Aminolysis and pyridinolysis ofO-arylS-(4-nitrophenyl) thiocarbonates in aqueous ethanol. Kinetics and mechanism

2008 ◽  
Vol 21 (4) ◽  
pp. 271-278 ◽  
Author(s):  
Enrique A. Castro ◽  
Margarita Aliaga ◽  
José G. Santos
Keyword(s):  
Aqueous Ethanol ◽  
Kinetics And Mechanism ◽  
Ethanol Kinetics

Reactions of O -aryl S -aryl dithiocarbonates with pyridines in aqueous ethanol: kinetics and mechanism

2009 ◽  
Vol 22 (10) ◽  
pp. 1003-1008 ◽  
Author(s):  
Enrique A. Castro ◽  
Marcela Gazitúa ◽  
José G. Santos
Keyword(s):  
Aqueous Ethanol ◽  
Kinetics And Mechanism ◽  
Ethanol Kinetics

Kinetics and Mechanism of the Anilinolysis of Aryl 4-Nitrophenyl Carbonates in Aqueous Ethanol

2005 ◽  
Vol 70 (20) ◽  
pp. 8088-8092 ◽  
Author(s):  
Enrique A. Castro ◽  
Marcela Gazitúa ◽  
José G. Santos
Keyword(s):  
Aqueous Ethanol ◽  
Kinetics And Mechanism

Kinetics and mechanism of the aminolysis of 4-nitrophenyl and 2,4-dinitrophenyl 4-methylphenyl carbonates in aqueous ethanol

2002 ◽  
Vol 34 (5) ◽  
pp. 309-315 ◽  
Author(s):  
Enrique A. Castro ◽  
Monica Andujar ◽  
Paola Campodonico ◽  
Jos� G. Santos
Keyword(s):  
Aqueous Ethanol ◽  
Kinetics And Mechanism

Kinetics and Mechanism of the Pyridinolysis ofS-4-Nitrophenyl 4-Substituted Thiobenzoates in Aqueous Ethanol

2004 ◽  
Vol 69 (16) ◽  
pp. 5399-5404 ◽  
Author(s):  
Enrique A. Castro ◽  
Melissa Vivanco ◽  
Raul Aguayo ◽  
José G. Santos
Keyword(s):  
Aqueous Ethanol ◽  
Kinetics And Mechanism

Kinetics and mechanism of the aminolysis of thioesters and thiocarbonates in solution

2009 ◽  
Vol 81 (4) ◽  
pp. 685-696 ◽  
Author(s):  
Enrique A. Castro
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Rate Constant ◽  
Aqueous Ethanol ◽  
Kinetics And Mechanism ◽  
Kinetic Investigation ◽  
Concerted Mechanism ◽  
Tetrahedral Intermediate ◽  
Leaving Group ◽  
The Stability

The aminolysis reactions of thioesters and thiocarbonates, in either aqueous solution or in 44 wt % aqueous ethanol at 25 °C, are subjected to a kinetic investigation. The Brønsted-type plots (lg kN vs. amine pKa, where kN is the nucleophilic rate constant) obtained for these reactions can be grouped in three categories: linear plots with slopes 0.8-1, biphasic plots (two linear portions and a curve in between), and linear plots with slopes 0.4-0.6. The two former plots are attributed to stepwise reactions through a zwitterionic tetrahedral intermediate. The latter plots are associated with a concerted mechanism. The fact that some reactions are stepwise and others concerted depends on the stability of the zwitterionic tetrahedral intermediate. This work shows how the experimental data allows one to assess the mechanism of these reactions. Also discussed are the factors that affect the stability of this intermediate, which in turn determines the pathway followed by the reaction. The factors analyzed in this work are (i) the leaving group of the substrate, (ii) the nature of the amine, (iii) the non-leaving group of the substrate, (iv) the electrophilic group of the substrate (CS vs. CO), and (v) the solvent.

Kinetics and mechanism of the aminolysis ofO-ethylS-phenyl dithiocarbonate in aqueous ethanol

1995 ◽  
Vol 27 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Enrique A. Castro ◽  
Mauricio Cabrera ◽  
Jose G. Santos
Keyword(s):  
Aqueous Ethanol ◽  
Kinetics And Mechanism
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