Control of reactive site in Palladium-Catalyzed grignard Cross-Coupling of arenes containing both bromide and triflate

Article abstract of DOI:10.1016/S0040-4039(97)01655-9

Reaction of 4-bromophenyl triflate (1) with phenylmagnesium bromide in the presence of 5 mol % of PdCl₂(dppp) gave 97% yield of 4-bromobiphenyl (2a), which was formed by selective replacement of triflate in 1 by phenyl. On the other hand, bromide in 1 was substituted with the phenyl Grignard reagent selectively by use of PdCl₂(meo-mop)₂ to give 4-biphenyl triflate (3a) in high yield. The selective substitution was demonstrated to take place at the oxidative addition step to a palladium(0) species in a stoichiometric reaction of 1 with palladium(0) phosphine complexes.