Pentafluorophenyl imidato palladium(II) complexes:: catalysts for Suzuki cross-coupling reactions

Novel N-bonded imidato complexes of general formula [Pd(N-N)(C6F5)(imidate)] (imidate = maleimidate, succinimidate or phthalimidate; N-N = 2,2'-bipyridine (bipy), 4,4'-dimethyl-2,2'-bipyridine (Me(2)bipy) or N,N,N',N'-tetramethylethylenediamine (tmeda)), [NBu4][Pd(C6F5)(H2O)(succinimidate)(2)] and [NBu4]-[Pd (C6F5)(L)(succinimidate)(2)] (L = PPh3 or t-BuNC) have been synthesised. These complexes are air-, light- and moisture-stable. The crystal structures of [Pd(tmeda)(C6F5)(maleimidate)]center dot H2O-0.5CHCl(3), [NBu4][Pd(C6F5)-(H2O)(succinimidate),]-H2O and [NBu4][Pd(C6F5)(t-BuNC)(succinimidate)(2)]center dot 2H(2)O have been determined by X-ray diffraction. Many of these new complexes are shown to be active phosphine-free palladium catalysts/precatalysts for the Suzuki cross-coupling reactions of aryl bromides and aryl chlorides with phenylboronic acid.