Solvents effects on aromatic nucleophilic substitutions. Part 5. Kinetics of the reactions of 1-fluoro-2,4-dinitrobenzene with piperidine in aprotic solvents
The kinetics of the reaction between 1-fluoro-2,4-dinitrobenzene and piperidine were studied in toluene, benzene, dioxane, trichloroethane, tetrahydrofuran, chlorobenzene, ethyl acetate, chloroform, dichloromethane, acetone, acetonitrile, and nitromethane. The second-order rate coefficient is almost...
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todo:paper_1472779X_v_n8_p951_Nudelman2023-10-03T16:18:07Z Solvents effects on aromatic nucleophilic substitutions. Part 5. Kinetics of the reactions of 1-fluoro-2,4-dinitrobenzene with piperidine in aprotic solvents Nudelman, N.S. Mancini, P.M.E. Martinez, R.D. Vottero, L.R. The kinetics of the reaction between 1-fluoro-2,4-dinitrobenzene and piperidine were studied in toluene, benzene, dioxane, trichloroethane, tetrahydrofuran, chlorobenzene, ethyl acetate, chloroform, dichloromethane, acetone, acetonitrile, and nitromethane. The second-order rate coefficient is almost insensitive to the amine concentration in chloroform, acetonitrile, and nitromethane; for the other solvents this value of k3/k2 is greater than 102, indicating neat base catalysis. The trend in k3/k2 does not follow the solvent basicity order; the solvents insensitive to base catalysis are those which exhibit hydrogen-bond donor (HBD) properties. These results are interpreted as an indication that in this reaction the detachment of the nucleofuge is the rate-limiting step in most of the aprotic solvents studied; those solvents which are H B D assist the departure of fluoride, and the formation of the intermediate is the rate-determining step. This conclusion was confirmed by kF/k Cl determinations. A simple linear energy solvation correlation was found between the parameter ET(30) and kA obtained at [B] < 10-2M. For higher amine contents increasing deviations were found. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_1472779X_v_n8_p951_Nudelman |
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Universidad de Buenos Aires |
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I-28 |
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R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| description |
The kinetics of the reaction between 1-fluoro-2,4-dinitrobenzene and piperidine were studied in toluene, benzene, dioxane, trichloroethane, tetrahydrofuran, chlorobenzene, ethyl acetate, chloroform, dichloromethane, acetone, acetonitrile, and nitromethane. The second-order rate coefficient is almost insensitive to the amine concentration in chloroform, acetonitrile, and nitromethane; for the other solvents this value of k3/k2 is greater than 102, indicating neat base catalysis. The trend in k3/k2 does not follow the solvent basicity order; the solvents insensitive to base catalysis are those which exhibit hydrogen-bond donor (HBD) properties. These results are interpreted as an indication that in this reaction the detachment of the nucleofuge is the rate-limiting step in most of the aprotic solvents studied; those solvents which are H B D assist the departure of fluoride, and the formation of the intermediate is the rate-determining step. This conclusion was confirmed by kF/k Cl determinations. A simple linear energy solvation correlation was found between the parameter ET(30) and kA obtained at [B] < 10-2M. For higher amine contents increasing deviations were found. |
| format |
JOUR |
| author |
Nudelman, N.S. Mancini, P.M.E. Martinez, R.D. Vottero, L.R. |
| spellingShingle |
Nudelman, N.S. Mancini, P.M.E. Martinez, R.D. Vottero, L.R. Solvents effects on aromatic nucleophilic substitutions. Part 5. Kinetics of the reactions of 1-fluoro-2,4-dinitrobenzene with piperidine in aprotic solvents |
| author_facet |
Nudelman, N.S. Mancini, P.M.E. Martinez, R.D. Vottero, L.R. |
| author_sort |
Nudelman, N.S. |
| title |
Solvents effects on aromatic nucleophilic substitutions. Part 5. Kinetics of the reactions of 1-fluoro-2,4-dinitrobenzene with piperidine in aprotic solvents |
| title_short |
Solvents effects on aromatic nucleophilic substitutions. Part 5. Kinetics of the reactions of 1-fluoro-2,4-dinitrobenzene with piperidine in aprotic solvents |
| title_full |
Solvents effects on aromatic nucleophilic substitutions. Part 5. Kinetics of the reactions of 1-fluoro-2,4-dinitrobenzene with piperidine in aprotic solvents |
| title_fullStr |
Solvents effects on aromatic nucleophilic substitutions. Part 5. Kinetics of the reactions of 1-fluoro-2,4-dinitrobenzene with piperidine in aprotic solvents |
| title_full_unstemmed |
Solvents effects on aromatic nucleophilic substitutions. Part 5. Kinetics of the reactions of 1-fluoro-2,4-dinitrobenzene with piperidine in aprotic solvents |
| title_sort |
solvents effects on aromatic nucleophilic substitutions. part 5. kinetics of the reactions of 1-fluoro-2,4-dinitrobenzene with piperidine in aprotic solvents |
| url |
http://hdl.handle.net/20.500.12110/paper_1472779X_v_n8_p951_Nudelman |
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