title: Nucleophilicity Parameters of Arylsulfonyl-Substituted Halomethyl Anions.
abstract: The rates of the reactions of the arylsulfonyl-substituted carbanions carrying α-chloro and α-bromo substituents (1a-e) with quinone methides 2a-g and benzylidenemalonates 2h and 2i in DMSO were determined photometrically at 20 °C. The reactions were performed under pseudo-first-order conditions, and the second-order rate constants were obtained as the slopes of the plots of the pseudo-first-order rate constants versus the concentrations of the reactants used in excess. The second-order rate constants correlate linearly with the parameters E of the reference electrophiles according to the linear free energy relationship log k2(20 °C) = sN(N + E), which allowed us to derive the nucleophile-specific parameters N and sNof carbanions 1a-e. The resulting nucleophilicity parameters N (23 < N < 29) reveal the title compounds to be among the most reactive nucleophiles so far integrated on our comprehensive nucleophilicity scale.
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München , Butenandtstrasse 5-13, Haus F, 81377 München, Germany.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München , Butenandtstrasse 5-13, Haus F, 81377 München, Germany.
authors.forename: Quan
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München , Butenandtstrasse 5-13, Haus F, 81377 München, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Mayer
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München , Butenandtstrasse 5-13, Haus F, 81377 München, Germany.
authors.forename: Herbert
authors.identifier: 0000-0003-0768-5199
authors.initials: H
authors.lastname: Mayr