title: Chiral pyrroline-based Ugi-three-component reactions are under kinetic control.
abstract: Although it is often assumed that the stereochemistry in Ugi multicomponent reactions is determined in the final Mumm rearrangement step, experimental and computational evidence that Ugi reactions on hydroxylated pyrrolines proceed under kinetic control is reported. The stereochemistry of the reaction is established with the addition of the isocyanide to the intermediate iminium ion, whose conformation is determined by its substitution pattern.
authors.affiliation: Leiden Institute of Chemistry, Leiden University , P.O. Box 9502, 2300 RA Leiden, The Netherlands.
authors.forename: Erwin R
authors.initials: ER
authors.lastname: van Rijssel
authors.forename: Theodorus P M
authors.initials: TP
authors.lastname: Goumans
authors.forename: Gerrit
authors.initials: G
authors.lastname: Lodder
authors.forename: Herman S
authors.initials: HS
authors.lastname: Overkleeft
authors.forename: Gijsbert A
authors.initials: GA
authors.lastname: van der Marel
authors.forename: Jeroen D C
authors.initials: JD
authors.lastname: Codée