Use of a bulky phosphine of weak sigma-donicity with palladium as a versatile and highly-active catalytic system: allylation and arylation coupling reactions at 10(-1)-10(-4) mol% catalyst loadings of ferrocenyl bis(difurylphosphine)/Pd

摘要

Carbon-carbon(sp(2)sp(2) and sp(1)-sp(2)) and carbon-nitrogen (nucleophilic allylation) coupling processes are promoted by a catalytic system containing [PdCl(eta(3)-C3H5)](2) with the new ferrocenyl bis(difurylphosphine) 1,1'-bis[di(5-methyl-2-furyl)phosphino] ferrocene, Fc[P(Fu(Me))(2)](2). Starting from aryl bromides or allylic acetates this versatile catalyst system may be used at low palladium loadings (10(-1)-10(-4) mol%) in some Heck, Suzuki, Sonogashira and allylic amination reactions to give cross-coupled products in excellent yield. Remarkably high activity is obtained in allylic substitution reactions, providing a significant impetus for the development of bulky phosphines possessing weak sigma-donicity for this particular reaction. (c) 2005 Elsevier Ltd. All rights reserved.