Bis(triphenylphosphine)palladium Cycloheptadienynylium Tetrafluoroborate:  A Palladium Complex of Tropyne

Palladium complexes of cyclohepta-3,5-dien-1-yne (<b>4</b>) and cyclohepta-1,5-dien-3-yne (<b>5</b>) have been prepared and converted to a palladium complex of tropyne (<b>6</b>) by treatment with triphenylcarbenium tetrafluoroborate.