Hydrogen-bond-assisted activation of allylic alcohols for palladium-catalyzed coupling reactions

Abstract

We report direct activation of allylic alcohols using a hydrogen-bond-assisted palladium catalyst and use this for alkylation and amination reactions. The novel catalyst comprises a palladium complex based on a functionalized monodentate phosphoramidite ligand in combination with urea additives and affords linear alkylated and aminated allylic products selectively. Detailed kinetic analysis show that oxidative addition of the allyl alcohol is the rate-determining step, which is facilitated by hydrogen bonds between the alcohol, the ligand functional group, and the additional urea additive. Hydrogen Bond Rule(s): Direct activation of allylic alcohols and subsequent alkylation and amination reactions are reported. The new catalyst is based on functionalized palladium and phosphoramidite ligands to allow hydrogen bond-assisted activation. Kinetic data are in line with this mechanism as the oxidative addition is the rate-determining step. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.