croft, Anna K.,Harper, Jason B.
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supporting information; experimental part
p. 3572 - 3575
(2010/01/06)
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- 79Br NMR spectroscopy as a practical tool for kinetic analysis
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79Br NMR spectroscopy has been used to monitor a series of reactions in which the bromide ion is produced, including the Menschutkin reaction of pyridine with a range of substituted benzyl bromides and a Heck coupling process. In cases where the process could also be monitored using 1H NMR spectroscopy, the kinetic analyses using heteronuclear magnetic resonance spectroscopy were shown to be completely consistent. Both the utility of the process in following reactions which may be difficult to analyse using other techniques and the practical limitations associated with solvent choice are discussed. Copyright
- Chan, Si Jia,Howe, Andrew G.,Hook, James M.,Harper, Jason B.
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experimental part
p. 342 - 347
(2010/02/27)
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- Ibogaine analogues. Synthesis and preliminary pharmacological evaluation of 7-heteroaryl-2-azabicyclo[2.2.2]oct-7-enes
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Synthesis of 7-heteroaryl-2-azabicyclo[2.2.2]oct-7-enes by cycloaddition and subsequent cross-coupling reaction is described. Binding affinity of these novel compounds towards the characteristic receptorial targets of ibogaine is illustrated.
- Passarella, Daniele,Favia, Raffaele,Giardini, Alessandra,Lesma, Giordano,Martinelli, Marisa,Silvani, Alessandra,Danieli, Bruno,Efange, Simon M. N.,Mash, Deborah C.
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p. 1007 - 1014
(2007/10/03)
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- Polycations-12. The synthesis of liquid ionic phosphates (lips) from mono- and polycationic ammonium halides
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Preparations are reported for an extensive series of phosphate salts of polyammonium species from the corresponding halide salts. The phosphate salts, as anhydrous materials, are liquid at or near room temperature. Three approaches for the preparation of these materials are noted, including treatment with aqueous hexafluorophosphoric acid, classical ion exchange methods, and treatment with 85% phosphoric acid. The last of these provides the most desirable results. Several monocationic phosphate salts have also been prepared for comparison with other types of ionic liquids.
- Lall, Sharon,Behaj, Valbona,Mancheno, Danny,Casiano, Robert,Thomas, Marie,Rikin, Amir,Gaillard, Jennifer,Raju, Ravinder,Scumpia, Alexander,Castro, Steve,Engel, Robert,Cohen, JaimeLee Iolani
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p. 1530 - 1540
(2007/10/03)
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- Reactions of N-benzyl-pyridinium or -isoquinolinium ylides with ethyl 3-fluoro-3-(fluoroalkyl)acrylates to give fluoroalkyl-substituted indolizine and pyrrolo[2,1-a]isoquinoline derivatives
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In the presence of base, N-benzylpyridinium and N-benzylisoquinolinium ylides generated in situ from the N-benzyl-pyridinium or -isoquinolinium bromides react with ethyl 3-fluoro-3-fluoroalkyl(except bromodifluoromethyl)acrylates to give one or two fluoro
- Peng, Weimin,Zhu, Shizheng
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p. 3204 - 3210
(2007/10/03)
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- Alkylation process
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This invention relates to a process for the alkylation of aromatics by reacting an aromatic hydrocarbon with an olefin in the presence of an ionic liquid comprising (a) a compound of the formula Rn MX3-n wherein R is a C1-C6 alkyl radical, M is aluminium or gallium, X is a halogen atom and n is 0, 1 or 2 and, (b) a hydrocarbyl substituted imidazolium halide or a hydrocarbyl substituted pyridinium halide wherein at least one of the said hydrocarbyl substituents in the imidazolium halide is an alkyl group having 1-18 carbon atoms. The process allows ready separation of reaction products from the ionic liquid and improves selectivity to alkylated products.
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- Simple and rapid determination of the activation parameters of organic reactions by temperature-dependent NMR spectroscopy II. Application to reversible reactions
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A non-isothermal (NIT) method for evaluating the activation enthalpies and entropies of reactions in solutions was applied to several reversible reactions. This was realized by a stepwise elevation of the temperature of a reaction system using a variable-temperature apparatus comprising on NMR spectrometer and a quick collection of FID (free induction decay) at every plateau of the step. The rate from NIT experiments agreed well with the previously measured rates by the conventional methods.
- Satoh, Masahiro,Hirota, Minoru
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p. 2619 - 2624
(2007/10/03)
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- Conformational Analysis of N-Benzylpyridinium Bromide: A Comparison of Crystal Structure Data with Results of Semiempirical Calculations (MINDO/3, MNDO, AM1, and PM3)
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The conformation of the title compound 1b is investigated by X-ray analysis and semiempirical MO methods (MINDO/3, MNDO, AM1, PM3).For the calculation of bond lengths and bond angles, AM1 and MINDO/3 are superior.Without complete calculation of the hypers
- Anders, Ernst,Tropsch, Juergen G.,Irmer, Erhard,Sheldrick, George M.
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p. 321 - 325
(2007/10/02)
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- EFFECT OF STRUCTURAL FACTORS ON RATE OF BIMOLECULAR HOMOLYTIC SUBSTITUTION AT A CARBON ATOM IN BENZYL COMPLEXES OF COBALT
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The reaction of the benzylglyoximate complexes of cobalt with bromotrichloromethane leads to the formation of 1,1,1-trichloro-2-arylethanes, which correspond to bimolecular homolytic substitution of the cobalt-containing group by the trichloromethyl radic
- Dneprovskii, A. S.,Kasatochkin, A. N.,Kondakov, D. Yu.
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p. 833 - 838
(2007/10/02)
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- BIFUNCTIONAL MECHANISM OF CATALYSIS IN REACTIONS LEADING TO FORMATION OF α-AMINO KETONES
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The kinetics of the reaction of α-bromoacetophenone and benzyl bromide with aniline and pyridine in the presence of additions of acetic acid and phenol in benzene at 30 deg C were investigated.The catalytic effect due to the activity of the uncombined forms of the catalyst, their dimers, and their 1:1 complexes with the amines were separated quantitatively.The change in the catalytic activity of the respective particles in the solutions with variation in the structure of the reagents is examined, and possible mechanisms for the catalytic reactions are discussed on this basis.It is concluded that there is a bifunctional mechanism of catalysis by acetic acid in the reaction of α-bromoacetophenone with aniline.
- Popov, A. F.,Anikeev, A. V.
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p. 945 - 948
(2007/10/02)
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- 2-Cyano-Δ3-piperideines. 12. Stereochemistry of Formation of N-Benzyl-2-cyano-Δ3-piperideines and Facile Isomerization on Alumina to 2-Cyano-Δ4-piperideines. A Potentially General Route to the Synthesis of 2,6-Disubstitute
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The reaction of the piperideine N-oxides 1a-f with trifluoroacetic anhydride in CH2Cl2 at 0 deg C (Polonovski-Potier reaction) led to the formation of the N-benzyl-2-cyano-Δ3-piperideines 3a-f.Epimeric mixtures were obtained for the amino nitri
- Bonin, Martine,Romero, Jose Ricardo,Grierson, David S.,Husson, Henri-Philippe
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p. 2392 - 2400
(2007/10/02)
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- MUTUAL EFFECTS OF THE STRUCTURE IN THE REACTIONS OF BENZYL BROMIDES WITH PYRIDINES
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The rate of the reactions of benzyl bromides with pyridines in nitrobenzene at 40 deg C was measured.The nonadditivity of the joint action of the electronic effects of substituents in the molecules of the reagents on the reactivity of the benzyl bromide-p
- Shpan'ko, I. V.,Korostylev, A. P.,Shved, E. N.,Litvinenko, L. M.
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p. 1562 - 1565
(2007/10/02)
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- EFFECTS OF SUBSTITUENTS IN THE BENZYL BROMIDE ON THE KINETICS OF THE BENZYLATION OF AMINES
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The kinetics of the reactions of 3- and 4-substituted benzyl bromides with amines having various structures in nitrobenzene at 40 deg C were investigated.The 4-substituted benzyl bromides have higher reactivity compared with that calculated on the basis of the linear correlations according to the Hammett-Taft equation for unsubstituted and 3-substituted benzyl bromides containing electron-withdrawning substituents.The reactivity of benzyl bromides containing electron-donating substituents obeys a linear correlation with the ?+ constants.The effects of structural changes in the substrate and the nucleophile on the character of the transition states of the investigated reactions is discussed.
- Shpan'ko, I. V.,Korostylev, A. P.,Rusu, L. N.
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p. 1715 - 1723
(2007/10/02)
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