Kinetics and Mechanism of the Aminolysis of Thiophenyl Acetates in Acetonitrile

Title
Kinetics and Mechanism of the Aminolysis of Thiophenyl Acetates in Acetonitrile
Authors
Lee, HW.
Keywords
REACTIVITY-SELECTIVITY PRINCIPLE, CONCERTED MECHANISM
Issue Date
1999-12
Publisher
KOREAN CHEMICAL SOC
Abstract
Kinetics and mechanism of the aminolysis of Z-thiophenyl acetates with X-benzylamines are investigated in acetonitrile at 45.0 degrees C. The magnitudes of Bronsted coefficients beta(x) (=1.3 similar to-1.6) and beta(z)(= -2. 1 similar to-2.4) are all large and cross-interaction constant rho(xz) is relatively large and positive (0.90. These trends are consistent with the rate-limiting breakdown of a tetrahedral intermediate, T+/-. The proposed mechanism is also supported by adherence of the rate data to the reactivity-selectivity principle (RSP). The kinetic isotope effects, k(H)/k(D), are greater than unity (1.3-1.4) suggesting a possibility of hydrogen-bonded four-centered transition state. The activation parameters, Delta H-not equal and Delta S-not equal, are consistent with this transition-state structure.
URI
http://dspace.inha.ac.kr/handle/10505/20363
ISSN
0253-2964
Appears in Collections:
College of Natural Science(자연과학대학) > Chemistry (화학) > Journal Papers, Reports(화학 논문, 보고서)
Files in This Item:
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