Mechanisms of Nucleophilic Attack at Carbon - Nitrogen Double Bonds: Reactions of Benzohydrazonoyl Halides with Secondary Amines in Benzene

1997 ◽  
Vol 50 (8) ◽  
pp. 849 ◽  
Author(s):  
Jeffrey E. Rowe ◽  
Kam Lee
Keyword(s):  
Second Order ◽  
Secondary Amines ◽  
Nucleophilic Attack ◽  
Rate Equations ◽  
Rate Data ◽  
Double Bonds ◽  
Effect Data ◽  
First Order ◽  
Amine Molecule

The reactions of a series of substituted benzohydrazonoyl halides with cyclic secondary amines in benzene as solvent are investigated. The rate equations for these reactions were complex and the derived rate data are reported. The element effect data showed that the fluoro compounds only reacted when a second amine molecule was available to assist the reaction, whereas the chloro and bromo compounds reacted by reactions which were both first order and second order in amine (k′′Br : k′′Cl = 9·5 : 1 and k′′′Br :k′′′Cl : k′′′F = 4·7 : 1 : 0·65). The mechanism of these reactions is discussed.

Mechanisms of Nucleophilic Attack at Carbon Nitrogen Double-Bonds: The Reaction of Benzohydrazonoyl Halides With Amines

1987 ◽  
Vol 40 (10) ◽  
pp. 1777 ◽  
Author(s):  
AF Hegarty ◽  
P Rigopoulos ◽  
JE Rowe
Keyword(s):  
Double Bond ◽  
Nucleophilic Attack ◽  
Rate Data ◽  
Double Bonds ◽  
Nitrogen Double Bond

Rate data for the reaction of a series of benzohydrazonoyl halides with pyrrolidine and butan- 1-amine at 303 K are presented. Linear Hammett plots were obtained with each amine. The mechanism of the reactions and the stereochemical outcome of these displacements at the carbon-nitrogen double bond are discussed.

Mechanisms of Nucleophilic Attack at Carbon-Nitrogen Double Bonds. The Reaction of Benzohydrazonoyl Compounds With Methoxide Ion

1995 ◽  
Vol 48 (12) ◽  
pp. 2041 ◽  
Author(s):  
JE Rowe ◽  
DA Papanelopoulos
Keyword(s):  
Nucleophilic Attack ◽  
Rate Data ◽  
Double Bonds ◽  
Elimination Mechanism ◽  
Methoxide Ion

Rate data for the reaction of a number of benzohydrazonoyl compounds with methoxide ion are reported. The stereochemistry of the products was determined by h.p.l.c. The mechanism of the reactions and the stereochemistry of the products resulting from an addition-elimination mechanism are discussed.

scholarly journals Integrated rate equations for enzyme-catalysed first-order and second-order reactions

1984 ◽  
Vol 223 (1) ◽  
pp. 15-22 ◽  
Author(s):  
E A Boeker
Keyword(s):  
Initial Rate ◽  
Second Order ◽  
Rate Equations ◽  
First Order ◽  
Rate Kinetics

Generalized rate equations covering all mechanisms giving hyperbolic initial-rate kinetics with stoichiometry A in equilibrium P, A in equilibrium P + Q, A + B in equilibrium P and A + B in equilibrium P + Q were integrated. The results are regular and reasonably economical.

Nucleophilic attack on the carbon–carbon double bond. I. Reaction of primary and secondary amines with 2,2-di(4-nitrophenyl)-1,1-difluoroethene

1986 ◽  
Vol 64 (12) ◽  
pp. 2274-2278 ◽  
Author(s):  
Kenneth T. Leffek ◽  
Urszula Maciejewska
Keyword(s):  
Order Reaction ◽  
Secondary Amines ◽  
Nucleophilic Attack ◽  
Ammonium Ions ◽  
Third Order ◽  
First Order ◽  
Enthalpy Of Activation ◽  
Catalysed Reaction ◽  
Primary And Secondary Amines ◽  
Reaction Proceeds

The reaction of primary and secondary amines with 2,2-di(4-nitrophenyl)-1,1-difluoroethene (1) in acetonitrile solvent gives first 2,2-di(4-nitrophenyl)-1-fluoro-1-aminoethene (2) and then 2,2-di(4-nitrophenyl)-1,1-difluoro-1-aminoethane (3). With excess amine, pseudo-first-order rate constants for the production of 2 were measured, which showed a second-order reaction, together with a catalysed third-order reaction. In addition to the reagent amines, the reaction is also catalysed by tertiary amines and bases such as oxalate and acetate, but not by chloride and perchlorate, nor by ammonium ions. The enthalpy of activation for the reaction of piperidine with 1 in acetonitrile is 3.7 kcalmol−1, but for the catalysed reaction an apparent value of −2.2 kcal mol−1 was obtained. It is concluded that the reaction proceeds via a pre-equilibrium to a zwitterion, followed by another equilibrium giving a carbanion that yields the product (2) by a rate-determining cleavage of the carbon–fluorine bond.

Mechanisms of Nucleophilic Attack at Carbon-Nitrogen Double Bonds. The Solvolysis of Substituted Benzohydrazonoyl Halides in Aqueous Binary Mixtures

1991 ◽  
Vol 44 (3) ◽  
pp. 463 ◽  
Author(s):  
JE Rowe
Keyword(s):  
Binary Mixtures ◽  
Aqueous Ethanol ◽  
Nucleophilic Attack ◽  
Rate Data ◽  
Double Bonds ◽  
Aqueous Binary Mixtures ◽  
Mechanism Of The Reaction

Rate data for the solvolysis of a series of substituted benzohydrazonoyl halides in aqueous dioxan at 329 K and in aqueous ethanol and methanol at 303 K are presented. The products in the aqueous alcohols were measured by h.p.l.c ., and the selectivities determined. The data are used to support proposals about the mechanism of the reaction.

Benzenesulfonyl chloride with primary and secondary amines in aqueous media — Unexpected high conversions to sulfonamides at high pH

2005 ◽  
Vol 83 (9) ◽  
pp. 1525-1535 ◽  
Author(s):  
James F King ◽  
Manjinder S Gill ◽  
Petru Ciubotaru
Keyword(s):  
Sodium Hydroxide ◽  
Sulfonyl Chloride ◽  
Second Order ◽  
Secondary Amines ◽  
Third Order ◽  
Benzenesulfonyl Chloride ◽  
Aqueous Sodium ◽  
First Order ◽  
The Third ◽  
Primary And Secondary Amines

We have determined pH–yield profiles under pseudo-first-order conditions of the reactions of benzenesulfonyl chloride with a set of primary and secondary water-soluble alkylamines, and have found with certain amines, such as dibutylamine, a profile taking the form of a sigmoid pH&#150yield curve with relatively high yields of the sulfonamide persisting with increasing basicity up to and including 1.0 mol/L sodium hydroxide. This behaviour is quantitatively accounted for by invoking, in addition to the usual second-order reaction of the sulfonyl chloride with the amine, two third-order terms (i) one first-order in sulfonyl chloride, amine and hydroxide anion, and (ii) another first-order in sulfonyl chloride and second-order in the amine. The importance of the third-order terms correlates approximately with the total number of alkyl carbon atoms in the amine, and this in turn is regarded as related to the hydrophobic character of the amine. Experiments to test this picture included: (i) observation of a bell-shaped curve with bis(2-methoxyethyl)amine, (ii) in the reaction of dibutylamine in THF&#150H2O (1:1), and also (iii) in the reaction of dibutylamine in 1.0 mol/L tetrabutylammonium bromide, and (iv) increase in the contributions of the third-order terms in 1.0 mol/L aqueous sodium chloride. Preparative reactions with dibutylamine, 1-octylamine, and hexamethylenimine in 1.0 mol/L aqueous sodium hydroxide with a 5% excess of benzenesulfonyl chloride gave, respectively, 94%, 98%, and 97% yields of the corresponding sulfonamides. Key words: sulfonyl chlorides, primary and secondary amines, pH–yield profiles, organic synthesis in water, hydrophobic effects.

The aminolysis of phosphinates; the kinetics and mechanism of the aminolysis of phosphinate esters in acetonitrile

1986 ◽  
Vol 64 (2) ◽  
pp. 213-219 ◽  
Author(s):  
Robert D. Cook ◽  
Wafa A. Daouk ◽  
Asaad N. Hajj ◽  
Ahmad Kabbani ◽  
Anwar Kurku ◽  
...  
Keyword(s):  
Solvent Effects ◽  
Activation Parameters ◽  
Second Order ◽  
The Other ◽  
Secondary Amines ◽  
Rate Law ◽  
First Order ◽  
General Base ◽  
Leaving Group ◽  
Reactivity Order

The aminolysis of aryl diphenylphosphinates, p-nitrophenyl diphenylphosphinothionate, -phosphinothioate, and -phosphinodithioate by n-butylamine, by the secondary amines piperidine, pyrrolidine, morpholine, and dipropylamine, as well as by a series of diamines, has been studied in acetonitrile. The general reactivity order is diamines > butylamine > sec-amines. Butylaminolysis follows a two-term rate law, one first order in amine and the other second order in amine. The second order in amine term predominates. sec-Amines and diamines follow a rate law which is first order in amine only. Leaving group effects, solvent effects, and activation parameters support a pathway which involves rate-determining collapse of a zwitterionic pentacoordinate intermediate. In the case of butylamine this collapse is general base catalyzed and for the diamines the reaction is intramolecularly general base catalyzed.

scholarly journals Integrated rate equations for irreversible enzyme-catalysed first-order and second-order reactions

1985 ◽  
Vol 226 (1) ◽  
pp. 29-35 ◽  
Author(s):  
E A Boeker
Keyword(s):  
Second Order ◽  
Rate Equations ◽  
Detailed Mechanism ◽  
First Order ◽  
Mechanism Of The Reaction

Integrated rate equations are presented that describe irreversible enzyme-catalysed first-order and second-order reactions. The equations are independent of the detailed mechanism of the reaction, requiring only that it be hyperbolic and unbranched. The results should be directly applicable in the laboratory.

Mechanisms of nucleophilic attack at carbon-nitrogen double bonds. The reaction of aryl N-arylbenzimidates with methoxide ion

1983 ◽  
Vol 36 (6) ◽  
pp. 1259 ◽  
Author(s):  
JE Rowe
Keyword(s):  
Isotope Effects ◽  
Nucleophilic Attack ◽  
Rate Data ◽  
Double Bonds ◽  
Tetrahedral Intermediate ◽  
Methoxide Ion ◽  
Solvent Isotope ◽  
Solvent Isotope Effects

Rate data for the reaction of three series of aryl N-arylbenzimidates with methoxide ion at 303 K are presented. Linear Hammett plots were obtained for each series. Solvent isotope effects have also been measured. The results are interpreted in terms of rate-determining formation of a tetrahedral intermediate, irrespective of the nature of the substituent.

Sign in / Sign up

Export Citation Format

Share Document