Kinetic studies of bold σ -adduct formation and nucleophilic substitution in the reactions of ethyl 2,4,6-trinitrophenyl ether, some phenyl 2,4,6-trinitrophenyl ethers, and phenyl 2,4-dinitronaphthyl ether with aniline in dimethyl sulfoxide
作者:Michael R Crampton、Ian A Robotham
DOI:10.1139/v97-225
日期:1998.6.1
The reaction of ethyl 2,4,6-trinitrophenyl ether with aniline in dimethylsulfoxide containing Dabco occurs in two stages. The first gives 5, the σ -adduct intermediate on the substitution pathway, which has been identified spectroscopically. The second yields 2,4,6-trinitrodiphenylamine, the substitution product. Kinetic studies show that proton transfer is rate limiting both in the formation of the
Kharaba, Mohamed A. H.; Nassar, Ahmad M. G.; Youssef, Abdel-Hamid A., Polish Journal of Chemistry, 1991, vol. 65, # 5-6, p. 1029 - 1034
作者:Kharaba, Mohamed A. H.、Nassar, Ahmad M. G.、Youssef, Abdel-Hamid A.、Faid-Allah, Hassan M.
DOI:——
日期:——
Kinetic and equilibrium studies of ?-adduct formation and nucleophilic substitution in the reactions of morpholine with 1,3,5-trinitrobenzene and some phenyl aryl ethers in dimethyl sulphoxide
作者:Rachel A. Chamberlin、Michael R. Crampton、Ian A. Robotham
Reactions of morpholine in dimethyl sulphoxide at unsubstituted ring positions of 1,3,5-trinitrobenzene, and phenyl 2,4,6-trinitrophenyl ether, yield anionic sigma-adducts via zwitterionic intermediates. Reactions at the 1-position of phenyl 2,4,6-trinitrophenyl ether, phenyl 2,4-dinitronaphthyl ether, and phenyl 2,4-dinitrophenyl ether result in substitution of the phenoxy groups. In both these reaction types proton-transfer is rate-limiting. Comparison of kinetic and equilibrium data with those for corresponding reactions of piperidine shows that rate constants for proton transfer are similar for the two amines, but equilibrium constants for zwitterion formation have lower values for morpholine, the less basic amine. Implications for base catalysis are discussed.