Experimental method for estimating substituent effects on transition-state structure

1971 ◽  
Vol 93 (8) ◽  
pp. 2091-2093 ◽  
Author(s):  
Paul Haberfield
Keyword(s):  
Transition State ◽  
Experimental Method ◽  
Substituent Effects ◽  
State Structure ◽  
Transition State Structure

Isotope effects in nucleophilic substitution reactions X. The effect of changing the nucleophilic atom on ion-pairing in an SN2 reaction

1998 ◽  
Vol 76 (6) ◽  
pp. 758-764 ◽  
Author(s):  
Yao-ren Fang ◽  
Zhu-gen Lai ◽  
Kenneth Charles Westaway
Keyword(s):  
Transition State ◽  
Nucleophilic Substitution ◽  
Isotope Effect ◽  
Kinetic Isotope Effect ◽  
Isotope Effects ◽  
Substituent Effects ◽  
Ion Pairing ◽  
State Structure ◽  
Transition State Structure ◽  
Kinetic Isotope

The effect of ion-pairing in an SN2 reaction is very different when the nucleophilic atom is changed from sulfur to oxygen, i.e., changing the nucleophile from thiophenoxide ion to phenoxide ion. When the nucleophile is sodium thiophenoxide, ion-pairing markedly alters the secondary α -deuterium kinetic isotope effect (transition state structure) and the substituent effect found by changing the para substituent on the nucleophile. When the nucleophile is sodium phenoxide, ion-pairing does not significantly affect the secondary α -deuterium or the chlorine leaving group kinetic isotope effects (transition state structure) or the substituent effects found by changing a para substituent on the nucleophile or the substrate. The different effects of ion-pairing may occur because the electron density on the hard oxygen atom of the sodium phenoxide is not affected significantly by ion-pairing.Key words: nucleophilic substitution, SN2, kinetic isotope effect, transition state, substituent effects, ion-pair.

Rearrangement of chorismate to prephenate. Use of chorismate mutase inhibitors to define the transition state structure

Biochemistry ◽  
1977 ◽  
Vol 16 (22) ◽  
pp. 4848-4852 ◽  
Author(s):  
P. R. Andrews ◽  
E. N. Cain ◽  
E. Rizzardo ◽  
G. D. Smith
Keyword(s):  
Transition State ◽  
Chorismate Mutase ◽  
State Structure ◽  
Transition State Structure

Conservation of Transition State Structure in Fast Folding Peripheral Subunit-Binding Domains

2008 ◽  
Vol 383 (1) ◽  
pp. 224-237 ◽  
Author(s):  
Timothy D. Sharpe ◽  
Neil Ferguson ◽  
Christopher M. Johnson ◽  
Alan R. Fersht
Keyword(s):  
Transition State ◽  
State Structure ◽  
Transition State Structure ◽  
Binding Domains
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