An unprecedented concerted pathway in the alkaline hydrolysis of S-aryl thioesters.
[reaction: see text] Kinetic data indicate that the hydrolysis of S-2,4-dinitrophenyl 4'-hydroxythiobenzoate in mild alkaline solutions (pH 8-11) most likely follows a dissociative, E1cB pathway, through a p-oxoketene intermediate, whereas at higher pH values an associative mechanism carries the reaction flux. Free linear energy relationships obtained from a kinetic study on the alkaline hydrolyses of substituted S-aryl 4'-hydroxythiobenzoates seem to suggest that the associative pathway is a concerted, one-step process, rather than the classical mechanism via a tetrahedral intermediate.
Cevasco
Giorgio
G
Consiglio Nazionale delle Ricerche and Dipartimento di Chimica e Chimica Industriale dell'Università di Genova, Via Dodecaneso, 31, 16146 Genova, Italy. giocev@chimica.unige.it
Thea
Sergio
S