A key role for iodobenzene in the direct C-H bond functionalisation of benzoxazoles using PhI(OAc)2 mediated by a Pd(OAc)2/1,10-phenanthroline catalyst system: in situ formation of well-defined Pd nanoparticles

PhI(OAc)(2) has previously been reported as a reagent for the direct arylation of C-H bonds in benzoxazole in a pd(II/IV)-mediated process. However, evidence reported here suggests this reagent degrades to iodobenzene under the literature reported reaction conditions. Further, we present evidence for the rapid formation of Pd-0 nanoparticles in this reaction, leading us to question what is the active catalytic Pd phase in coupling chemistry? (C) 2013 Elsevier Ltd. All rights reserved.