Competitive reaction pathways in the nucleophilic substitution reactions of aryl benzenesulfonates with benzylamines in acetonitrile

Jin Heui Choi; Byung Choon Lee; Hai Whang Lee; Ikchoon Lee

doi:10.1021/jo0161835

Competitive reaction pathways in the nucleophilic substitution reactions of aryl benzenesulfonates with benzylamines in acetonitrile

J Org Chem. 2002 Feb 22;67(4):1277-81. doi: 10.1021/jo0161835.

Authors

Jin Heui Choi¹, Byung Choon Lee, Hai Whang Lee, Ikchoon Lee

Affiliation

¹ Department of Chemistry, Choongbuk National University, Chongju 360-763, Korea.

PMID: 11846674
DOI: 10.1021/jo0161835

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.