Synthesis of (E)- and (Z)-bromobis(triphenylphosphine)palladium and the X-ray Crystal Structure Determination for the E-Isomer

Article abstract of DOI:10.1021/jo00098a043

We report the preparation of (E)- and (Z)-<2-((dimethoxyphosphinyl)oxy)-3-ethoxy-3-oxo-1-propenyl>bromobis(triphenylphosphine)palladium from the corresponding ethyl (E)- and (Z)-3-bromo-2-<(dimethoxyphosphinyl)oxy>propenoate and the X-ray crystal structure determination for (E)-<2-((dimethoxyphosphinyl)oxy)-3-ethoxy-3-oxo-1-propenyl>bromobis(triphenylphosphine)palladium.The (E)-palladium complex was reduced to (E)-3-<2H>phosphoenolpyruvate by treatment with a mixture of trifluoroacetic acid-d/trifluoroacetic anhydride under strict anhydrous conditions.The 1H-NMR spectrum of the E-isomer obtained from the reduction of the palladium complex was identical to the 1H-NMR spectra of (E)-3-<2H>phosphoenolpyruvate previously prepared by two different synthetic strategies.The X-ray structure of the palladium phosphoenolpyruvate analogue is the first X-ray structure of any 3-substituted phosphoenolpyruvate analogue reported and along with its synthesis and transformation interrelates the stereochemistry of several 3-substituted phosphoenolpyruvate analogues.