5292-87-5Relevant academic research and scientific papers
Nucleofugality hierarchy, in the aminolysis reaction of 4-cyanophenyl 4-nitrophenyl carbonate and thionocarbonate. Experimental and theoretical study
Aliaga, Margarita E.,Cornejo, Patricio,Montecinos, Rodrigo,Pavez, Paulina,Santos, José G.
, p. 11495 - 11505 (2021/07/12)
Nucleophilic substitution reactions of the title compounds have been investigated with a series of secondary alicyclic amines in several solvents. The solvent, amine, and electrophilic group effects on kinetics, mechanism and nucleofugality hierarchy are discussed from experimental and theoretical studies. These studies show the mechanistic dependence on the solvent polarity; the theoretical results indicate that the relative polarization of the reactive centres (CO and CS) and the stabilization of the nucleofuges are the main factors in the control of the product distribution.
Structure-Reactivity Correlations in the Aminolysis and Pyridinolysis of Bis(phenyl) and Bis(4-nitrophenyl) Thionocarbonates
Castro, Enrique A.,Santos, Jose G.,Tellez, Jimena,Umana, Maria I.
, p. 6568 - 6574 (2007/10/03)
The reactions of a series of secondary alicyclic amines with bis(phenyl) and bis(4-nitrophenyl) thionocarbonates (BPTOC and BNPTOC, respectively), and a series of pyridines with the latter substrate, are subjected to a kinetic investigation in water, 25.0
Kinetics and Mechanism of the Aminolysis of Phenyl and 4-Nitrophenyl Chlorothionoformates
Castro, Enrique A.,Cubillos, Maria,Santos, Jose G.
, p. 4395 - 4397 (2007/10/03)
The reactions of a series of secondary alicyclic amines with the title substrates are subjected to a kinetic investigation in aqueous solution, 25 °C, ionic strength 0.2 M (maintained with KCl). Under amine excess pseudo-first-order rate coefficients (kobsd) are found. The plots of kobsd against concentration of free amine at constant pH are linear, with the slopes (kN) independent of pH. The Broensted-type plots obtained (log kN vs amine pKa) for the aminolysis of both substrates are linear with the same slope, β = 0.26. From this value, the kinetic law, and the analysis of products, it is deduced that these reactions proceed through a zwitterionic tetrahedral addition intermediate (T±) on the reaction path, and its formation is the rate-determining step. From a comparison of the present reactions with the concerted aminolysis of substituted phenyl chloroformates in acetonitrile it is inferred that the change of S- by O- in T± and that of water by acetonitrile as solvent destabilizes T± in such a way that the stepwise reaction becomes enforced concerted.
