title: Nucleophilic reactivities of benzenesulfonyl-substituted carbanions.
abstract: Kinetics of the reactions of four benzenesulfonyl-stabilized carbanions (1a-d)- with reference electrophiles (quinone methides 2 and diarylcarbenium ions 3) have been determined in dimethyl sulfoxide solution at 20 degrees C in order to derive the reactivity parameters N and s according to the linear free-energy relationship logk(20 degrees C) = s(N + E) (eqn (1)). The additions of (1a-d)- to ordinary Michael acceptors (e.g., benzylidene Meldrum's acid 4a, benzylidenebarbituric acids 5a-c, and benzylidene-indan-1,3-diones 6a-d) were also studied kinetically and found to be 5-24 times slower than predicted by eqn (1).
authors.affiliation: Department Chemie und Biochemie, Ludwig-Maximilians-Universität, Butenandtstr. 5-13 (Haus F), 81377 München, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Seeliger
authors.forename: Herbert
authors.initials: H
authors.lastname: Mayr