title: Aldehyde umpolung by N-heterocyclic carbenes: NMR characterization of the Breslow intermediate in its keto form, and a spiro-dioxolane as the resting state of the catalytic system.
authors: Cologne University, Department of Chemistry, Greinstrasse 4, 50939 Köln, Germany. berkessel@uni-koeln.de
authors: Albrecht
authors: A
authors: Berkessel
authors: Silvia
authors: S
authors: Elfert
authors: Kerstin
authors: K
authors: Etzenbach-Effers
authors: J Henrique
authors: JH
authors: Teles