Structure-Reactivity Relationship Studies for Guanidine-Organocatalyzed Direct Intramolecular Aldolization of Ketoaldehydes.
Fiche publication
Date publication
décembre 2010
Auteurs
Membres identifiés du Cancéropôle Est :
Dr WAGNER Alain
Tous les auteurs :
Ghobril C, Hammar P, Kodepelly S, Spiess B, Wagner A, Himo F, Baati R
Lien Pubmed
Résumé
Structure-reactivity studies are performed to explore the reaction mechanism of the guanidine-catalyzed intramolecular aldol reaction of ketoaldehydes. A large number of guanidine and guanidine-like catalysts are synthesized and their properties studied. Kinetic profiles and pK(a) values of the catalysts are measured and correlated to reaction barriers calculated using density functional theory (DFT). The DFT calculations show that structural rigidity influences the pKa of the guanidines. Although the basicity is a very important factor in the catalysis, it is not sufficient to fully account for its catalytic efficiency. The availability of two aligned nitrogen reaction sites for proton shuttling in the transition state is an essential feature that helps to rationalize the reactivity pattern and the activation mode for this family of organocatalysts.
Référence
Chemcatchem. 2010 Dec;2(12):1573-81.