- Overriding Intrinsic Reactivity in Aliphatic C?H Oxidation: Preferential C3/C4 Oxidation of Aliphatic Ammonium Substrates
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The site-selective C?H oxidation of unactivated positions in aliphatic ammonium chains poses a tremendous synthetic challenge, for which a solution has not yet been found. Here, we report the preferential oxidation of the strongly deactivated C3/C4 positions of aliphatic ammonium substrates by employing a novel supramolecular catalyst. This chimeric catalyst was synthesized by linking the well-explored catalytic moiety Fe(pdp) to an alkyl ammonium binding molecular tweezer. The results highlight the vast potential of overriding the intrinsic reactivity in chemical reactions by guiding catalysis using supramolecular host structures that enable a precise orientation of the substrates.
- Heilmann, Michael,Knezevic, Melina,Piccini, Giovanni Maria,Tiefenbacher, Konrad
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- Supramolecular recognition allows remote, site-selective C-H oxidation of methylenic sites in linear amines
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Site-selective C-H functionalization of aliphatic alkyl chains is a longstanding challenge in oxidation catalysis, given the comparable relative reactivity of the different methylenes. A supramolecular, bioinspired approach is described to address this challenge. A Mn complex able to catalyze C(sp3)-H hydroxylation with H2O2 is equipped with 18-benzocrown-6 ether receptors that bind ammonium substrates via hydrogen bonding. Reversible pre-association of protonated primary aliphatic amines with the crown ether selectively exposes remote positions (C8 and C9) to the oxidizing unit, resulting in a site-selective oxidation. Remarkably, such control of selectivity retains its efficiency for a whole series of linear amines, overriding the intrinsic reactivity of C- H bonds, no matter the chain length.
- Olivo, Giorgio,Farinelli, Giulio,Barbieri, Alessia,Lanzalunga, Osvaldo,Di Stefano, Stefano,Costas, Miquel
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- Deoxygenative hydroboration of primary, secondary, and tertiary amides: Catalyst-free synthesis of various substituted amines
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Transformation of relatively less reactive functional groups under catalyst-free conditions is an interesting aspect and requires a typical protocol. Herein, we report the synthesis of various primary, secondary, and tertiary amines through hydroboration of amides using pinacolborane under catalyst-free and solvent-free conditions. The deoxygenative hydroboration of primary and secondary amides proceeded with excellent conversions. The comparatively less reactive tertiary amides were also converted to the corresponding N,N-diamines in moderate yields under catalyst-free conditions, although alcohols were obtained as a minor product.
- An, Duk Keun,Jaladi, Ashok Kumar,Kim, Hyun Tae,Yi, Jaeeun
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- Method for synthesizing N, N-dimethyl decylamine by using tetrapolypropylene and hydrocyanic acid
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The invention discloses a method for synthesizing N, N-dimethyl decylamine by using tetrapolypropylene and hydrocyanic acid, and relates to the technical field of comprehensive development, extension and utilization of petrochemical products, which comprises the following steps: by using tetrapolypropylene and acrylonitrile byproduct hydrocyanic acid as initial raw materials, adding tetrapolypropylene and a solvent into a reaction kettle; and dropwise adding hydrocyanic acid and a catalyst in a cooling and stirring state, carrying out a heat preservation reaction after dropwise adding is finished, then adding methanol and pure water after the heat preservation reaction is finished, carrying out a stirring reaction, and carrying out neutralization, standing phase splitting, distillation purification and the like after the stirring reaction is finished to prepare N, N-dimethyl decylamine. The invention researches and develops a new synthesis process of N, N-dimethyl decylamine, develops a new high-added-value utilization way of the byproduct hydrocyanic acid of tetrapolypropylene and acrylonitrile, enables the industrial chain of the byproduct hydrocyanic acid of tetrapolypropylene and acrylonitrile which are propylene downstream products to extend to fine chemical products, and improves the economic benefits of the propylene downstream industrial chain products.
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Paragraph 0018-0026
(2021/04/07)
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- Dimethylamination of Primary Alcohols Using a Homogeneous Iridium Catalyst: A Synthetic Method for N, N-Dimethylamine Derivatives
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A new catalytic system for N,N-dimethylamination of primary alcohols using aqueous dimethylamine in the absence of additional organic solvents has been developed. The reaction proceeds via borrowing hydrogen processes, which are atom-efficient and environmentally benign. An iridium catalyst bearing an N-heterocyclic carbene (NHC) ligand exhibited high performance, without showing any deactivation under aqueous conditions. In addition, valuable N,N-dimethylamine derivatives, including biologically active and pharmaceutical molecules, were synthesized. The practical application of this methodology was demonstrated by a gram-scale reaction.
- Jeong, Jaeyoung,Fujita, Ken-Ichi
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p. 4053 - 4060
(2021/03/09)
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- Scalable synthesis of salt-free quaternary ammonium carboxylate catanionic surfactants
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Surfactants in commercial products commonly contain catanionic mixtures thus many studies of aqueous surfactant mixtures have been carried out. However, hardly any studies have been dedicated to pure catanionic surfactants often termed salt-free catanionic surfactants. One of the difficulties is in acquirement of samples with required purity due to difficult separation of these compounds from inorganic salts. In this work we present an alternative method of synthesis using dimethyl carbonate as the alkylating agent in order to obtain alkyl trimethylammonium alkanecarboxylates with medium alkyl chain lengths (6-10).
- ?tanfel, Ur?a,?ener, Bo?tjan,Be?ter-Roga?, Marija,Ko?mrlj, Janez,Medo?, ?iga,Virant, Miha
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p. 270 - 275
(2020/04/01)
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- Molecular Catalysts for Selective Hydrogenolysis of Amides
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A compound by the name 1,1,1-tris(di(3,5-dimethoxyphenyl)phosphino-methyl)ethane. The compound can be represented by the structure of formula (I): The compound is useful as a ligand for ruthenium to form an organometallic complex. The complex is an active catalyst for the hydrogenolysis of amides to form amines and optionally alcohols.
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Paragraph 0083-0084
(2019/11/22)
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- Cationic linear chloramine antibacterial agent and synthesis method thereof
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The invention belongs to the technical field of synthesis and application of chloramine antibacterial agents, and provides a synthesis method of a cationic linear chloramine antibacterial agent. N-tert-butyl-chloroalkylamide II and a compound IV are used as raw materials to prepare a chloramine precursor compound III, then to be reacted with tert-butyl hypochlorite at a room temperature to preparea chloramine compound I; and the compound IV is one of a tertiary amine compound IV1 with different alkyl chains, a pyridine compound IV2 with different alkyl chains and tributyl phosphine. Accordingto the preparation method, when use of potassium cyanide is avoided, different cation structures are introduced into linear chloramine molecules to improve water solubility and improve the antibacterial activity; moreover, the structure of long alkyl chains and the chloramine structure introduced into the cation center can produce the strong synergistic antibacterial effect, and the antibacterialactivity is significantly improved compared with hydantoin like chloramine; and the theoretical basis is hopefully provided for preparation of high-efficiency cationic chloramine antibacterial materials .
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Paragraph 0069-0071
(2019/11/12)
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- N-Methylation of amines and nitroarenes with methanol using heterogeneous platinum catalysts
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We report herein the selective N-methylation of amines and nitroarenes with methanol under basic conditions using carbon-supported Pt nanoparticles (Pt/C) as a heterogeneous catalyst. This method is widely applicable to four types of N-methylation reactions: (1) N,N-dimethylation of aliphatic amines under N2, (2) N-monomethylation of aliphatic amines under 40 bar H2, (3) N-monomethylation of aromatic amines under N2, and (4) tandem synthesis of N-methyl anilines from nitroarenes and methanol under 2 bar H2. All these reactions under the same catalytic system showed high yields of the corresponding methylamines for a wide range of substrates, high turnover number (TON), and good catalyst reusability. Mechanistic studies suggested that the reaction proceeded via a borrowing hydrogen methodology. Kinetic results combined with density functional theory (DFT) calculations revealed that the high performance of Pt/C was ascribed to the moderate metal–hydrogen bond strength of Pt.
- Jamil, Md.A.R.,Touchy, Abeda S.,Rashed, Md. Nurnobi,Ting, Kah Wei,Siddiki, S.M.A. Hakim,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-ichi
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- Reduction and Reductive Deuteration of Tertiary Amides Mediated by Sodium Dispersions with Distinct Proton Donor-Dependent Chemoselectivity
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A practical and scalable single electron transfer reduction mediated by sodium dispersions has been developed for the reduction and reductive deuteration of tertiary amides. The chemoselectivity of this method highly depends on the nature of the proton donor. The challenging reduction via C-N bond cleavage has been achieved using Na/EtOH, affording alcohol products, while the use of Na/NaOH/H2O leads to the formation of amines via selective C-O scission. Sodium dispersions with high specific surface areas are crucial to obtain high yields and good chemoselectivity. This new method tolerates a range of tertiary amides. Moreover, the corresponding reductive deuterations mediated by Na/EtOD-d1 and Na/NaOH/D2O afford useful α,α-dideuterio alcohols and α,α-dideuterio amines with an excellent deuterium content.
- Zhang, Bin,Li, Hengzhao,Ding, Yuxuan,Yan, Yuhao,An, Jie
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p. 6006 - 6014
(2018/05/24)
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- Controlled Reduction of Tertiary Amides to the Corresponding Alcohols, Aldehydes, or Amines Using Dialkylboranes and Aminoborohydride Reagents
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Dialkylboranes and aminoborohydrides are mild, selective reducing agents complementary to the commonly utilized amide reducing agents, such as lithium aluminum hydride (LiAlH4) and diisobutylaluminum hydride (DIBAL) reagents. Tertiary amides were reduced using 1 or 2 equiv of various dialkylboranes. The reduction of tertiary amides required 2 equiv of 9-borabicyclo[3.3.1]nonane (9-BBN) for complete reduction to give the corresponding tertiary amines. One equivalent of sterically hindered disiamylborane reacts with tertiary amides to afford the corresponding aldehydes. Aminoborohydrides are powerful and selective reducing agents for the reduction of tertiary amides. Lithium dimethylaminoborohydride and lithium diisopropylaminoborohydride are prepared from n-butyllithium and the corresponding amine-borane. Chloromagnesium dimethylaminoborohydride (ClMg+[H3B-NMe2]-, MgAB) is prepared by the reaction of dimethylamine-borane with methylmagnesium chloride. Solutions of aminoborohydride reduce aliphatic, aromatic, and heteroaromatic tertiary amides to give the corresponding alcohol, amine, or aldehyde depending on the steric requirement of the tertiary amide and the aminoborohydride used.
- Bailey, Christopher L.,Joh, Alexander Y.,Hurley, Zefan Q.,Anderson, Christopher L.,Singaram, Bakthan
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p. 3619 - 3628
(2016/05/24)
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- Methylformate as replacement of syngas in one-pot catalytic synthesis of amines from olefins
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A new general approach for the one-pot hydroaminomethylation of olefins using methylformate as formylating agent instead of synthesis gas (syngas) has been proposed. Herein we report that a Ru-Rh catalytic system demonstrates high activity in a tandem conversion of a series of n-alkenes into amines using methylformate with yields 58-92% (6 h). The selectivity for the normal amine reached 96% with catalysis by the Ru carbonyl complex Ru3(CO) 12, with an overall yield of 55% with respect to amine in this instance. The addition of the Rh complex to Ru catalytic system, sharply increased the hydroaminomethylation rate of both the terminal and internal alkenes and increased the yield of amines to 82-93% (6-12 h). The Royal Society of Chemistry.
- Karakhanov, Eduard,Maksimov, Anton,Kardasheva, Yulia,Runova, Elena,Zakharov, Roman,Terenina, Maria,Kenneally, Corey,Arredondo, Victor
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p. 540 - 547
(2014/02/14)
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- Catalytic aminomethylation of alkenes in a dimethylformamide medium
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The hydroaminomethylation of alkenes with dimethylamine catalyzed by rhodium and ruthenium complexes in a dimethylformamide medium under synthesis-gas pressures of 2 MPa has been studied. It has been shown that the combined use of these metals leads to a significant increase in the rate of formation of amines and selectivity for n-alkyldimethylamine. It has been found that the reaction can proceed with dimethylformamide used as an aminating agent without the addition of dimethylamine. Pleiades Publishing, Ltd., 2012.
- Karakhanov,Runova,Kardasheva,Losev,Maksimov,Terenina
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experimental part
p. 179 - 185
(2012/07/28)
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- Functional group-selective poisoning of molecular catalysts: A ruthenium cluster-catalysed highly amide-selective silane reduction that does not affect ketones or esters
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The addition of amines eliminates the catalytic activity of a triruthenium cluster in the hydrosilane reduction of ketones and esters without affecting the rate of reduction of amides; selective reduction of the amide group in amido ketones and amido esters is accomplished. The Royal Society of Chemistry.
- Sasakuma, Hidehiro,Motoyama, Yukihiro,Nagashima, Hideo
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p. 4916 - 4918
(2008/09/17)
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- Process for obtaining amines by reduction of amides
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Disclosed is a process for the preparation of primary, secondary and tertiary amines via a catalytic hydrogenation of unsubstituted, N-substituted, and N,N- disubstituted amides. The amide is led, together with an auxiliary amine, in vaporised form in a hydrogen containing gas flow over the catalyst. The process can be carried out at relatively low pressures, between 2 and 50 bars, using typical hydrogenation catalysts like CuCr-type catalysts. The amine is obtained with high yield and high selectivity. The process can be carried out in a continuous fixed bed reactor.
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Page/Page column 6
(2008/06/13)
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- Process for obtaining amines by reduction of amides
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Disclosed is a process for the preparation of primary, secondary and tertiary amines via a catalytic hydrogenation of unsubstituted, N-substituted, and N,N-disubstituted amides. The amide is led, together with an auxiliary amine, in vaporised form in a hydrogen containing gas flow over the catalyst. The process can be carried out at relatively low pressures, between 2 and 50 bars, using typical hydrogenation catalysts like CuCr-type catalysts. The amine is obtained with high yield and high selectivity. The process can be carried out in a continuous fixed bed reactor.
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Page/Page column 4
(2008/06/13)
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- PROCESS FOR OBTAINING AMINES BY REDUCTION OF AMIDES
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Disclosed is a process for the preparation of primary, secondary and tertiary amines via a catalytic hydrogenation of unsubstituted, N- substituted, and N,N- disubstituted amides. The amide is led, together with an auxiliary amine, in vaporised form in a hydrogen containing gas flow over the catalyst. The process can be carried out at relatively low pressures, between 2 and 50 bars, using typical hydrogenation catalysts like CuCr-type catalysts. The amine is obtained with high yield and high selectivity. The process can be carried out in a continuous fixed bed reactor.
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Page/Page column 11-12
(2008/06/13)
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- PROCESS FOR PRODUCTION OF TERTIARY AMINES
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A process for producing a tertiary amine from an alcohol and a primary or secondary amine by use of a film type catalyst, which comprises circulating the reaction fluid through a reaction tank equipped with an external circulation line packed with the film type catalyst at a rate of at least three times/h to conduct the reaction.
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Page/Page column 16-18
(2008/06/13)
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- A novel strategy for oligopeptide synthesis using a polymer-supported ammonium fluoride
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A novel method for the preparation of oligopeptides with a PS-ammonium fluoride in the solution phase is reported. The synthesis of lipid II pentapeptide is efficiently synthesized via a PS-ammonium fluoride without chromatographic purifications. The method reported here is very convenient to synthesize a relatively large amount of oligopeptides with abundantly available Fmoc-protected amino acids in a time efficient manner.
- Kurosu, Michio,Crick, Dean C.
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p. 5325 - 5328
(2007/10/03)
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- Controlled reduction of tertiary amides to the corresponding aldehydes or amines using dialkylboranes
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Several tertiary amides were reduced using one or two equivalents of various dialkylboranes, such as 9-borabicyclo[3.3.1] nonane (9-BBN), dicyclohexylborane (Chx2BH), or disiamylborane (Sia2BH). The reduction of tertiary amides having alkyl substituents of varying steric requirement at the nitrogen atom, required two equivalents of 9-BBN for complete reduction and gave the corresponding tertiary amines. However, sterically more hindered dialkylboranes such as Chx2BH and Sia2BH, reacted in 1:1 stoichiometry with tertiary amides and partially reduced them to the corresponding aldehydes.
- Godjoian, Gayane,Singaram, Bakthan
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p. 1717 - 1720
(2007/10/03)
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- Concentration of hydrophobic organic compounds and extraction of protein using alkylammoniosulfate zwitterionic surfactant mediated phase separations (cloud point extractions)
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The zwitterionic surfactants 3-[nonyl- (or decyl-) dimethylammonio]propyl sulfate, (C9-APSO4 or C10-APSO4) were synthesized using Nilsson's procedure, and their phase separation behavior under different experimental conditions was evaluated. The results indicate that such zwitterionic surfactants can be utilized for the extraction/preconcentration of hydrophobic species in a manner akin to that previously reported for nonionic surfactants. This was demonstrated for several practical applications including the extraction/preconcentration of some steroidal hormones and vitamin E prior to high-performance liquid chromatography analysis. The zwitterionic surfactant mediated phase separation was also applied to the extraction of the hydrophobic membrane protein, bacterio-rhodopsin, from the hydrophilic cytochrome c protein, both originally present In an aqueous phase. The concentration factors for this aqueous two-phase extraction technique using C10-APSO4 ranged from 26 to 35 with recoveries In the range 88 to > 96%. Some comparative studies Indicate that the use of zwittterionic surfactants In lieu of nonionic surfactants (e.g. polyoxyethylene(7.5) nonyl phenyl ether PONPE-7.5) In such an extraction method offers some significant advantages such as purer, homogeneous surfactant preparation, minimum background absorbance at UV detection wavelengths, the two-phase region occurring at lower temperatures, and greater extraction efficiencies/concentration factors among others.
- Saitoh, Tohru,Hinze, Willie L.
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p. 2520 - 2525
(2007/10/02)
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- Aminoborohydrides as Reducing Agents. 1. Sodium (Dimethylamino)- and (tert-Butylamino)borohydrides as Selective Reducing Agents
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Replacement of a hydride in borohydride by an electron-donating alkylamino group greatly enhances the reducing ability of the resulting reagents.Thus, sodium (dimethylamino)- and (tert-butylamino)borohydrides (1, NaDMAB, and 2, NaTBAB, respectively) not only reduce aldehydes and ketones to alcohols but also are effective for the conversion of esters to alcohols and primary amides to amines in good to excellent yields.Tertiary amides are reduced to alcohols (i.e., N,N-dimethylamides) or amines (i.e.N,N-diisopropylamides) depending on the steric bulk of the alkyl substituents on nitrogen.However, secondary amides are not reduced by the reagents allowing selective conversion of primary and tertiary amides in the presence of secondary amides.Nitriles are attacked by the reagents but do not afford synthetically useful amounts of amine products.Aryl halides are slowly converted to arenes, but alkyl halides and epoxides undergo unusual reactions with the amino portion of the reagents.
- Hutchins, Robert O.,Learn, Keith,El-Telbany, Farag,Stercho, Yuriy P.
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p. 2438 - 2443
(2007/10/02)
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- Base-catalysed Rearrangements involvung Ylide Intermediates. Part 8. The Preparation and Some Reactions of Stable Ammonium Ylides
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The carbonyl-stabilised ammonium ylides (3), (12a-n), and (14a-c) were obtained from the reaction of the corresponding ammonium halides (1), (13a-n), and (15a-c) with sodium hydroxide in water or aqueous methanol.The ylides, which were characterised by their molecular formulae and spectroscopic properies, regenerated quaternary ammonium bromides on treatment with hydrobromic acid.In general the reactions of the ammonium ylides resemble those of the corresponding sulphonium ylides.Thus ylides having a suitable migrating group (ArCH2) undergo a Stevens rearrangement on heating, and other ylides fragment to give a tertiary amine and products containing the PhCOCH grouping.A number of ylides reacted with dimethyl acetylenedicarboxylate to give the furans (32).The ylides (14b and c) with phenyl isocyanate gave the phenylcarbamoyl-substituted ylides.
- Jemison, Robert W.,Mageswaran, Sivapathasuntharam,Ollis, W. David,Sutherland, Ian O.,Thebtaranonth, Yodhathai
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p. 1154 - 1164
(2007/10/02)
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