Nickel-catalysed hydrogen exchange of alkylaromatic hydrocarbons and toluic acid derivatives with deuterium oxide

1965 ◽  
Vol 18 (7) ◽  
pp. 1009 ◽  
Author(s):  
CG Macdonald ◽  
JS Shannon
Keyword(s):  
Carbon Atom ◽  
Alkyl Group ◽  
Hydrogen Exchange ◽  
Deuterium Oxide ◽  
Dissociative Adsorption ◽  
Catalyst Poisoning ◽  
Benzylic Carbon ◽  
Alkyl Groups

The selective hydrogen exchange of alkyl groups of some alkylaromatic hydrocarbons and toluic acid derivatives was achieved by allowing these compounds to react with deuterium oxide over nickel on kieselguhr at 99�. The observed deuterium distributions and the results of catalyst poisoning experiments can be interpreted in terms of initial π-bonding of the substrates to the catalyst followed by dissociative adsorption at a benzylic carbon atom and transfer of adsorption through the alkyl group by an α-β process. Some nitro- and halo-toluenes underwent little or no exchange.

Effect of Alkyl Group Structure on Cure Characteristics of N,N-Dialkylthio-Carbamyl-N′,N′-Dialkylsulfenamide Vulcanization Accelerators

1974 ◽  
Vol 47 (4) ◽  
pp. 906-910 ◽  
Author(s):  
R. D. Taylor
Keyword(s):  
Carbon Atom ◽  
Steric Hindrance ◽  
Alkyl Group ◽  
Group Structure ◽  
Substituent Effects ◽  
Steric Effects ◽  
Alkyl Groups ◽  
Inductive Effects ◽  
Cure Rates ◽  
Alpha Carbon

Abstract Wide variations in scorch times and cure rates can be attained with tetraalkylthiocabamylsulfenamides through variation in alkyl groups. Substituent effects are substantial on either the carbamate nitrogen or on the sulfenamide nitrogen. Both inductive effects and steric effects influence the scorch times and cure rates. Positive inductive effects shorten scorch times and increase cure rates. Steric hindrance at the sulfenamide nitrogen increases the scorch time. Branching at the carbon atom beta to the nitrogen has a larger effect on scorch time than branching at the alpha carbon. Thiocarbamylsulfenamides can give appreciably higher cure rates and cure efficiencies than their benzothiazole sulfenamide analogs.

Catalytic deuterium exchange reactions with organics. XIII. Characteristic reactions of the Group VIII transition metals

1965 ◽  
Vol 18 (7) ◽  
pp. 1003 ◽  
Author(s):  
JL Garnett ◽  
WA Sollich
Keyword(s):  
Transition Metal ◽  
Hydrogen Exchange ◽  
Deuterium Oxide ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Group Viii ◽  
Exchange Reactions ◽  
Substitution Mechanism ◽  
Π Complex ◽  
Complex Adsorption

Activation procedures and hydrogen exchange reactions with six Group VIII transition metal catalysts (Pt, Pd, Ru, Rh, Ir, Ni) are reported for three characteristic reaction systems: (i) deuterium oxide/benzene, (ii) deuterium oxide/naphthalene, and (iii) deuterium oxide/n-octane. Results of these exchange reactions indicate that both π-complex adsorption and the dissociative π-complex substitution mechanism previously established for platinum are applicable to other Group VIII transition metal catalysts. For general catalytic labelling with isotopic hydrogen, platinum was found to be the most efficient of the catalysts investigated.

The Hantzsch pyrrole synthesis

1970 ◽  
Vol 48 (11) ◽  
pp. 1689-1697 ◽  
Author(s):  
M. W. Roomi ◽  
S. F. MacDonald
Keyword(s):  
Carboxylic Acids ◽  
Ethyl Acetoacetate ◽  
Alkyl Group ◽  
Ethyl Esters ◽  
Hantzsch Synthesis ◽  
Butyl Esters ◽  
Alkyl Groups

Ethyl esters of 2-alkyl- and 2,4-dialkylpyrrole-3-carboxylic acids are obtained generally by extensions of the Hantzsch synthesis, benzyl and t-butyl esters when the 2-alkyl group is methyl. Hemopyrrole is obtained from butanal and ethyl acetoacetate in three steps. Pyrroles bearing higher alkyl groups or carbobenzoxy groups are reductively alkylated like the corresponding methylpyrroles and carbethoxy derivatives; t-butyl esters do not survive.

scholarly journals Cytotoxicity against HL60 Cells of Ficifolidione Derivatives with Methyl, n-Pentyl, and n-Heptyl Groups

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4081
Author(s):  
Hisashi Nishiwaki ◽  
Megumi Ikari ◽  
Satomi Fujiwara ◽  
Kosuke Nishi ◽  
Takuya Sugahara ◽  
...  
Keyword(s):  
Insecticidal Activity ◽  
Alkyl Group ◽  
Caspase 3 ◽  
Biological Activities ◽  
Mosquito Larvae ◽  
Leukaemia Cell ◽  
Leukaemia Cell Line ◽  
Hl60 Cells ◽  
Flow Cytometric ◽  
Alkyl Groups

Ficifolidione, a natural insecticidal compound isolated from the essential oils of Myetaceae species, is a spiro phloroglucinol with an isobutyl group at the C-4 position. We found that ficifolidione showed cytotoxicity against cancer cells via apoptosis. Replacement of the isobutyl group by n-propyl group did not influence the potency, but the effect of the replacement of this group by a shorter or longer alkyl group on the biological activity remains unknown. In this study, ficifolidione derivatives with alkyl groups such as methyl, n-pentyl, and n-heptyl group—instead of the isobutyl group at the C-4 position—were synthesized to evaluate their cytotoxicity against the human promyelocytic leukaemia cell line HL60 and their insecticidal activity against mosquito larvae. The biological activities of their corresponding 4-epimers were also evaluated. As a result, the conversion of the isobutyl group to another alkyl group did not significantly influence the cytotoxicity or insecticidal activity. In HL60 cells treated with the n-heptyl-ficifolidione derivative, the activation of caspase 3/7 and the early stages of apoptosis were detected by using immunofluorescence and flow cytometric techniques, respectively, suggesting that the cytotoxicity should be induced by apoptosis even though the alkyl group was changed.

The Alkyl Inductive Effect, II Theoretical Calculation of Inductive Parameters

1979 ◽  
Vol 34 (2) ◽  
pp. 321-326 ◽  
Author(s):  
Harry F. Widingand ◽  
Leonard S. Levitt
Keyword(s):  
Electric Field ◽  
Alkyl Group ◽  
Bond Model ◽  
Chemical Effects ◽  
Alkyl Groups ◽  
Alkyl Substitution ◽  
Internal Induction ◽  
Experimental Values ◽  
Physical And Chemical ◽  
Calculated Distance

AbstractThree models of alkyl groups, “derealization”, “through-the-bond”, and “electric field” models, are presented, all of which enable the calculation of σI (R) from first principles, and excellent agreement is demonstrated for the calculated and experimental values of σI (R) . For the “delocalization” model it is found that - σI (R) = 0.0455 + 0.0232(1-1/n), where n is the number of C atoms in an n-alkyl group, and for an infinite C-chain R group, σI( R∞) is - 0.0687, identical to the value found b y a different method in Part I of this series. The “through-the-bond” model gives - σI(R) = - 0.0559 +, where Ci is the number of C-atoms in the i th position from X in RX; and for the “electric field” model, we obtain - σI(R) = 0.0463 + 0.0102 , where di is the calculated distance from C1 to Cn in the most probable conformation of the R-group. It is concluded that Taft's σI(R) values have a real significance whether or not the physical and chemical effects of alkyl substitution reside ultimately in an internal induction mechanism, or in alkyl group polarization by charged centers in the molecule, or a combination of the two.

Competitive pathways of methane activation on Zn2+-modified ZSM-5 zeolite: H/D hydrogen exchange with Brønsted acid sites versus dissociative adsorption to form Zn-methyl species

2016 ◽  
Vol 6 (16) ◽  
pp. 6381-6388 ◽  
Author(s):  
Sergei S. Arzumanov ◽  
Anton A. Gabrienko ◽  
Dieter Freude ◽  
Alexander G. Stepanov
Keyword(s):  
Hydrogen Exchange ◽  
Dissociative Adsorption ◽  
Acid Sites ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brønsted Acid Sites ◽  
Brönsted Acid ◽  
Brönsted Acid Sites ◽  
Bronsted Acid Sites ◽  
Zeolite P

Zn-methyl species is not responsible for facilitation of the H/D hydrogen exchange reaction of methane with Brønsted acid sites of Zn2+/H-ZSM-5 zeolite.

The Hydrolysis of Disubstituted Alkyl Phosphorochloridates and N,N,N′,N′-Tetra-stibstituted Phosphorodiamidic Chlorides in Water and Deuterium Oxide: Heat Capacity of Activation and Kinetic Solvent Isotope Effects

1973 ◽  
Vol 51 (4) ◽  
pp. 597-603 ◽  
Author(s):  
E. C. F. Ko ◽  
R. E. Robertson
Keyword(s):  
Heat Capacity ◽  
Thermodynamic Parameters ◽  
Alkyl Group ◽  
Deuterium Oxide ◽  
Isotope Effects ◽  
Potential Relationship ◽  
Mechanism Of Reaction ◽  
Solvent Isotope ◽  
Hydrolysis Of ◽  
Solvent Isotope Effects

The pseudo-thermodynamic parameters, ΔH≠, ΔS≠, and ΔCp≠ and the kinetic solvent isotope effects have been determined for the three alkyl-phosphorochloridates, where the alkyl group is ethylisopropyl and n-propyl; for tetra-methyl and tetra-ethyl phosphorodiamidic chlorides; the di-n-propyl and di-isopropyl analog, the di(isopropylmethylcarbinyl)phosphorochloridate and the tetra-ethylthiophosphorodiamidic chloride. These compounds have a potential relationship to compounds used as insecticides and as polymers. The mechanism of reaction is discussed on the basis of these data.

Organoplatinum(IV) complexes with functional alkyl groups and their use in supramolecular chemistry

2009 ◽  
Vol 87 (7) ◽  
pp. 904-916 ◽  
Author(s):  
Richard H.W. Au ◽  
Lisa J. Findlay-Shirras ◽  
Neil M. Woody ◽  
Michael C. Jennings ◽  
Richard J. Puddephatt
Keyword(s):  
Supramolecular Chemistry ◽  
Self Assembly ◽  
Alkyl Group ◽  
Oxidative Addition ◽  
Alkyl Groups ◽  
Alkyl Bromides ◽  
Diimine Ligand

The oxidative addition of alkyl bromides RCH2Br (R = C5H4N, C6H4CN, CH2C6H4CO2H, or CH2C6H4CH2CO2H) to dimethylplatinum(II) complexes [PtMe2(LL)] (LL = diimine ligand) gives the corresponding organoplatinum(IV) complexes [PtBrMe2(CH2R)(LL)] containing functionality in the alkyl group RCH2. The pyridyl derivatives can be protonated, while abstraction of the bromide ligand from [PtBrMe2(CH2R)(LL)] can form cationic complexes, which can react with water or form oligomers by self-assembly.

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