title: Palladium-catalyzed coupling of allyl acetates with aldehyde and imine electrophiles in the presence of Bis(pinacolato)diboron.
abstract: [reaction: see text] An efficient one-pot procedure was developed for palladium-catalyzed electrophilic substitution of allyl acetates (2a-h) in the presence of bis(pinacolato)diboron (1). These reactions proceed with an excellent regioselectivity and with a remarkably high stereoselectivity. The catalytic transformations take place via palladium-catalyzed formation of allyl boronates, which subsequently react with aldehyde (3) and sulfon-imine (4) electrophiles to afford homoallylic alcohols (5a-h) and amines (6a-d), respectively. A particularly interesting mechanistic feature is that the allylic substitution of the transient allyl boronate with sulfon-imine requires palladium catalysis. This finding indicates that the formation of the homoallylic amine derivatives (6a-d) involves bis-allylpalladium intermediates.
authors.affiliation: Stockholm University, Arrhenius Laboratory, Department of Organic Chemistry, SE-106 91, Stockholm, Sweden.
authors.forename: Sara
authors.initials: S
authors.lastname: Sebelius
authors.forename: Olov A
authors.initials: OA
authors.lastname: Wallner
authors.forename: Kálmán J
authors.initials: KJ
authors.lastname: Szabó