245. Condensations of carbonyl compounds. A kinetic study of the reaction of acetophenone with benzaldehyde

1940 ◽  
pp. 1295 ◽  
Author(s):  
Elizabeth Coombs ◽  
David P. Evans
Keyword(s):  
Kinetic Study ◽  
Carbonyl Compounds

Réactions d'addition nucléophiles sur les cétones. Mise en évidence d'un effet directionnel d'origine stérique dans l'effet isotopique secondaire du deutérium

1980 ◽  
Vol 58 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Bernard Boyer ◽  
Gérard Lamaty ◽  
Jean-Pierre Roque ◽  
Patrick Geneste
Keyword(s):  
Kinetic Study ◽  
Isotope Effect ◽  
Carbonyl Compounds ◽  
Isotope Effects ◽  
Reaction Process ◽  
Addition Reactions ◽  
Deuterium Isotope Effect ◽  
Directional Effect ◽  
Sulfite Ions ◽  
Process Journal

A kinetic study of the addition reactions of borohydride and sulfite ions and of hydroxylamine to a number of stereospecifically deuterated carbonyl compounds (3,3,5,5-tetramethyl cyclohexanone, 7,7-d2-bicyclo[2,2,1]-2-bornanone) leads to the observation of a distant secondary deuterium isotope effect. The results obtained reveal the intervention of a directional effect in the steric origin of these isotope effects. In particular, this study shows the importance of the orientation of the vibrations brought into play by a C—D bond during the reaction process. (Journal translation)

scholarly journals Kinetic Study on Induced Electron Transfer Reaction in Pentaamminecobalt(III) Complexes of α-Hydroxy Acids by Pyridinium Fluorochromate in Micellar Medium

2011 ◽  
Vol 8 (3) ◽  
pp. 1102-1107
Author(s):  
B. Mohammed Nawaz ◽  
K. Subramani ◽  
Mansur Ahmed
Keyword(s):  
Electron Transfer ◽  
Kinetic Study ◽  
Carbonyl Compounds ◽  
Transfer Reaction ◽  
Electron Transfer Reaction ◽  
Micellar Medium ◽  
Hydroxy Acids ◽  
Uv Visible ◽  
Pyridinium Fluorochromate

Pyridinium fluorochromate (PFC) oxidation of pentaamminecobalt(III) complexes of α-hydroxy acids in micellar medium yielding nearly 100% of carbonyl compounds are ultimate products. The decrease in UV-visible absorbance at λ=502 nm for Co(III) complex corresponds to nearly 100% of the initial absorbance. The stoichiometry of unbound ligand and cobalt(III) complex is accounting for about 100% reduction at the cobalt(III) centre. The kinetic and stoichiometric results have been accounted by a suitable mechanism.

THE CHEMISTRY OF YLIDS: XV. MECHANISM OF THE REACTION OF IMINOPHOSPHORANES WITH CARBONYL COMPOUNDS

1966 ◽  
Vol 44 (23) ◽  
pp. 2793-2803 ◽  
Author(s):  
A. William Johnson ◽  
Simon C. K. Wong
Keyword(s):  
Nitrogen Atom ◽  
Kinetic Study ◽  
Phosphorus Atom ◽  
Carbonyl Compounds ◽  
Delicate Balance ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Rate Limiting ◽  
Mechanism Of The Reaction

The pKa values of two series of iminophosphoranes, N-(substituted phenyl)-iminotriphenylphosphoranes (VI) and N-phenyliminotri-(substituted phenyl)-phosphoranes (VII), have been correlated with σ0 and σ, respectively, giving ρ values of +3.5 and +9.3. A kinetic study of the reaction of VI and VII with benzaldehydes indicates that a betaine intermediate (V) is involved. The rate-limiting step of the reaction changes, the result of a delicate balance between the nucleophilicity of the nitrogen atom and the electrophilicity of the phosphorus atom. The involvement of dπ–pπ bonding is indicated.

A kinetic study of controlling nitrogen in process for boron steel by using30N2isotope gas

2008 ◽  
Vol 105 (12) ◽  
pp. 601-608
Author(s):  
Seung Min Han ◽  
Dong Joon Min ◽  
Joo Hyun Park ◽  
Jung Ho Park ◽  
Jong Min Park
Keyword(s):  
Kinetic Study ◽  
Boron Steel

Kinetic Study of the Effect of Heparin on the Amidase Activity of Trypsin, Plasmin and Urokinase

1983 ◽  
Vol 49 (03) ◽  
pp. 199-203 ◽  
Author(s):  
V M Yomtova ◽  
N A Stambolieva ◽  
B M Blagoev
Keyword(s):  
Kinetic Study ◽  
Active Center ◽  
Simultaneous Presence ◽  
Amidase Activity ◽  
Competitive Inhibitors ◽  
Uncompetitive Inhibitor

SummaryIt was found that the effect of heparin on the amidase activity of urokinase (E C 3.4.21.31), plasmin (E C 3.4.21.7) and trypsin (E C 3.4.21.4) depended on the substrate used. No effect of heparin on the amidase activity of urokinase and trypsin was observed when Pyro Glu-Gly-Arg-p-nitroanilide (S-2444) and α-N-acetyl-L-lysine-p-nitroanilide (ALNA) were used as substrates. Heparin acted as a uncompetitive inhibitor of trypsin (Ki = 1.2×10-6 M), plasmin (Ki = 4.9×10-6 M) and urokinase (Ki = l.0×10-7 M) when Bz-Phe-Val-Arg-p-nitroanilide (S-2160), H-D-Val-Leu-Lys-p-nitroanilide (S-2251) and plasminogen, respectively, were used as substrates. These results, as well as the data obtained by studying the effect of the simultaneous presence of heparin and competitive inhibitors suggest that although heparin is not bound at the active center of these enzymes, it may influence the effectivity of catalysis.

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