title: Competitive reaction pathways in the nucleophilic substitution reactions of aryl benzenesulfonates with benzylamines in acetonitrile.
abstract: The reactions of aryl benzenesulfonates (YC6H4SO2OC6H4Z) with benzylamines (XC6H4CH2NH2) in acetonitrile at 65.0 degrees C have been studied. The reactions proceed competitively by S-O (kS-O) and C-O (kC-O) bond scission, but the former provides the major reaction pathway. On the basis of analyses of the Hammett and Brönsted coefficients together with the cross-interaction constants rho(XY), rho(YZ), and rho(XZ), stepwise mechanisms are proposed in which the S-O bond cleavage proceeds by rate-limiting formation of a trigonal-bipyramidal pentacoordinate (TBP-5C) intermediate, whereas the C-O bond scission takes place by rate-limiting expulsion of the sulfonate anion (YC6H4SO3-) from a Meisenheimer-type complex.
authors.affiliation: Department of Chemistry, Choongbuk National University, Chongju 360-763, Korea.
authors.forename: Jin Heui
authors.initials: JH
authors.lastname: Choi
authors.forename: Byung Choon
authors.initials: BC
authors.lastname: Lee
authors.forename: Hai Whang
authors.initials: HW
authors.lastname: Lee
authors.forename: Ikchoon
authors.initials: I
authors.lastname: Lee