Synthesis and Reactivity of a Nucleophilic Palladium(II) Carbene

Two formal palladium carbene complexes, [PC­(sp2)­P]­Pd­(PR3) (3: R = Me; 4: R = Ph) were isolated and characterized from [PC­(sp3)­H2P] ([PC­(sp3)­H2P] = bis­[2-(di-isopropylphosphino)­phenyl]­methane, iPr2P-C6H4-CH2-C6H4-PiPr2). Structural studies and DFT calculations indicate that the interaction between palladium and carbon is best described as a single bond, associated with nucleophilic character at that carbon atom. The characteristics of 3 were probed by reactions with electrophiles (MeI), acids (MeOH and HCl), and para-toluidine.