Nucleophilic substitution reactions of N-alkoxyimidoyl fluorides by carbon nucleophiles

2007 ◽  
Vol 85 (11) ◽  
pp. 913-922 ◽  
Author(s):  
Debra D Dolliver ◽  
David B Delatte ◽  
Derek B Linder ◽  
James E Johnson ◽  
Diana C Canesco ◽  
...  
Keyword(s):  
Substitution Reactions ◽  
Nucleophilic Substitutions ◽  
Degree Of Dissociation ◽  
Carbon Nucleophiles ◽  
Imine Form ◽  
Tautomeric Forms ◽  
Nmr Characterization ◽  
Ion Substitution ◽  
Carbon Acid ◽  
High Degree

Nucleophilic substitutions of N-alkoxybenzoimidoyl fluorides [p-ClArC(F)=NOR; R = CH3, i-Pr] by enolate-type ions have been performed to produce compounds that can exist in two tautomeric forms: the imine form{p-ClArC(Y)=NOR [Y = CH(CN)2, CH(CN)(CO2Et), CH(CO2Et)2]}or the enamine form {p-ClArC(NHOR)=C(R1)(R2) [R1, R2 = CN, CO2Et]}. These compounds display varying ratios of imine–enamine tautomerizm in chloroform: the diester compound exists almost solely in the imine form, the dicyano compound exists solely in the enamine form, and the cyano-ester compound exists in both tautomeric forms. Comparison of the imine–enamine equilibrium in chloroform of the cyano-ester compound to an analogue where the p-ClAr group has been replaced by a methyl group reveals that the aromatic ring has a significant effect on the imine–enamine distribution. The former exists in both the imine and enamine form, while the latter exists solely in the enamine form. Complete NMR characterization data for the enamine form of CH3C(NHOCH3)=C(CN)(CO2Et) is also reported. The acidity of p-ClArC(NHOR)=C(CN)2 is demonstrated by a high degree of dissociation of the enamine proton in DMSO. Substitution reactions of p-ClArC(F)=NOi-Pr by Grignard reagents (PhMgBr, CH3MgBr, and PhCCMgBr) have also been performed to produce single geometric isomers of p-ClArC(Ph)=NOi-Pr, p-ClArC(CCPh)=NOi-Pr, and p-ClArC(CH3)=NOi-Pr. A modified synthesis of N-alkoxyimidoyl fluorides, which prevents a competing reaction of the product with the solvent, is reported.Key words: N-alkoxyimidoyl fluoride, enolate ion substitution, Grignard substitution, imine–enamine tautomerizm, carbon acid.

Organic Reactivity in Ionic Liquids: Some Mechanistic Insights into Nucleophilic Substitution Reactions

2005 ◽  
Vol 2005 (7) ◽  
pp. 413-417 ◽  
Author(s):  
N. Llewellyn Lancaster
Keyword(s):  
Ionic Liquids ◽  
Nucleophilic Substitution ◽  
Organic Reactions ◽  
Substitution Reactions ◽  
Nucleophilic Substitutions ◽  
Nucleophilic Substitution Reactions ◽  
Quantitative Studies ◽  
Alternative Solvents ◽  
Molecular Solvents ◽  
Organic Reactivity

Ionic liquids have been advanced as alternative solvents for organic reactions. In this paper, the principal findings of studies on nucleophilic substitutions in ionic liquids are reviewed. Thus our examination of halides (Cl-, Br- and I) in a range of ionic liquids is combined with our study of amine nucleophilicity into a single narrative. There have been a few other quantitative studies of nucleophilic substitutions in ionic liquids, and the results of these studies are also summarised in this work. These data are compared to related reactions in molecular solvents, and used to show where ionic liquids do (and do not) offer advantages over molecular solvents for nucleophilic substitutions.

Reaction-path calculations and crystal structures of 1,1′-(ethylene-1,2-diyl)dipyridinium dichloride dihydrate and 1,1′-(ethylene-1,2-diyl)dipyridinium dibromide

2016 ◽  
Vol 72 (2) ◽  
pp. 112-118
Author(s):  
Mwaffak Rukiah ◽  
Mahmoud M. Al-Ktaifani ◽  
Mohammad K. Sabra
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Materials Science ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Substitution Reactions ◽  
Nucleophilic Substitutions ◽  
Triclinic Space Group ◽  
Pyridinium Bromide ◽  
Multinuclear Nmr Spectroscopy

The design of new organic–inorganic hybrid ionic materials is of interest for various applications, particularly in the areas of crystal engineering, supramolecular chemistry and materials science. The monohalogenated intermediates 1-(2-chloroethyl)pyridinium chloride, C5H5NCH2CH2Cl+·Cl−, (I′), and 1-(2-bromoethyl)pyridinium bromide, C5H5NCH2CH2Br+·Br−, (II′), and the ionic disubstituted products 1,1′-(ethylene-1,2-diyl)dipyridinium dichloride dihydrate, C12H14N22+·2Cl−·2H2O, (I), and 1,1′-(ethylene-1,2-diyl)dipyridinium dibromide, C12H14N22+·2Br−, (II), have been isolated as powders from the reactions of pyridine with the appropriate 1,2-dihaloethanes. The monohalogenated intermediates (I′) and (II′) were characterized by multinuclear NMR spectroscopy, while (I) and (II) were structurally characterized using powder X-ray diffraction. Both (I) and (II) crystallize with half the empirical formula in the asymmetric unit in the triclinic space groupP\overline{1}. The organic 1,1′-(ethylene-1,2-diyl)dipyridinium dications, which display approximateC2hsymmetry in both structures, are situated on inversion centres. The components in (I) are linkedviaintermolecular O—H...Cl, C—H...Cl and C—H...O hydrogen bonds into a three-dimensional framework, while for (II), they are connectedviaweak intermolecular C—H...Br hydrogen bonds into one-dimensional chains in the [110] direction. The nucleophilic substitution reactions of 1,2-dichloroethane and 1,2-dibromoethane with pyridine have been investigated byab initioquantum chemical calculations using the 6–31G** basis. In both cases, the reactions occur in two exothermic stages involving consecutive SN2 nucleophilic substitutions. The isolation of the monosubstituted intermediate in each case is strong evidence that the second step is not fast relative to the first.

Deposition of Diamond-Like Carbon Films by Excimer Lasers Using Frozen Source Gases

1995 ◽  
Vol 397 ◽  
Author(s):  
Mitsugu Hanabusa ◽  
Kiyohito Tsujihara ◽  
Liu Zhengxin ◽  
Seiji Ishihara ◽  
Hironaga Uchida
Keyword(s):  
Carbon Films ◽  
Diamond Like Carbon ◽  
Degree Of Dissociation ◽  
Arf Laser ◽  
Frozen Gases ◽  
Quartz Substrates ◽  
High Degree ◽  
Power Densities ◽  
Deposited Films ◽  
Number Of Particles

ABSTRACTWe deposited diamond-like carbon (DLC) films, using frozen acetylene and acetone as the target of laser ablation. The frozen gases were dissociated by an ArF laser and a KrF laser. The DLC films were deposited on quartz substrates below 300°C. We measured the Raman spectra to identify the deposited films as DLC. The films showed the broad Raman peak at 1540 cm-1. The number of particles mixed into the deposits was controlled by laser power densities. By using the ArF laser for frozen acetylene we could reduce the hydrogen concentration in the films, which showed a high degree of dissociation of the source gas. The oxygen content was kept at the same level in the films deposited from frozen acetone as from frozen acetylene. The present results suggested the importance of energetic and charged species ejected from the frozen gas target.

Mechanism of amine and amide ion substitution reactions at the carbon-nitrogen double bond

1985 ◽  
Vol 50 (18) ◽  
pp. 3348-3355 ◽  
Author(s):  
James Elver Johnson ◽  
Abdolkarim Ghafouripour ◽  
Mohammad Arfan ◽  
Susan L. Todd ◽  
Deborah A. Sitz
Keyword(s):  
Double Bond ◽  
Substitution Reactions ◽  
Ion Substitution ◽  
Nitrogen Double Bond

scholarly journals Thermodynamic properties of isoprene and monoterpene derived organosulfates estimated with COSMO<i>therm</i>

2019 ◽  
Author(s):  
Noora Hyttinen ◽  
Jonas Elm ◽  
Jussi Malila ◽  
Silvia M. Calderón ◽  
Nønne L. Prisle
Keyword(s):  
Thermodynamic Properties ◽  
Vapor Pressures ◽  
Aqueous Mixtures ◽  
Ambient Conditions ◽  
Salting Out ◽  
Degree Of Dissociation ◽  
Range Transport ◽  
High Degree ◽  
Saturation Vapor ◽  
Atmospherically Relevant

Abstract. Organosulfates make significant contributions to atmospheric secondary organic aerosol (SOA), but little is still known about the thermodynamic properties of atmospherically relevant organosulfates. We have used the COSMOtherm program to calculate both gas- and condensed-phase properties of previously identified atmospherically relevant monoterpene and isoprene derived organosulfates. Properties include solubilities, activities and saturation vapor pressures, which are critical to the aerosol phase stability and atmospheric impact of organosulfate SOA. Based on the estimated saturation vapor pressures, the organosulfates of this study can all be categorized as semi- or low-volatile, with saturation vapor pressures 4 to 8 orders of magnitude lower than that of sulfuric acid. The estimated pKa values of all the organosulfates indicate a high degree of dissociation in water, leading in turn to high dissociation corrected solubilities. In aqueous mixtures with inorganic sulfate, COSMOtherm predicts a salting out of both the organosulfates and their sodium salts from inorganic co-solutes. The salting-out effect of ammonium sulfate (less acidic) is stronger than of ammonium bisulfate (more acidic). Finally, COSMOtherm predicts liquid-liquid phase separation in systems containing water and monoterpene derived organosulfates. The COSMOtherm estimated properties support the observed stability of organosulfates as SOA constituents and their long range transport in the atmosphere, but also show significant variation between specific compounds and ambient conditions.

scholarly journals Thermodynamic properties of isoprene- and monoterpene-derived organosulfates estimated with COSMO<i>therm</i>

2020 ◽  
Vol 20 (9) ◽  
pp. 5679-5696 ◽  
Author(s):  
Noora Hyttinen ◽  
Jonas Elm ◽  
Jussi Malila ◽  
Silvia M. Calderón ◽  
Nønne L. Prisle
Keyword(s):  
Thermodynamic Properties ◽  
Vapor Pressures ◽  
Aqueous Mixtures ◽  
Ambient Conditions ◽  
Salting Out ◽  
Degree Of Dissociation ◽  
Range Transport ◽  
High Degree ◽  
Saturation Vapor ◽  
Atmospherically Relevant

Abstract. Organosulfates make significant contributions to atmospheric secondary organic aerosol (SOA), but little is known about the thermodynamic properties of atmospherically relevant organosulfates. We have used the COSMOtherm program to calculate both the gas- and condensed-phase properties of previously identified atmospherically relevant monoterpene- and isoprene-derived organosulfates. Properties include solubilities, activities and saturation vapor pressures, which are critical to the aerosol-phase stability and atmospheric impact of organosulfate SOA. Based on the estimated saturation vapor pressures, the organosulfates of this study can all be categorized as semi-volatile or low-volatile, with saturation vapor pressures 4 to 8 orders of magnitude lower than that of sulfuric acid. The estimated pKa values of all the organosulfates indicate a high degree of dissociation in water, leading in turn to high dissociation-corrected solubilities. In aqueous mixtures with inorganic sulfate, COSMOtherm predicts a salting-out of both the organosulfates and their sodium salts from inorganic co-solutes. The salting-out effect of ammonium sulfate (less acidic) is stronger than of ammonium bisulfate (more acidic). Finally, COSMOtherm predicts liquid–liquid-phase separation in systems containing water and monoterpene-derived organosulfates. The COSMOtherm-estimated properties support the observed stability of organosulfates as SOA constituents and their long-range transport in the atmosphere but also show significant variation between specific compounds and ambient conditions.

ChemInform Abstract: Substitution Reactions of 2-Benzenesulfonyl Cyclic Ethers with Carbon Nucleophiles.

ChemInform ◽  
1989 ◽  
Vol 20 (45) ◽  
Author(s):  
D. S. BROWN ◽  
M. BRUNO ◽  
R. J. DAVENPORT ◽  
S. V. LEY
Keyword(s):  
Cyclic Ethers ◽  
Substitution Reactions ◽  
Carbon Nucleophiles

High Degree of Dissociation of Nitrogen Molecules in Large-Volume Electron-Beam-Excited Plasma

2000 ◽  
Vol 39 (Part 2, No. 10A) ◽  
pp. L999-L1001 ◽  
Author(s):  
Kazunari Taniguchi ◽  
Masaya Sugimoto ◽  
Shingo Masuko ◽  
Toshihiro Kobayashi ◽  
Manabu Hamagaki ◽  
...  
Keyword(s):  
Electron Beam ◽  
Large Volume ◽  
Degree Of Dissociation ◽  
High Degree

Synthesis of aromatic functionalized cage-rearranged silsesquioxanes (T8, T10, and T12) via nucleophilic substitution reactions

2015 ◽  
Vol 44 (3) ◽  
pp. 916-919 ◽  
Author(s):  
Supansa Chimjarn ◽  
Rungthip Kunthom ◽  
Prapassorn Chancharone ◽  
Rapheepraew Sodkhomkhum ◽  
Preeyanuch Sangtrirutnugul ◽  
...  
Keyword(s):  
Nucleophilic Substitution ◽  
Building Blocks ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Substitution Reactions ◽  
Nucleophilic Substitutions ◽  
Inorganic Hybrid ◽  
Nucleophilic Substitution Reactions

Organic–inorganic hybrid nano-building blocks of aryl nitro-, aldehyde-, and bromo-functionalized polyhedral oligomeric silsesquioxanes (T8, T10, and T12) were easily prepared through nucleophilic substitutions.

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