title: Nucleophilic reactivities of the anions of nucleobases and their subunits.
abstract: The kinetics of the reactions of different heterocyclic anions derived from imidazoles, purines, pyrimidines, and related compounds with benzhydrylium ions and structurally related quinone methides have been studied in DMSO and water. The second-order rate constants (log k(2)) correlated linearly with the electrophilicity parameters E of the electrophiles according to the correlation log k(2) = s(N)(N+E) (H. Mayr, M. Patz, Angew. Chem. 1994, 106, 990-1010; Angew. Chem. Int. Ed. Engl. 1994, 33, 938-957) allowing us to determine the nucleophilicity parameters N and s(N) for these anions. In DMSO, the reactivities of these heterocyclic anions vary by more than six orders of magnitude and are comparable to carbanions, amide and imide anions, or amines. The azole anions are generally four to five orders of magnitude more reactive than their conjugate acids.
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13 (Haus F), 81377 München, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Breugst
authors.forename: Francisco
authors.initials: F
authors.lastname: Corral Bautista
authors.forename: Herbert
authors.initials: H
authors.lastname: Mayr
mesh_terms: D000838:Anions; D004121:Dimethyl Sulfoxide; D007093:Imidazoles / Q000737:chemistry*; D045563:Indolequinones / Q000737:chemistry*; D007700:Kinetics; D015394:Molecular Structure; D011687:Purines / Q000737:chemistry*; D011743:Pyrimidines / Q000737:chemistry*; D013816:Thermodynamics; D014867:Water
chemical_list: D000838:Anions; D007093:Imidazoles; D045563:Indolequinones; D011687:Purines; D011743:Pyrimidines; D014867:Water; C068040:quinone methide; D004121:Dimethyl Sulfoxide