Solvation Accounts for the Counterintuitive Nucleophilicity Ordering of Peroxide Anions

Mayer, Robert J.; Tokuyasu, Takahiro; Mayer, Peter; Gomar, Jerome; Sabelle, Stephane; Mennucci, Benedetta; Mayr, Herbert und Ofial, Armin R. (2017): Solvation Accounts for the Counterintuitive Nucleophilicity Ordering of Peroxide Anions. In: Angewandte Chemie-international Edition, Bd. 56, Nr. 43: S. 13279-13282

Abstract

The nucleophilic reactivities (N, s(N)) of peroxide anions (generated from aromatic and aliphatic peroxy acids or alkyl hydroperoxides) were investigated by following the kinetics of their reactions with a series of benzhydrylium ions (Ar2CH+) in alkaline aqueous solutions at 20 degrees C. The second-order rate constants revealed that deprotonated peroxy acids (RCO3-), although they are the considerably weaker Bronsted bases, react much faster than anions of aliphatic hydroperoxides (ROO-). Substitution of the rate constants of their reactions with benzhydrylium ions into the linear free energy relationship lgk=s(N)(N+E) furnished nucleophilicity parameters (N, s(N)) of peroxide anions, which were successfully applied to predict the rates of Weitz-Scheffer epoxidations. DFT calculations with inclusion of solvent effects by means of the Integral Equation Formalism version of the Polarizable Continuum Model were performed to rationalize the observed reactivities.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Chemie und Pharmazie > Department Chemie
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie
• ISSN: 1433-7851
• Sprache: Englisch