Addition of a diphosphirenium salt to palladium(0) complexes: The first examples of diphosphametallacyclobutenes

Article abstract of DOI:10.1021/om00008a003

P-Bis(diisopropylamino)-C-(diisopropylamino)diphosphirenium tetrafluoroborate (1) reacts with palladium tetrakis(triphenylphosphine), affording the tetrafluoroborate salt of 2,2-bis(triphenylphosphine)-1,3-diphospha-2-pallada(II)cyclobutene 2 in 70% yield. Exchange of the triphenylphosphine ligands occurs with diphenylmethylphosphine, dimethylphenylphosphine, trimethylphosphine, and 1,2-bis(diphenylphosphino)ethane, leading to the corresponding complexes 3-6 in good yields.