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...
Guardado en:
Autores principales: | , , , |
---|---|
Formato: | JOUR |
Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_1472779X_v_n8_p951_Nudelman |
Aporte de: |
id |
todo:paper_1472779X_v_n8_p951_Nudelman |
---|---|
record_format |
dspace |
spelling |
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 |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
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 |
work_keys_str_mv |
AT nudelmanns solventseffectsonaromaticnucleophilicsubstitutionspart5kineticsofthereactionsof1fluoro24dinitrobenzenewithpiperidineinaproticsolvents AT mancinipme solventseffectsonaromaticnucleophilicsubstitutionspart5kineticsofthereactionsof1fluoro24dinitrobenzenewithpiperidineinaproticsolvents AT martinezrd solventseffectsonaromaticnucleophilicsubstitutionspart5kineticsofthereactionsof1fluoro24dinitrobenzenewithpiperidineinaproticsolvents AT votterolr solventseffectsonaromaticnucleophilicsubstitutionspart5kineticsofthereactionsof1fluoro24dinitrobenzenewithpiperidineinaproticsolvents |
_version_ |
1782028201306882048 |