title: OH-Pd(0) interaction as a stabilizing factor in palladium-catalyzed allylic alkylations.
abstract: In palladium-catalyzed alkylations of allylic acetates with malonate as nucleophile, catalysts with oxazoline ligands bearing hydroxymethyl substituents in 4-position have been shown by density functional theory computations to undergo a conformational change on nucleophilic attack, which is accompanied by reduction of Pd(II) to Pd(0). The conformations of the Pd(0) complexes were shown to be governed by the presence of a hydrogen bond with the metal center acting as a hydrogen bond acceptor. The conformational change, which is absent in catalysts with O-alkylated analogs, largely affects the enantioselectivity of the catalytic process. This process is a previously uninvestigated example of where this type of weak hydrogen bond has been shown to influence the stereochemistry of a chemical reaction.
authors.affiliation: Department of Chemistry, Organic Chemistry, Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
authors.forename: Kristina
authors.initials: K
authors.lastname: Hallman
authors.forename: Anders
authors.initials: A
authors.lastname: Frölander
authors.forename: Tebikie
authors.initials: T
authors.lastname: Wondimagegn
authors.forename: Mats
authors.initials: M
authors.lastname: Svensson
authors.forename: Christina
authors.initials: C
authors.lastname: Moberg