Highly regio- and chemoselective palladium(0)-mediated allylic substitution of difunctional allylic halides with phenols

An efficient Pd(0)-mediated, base-assisted reaction of phenols with difunctionalised allylic halides results in the formation of coupled products in good yields. The reactions proceed with excellent stereo-, regio- and chemocontrol. An appropriately functionalised Weinreb amide, synthesised by this methodology, undergoes halogen-lithium exchange and subsequent intramolecular 1,2-carbonyl addition/elimination to give an advanced macrocyclic intermediate with potential use in the synthesis of likonide B. (C) 2010 Elsevier Ltd. All rights reserved.