Synthesis and structures of η~1-allenyl and/or -propargyl Pd(II) complexes and their reactivity toward trimethylsilyl pseudohalides, organic thiols, and N-heterocyclic carbene ligands

摘要

Facile oxidative additions of various propargyl halides to [Pd(CH _2CHPh)(PR_3)_2], which could be generated in situ from trans-[PdEt_2(PR_3)_2] (PR _3PMe_3, PEt_3, PMe_2Ph) and styrene, gave the bis(phosphine) η~1-allenyl and/or η~1- propargyl Pd(II) complexes. The chloro ligand in the η~1-allenyl Pd(II) complex could be replaced by pseudohalides to produce the new corresponding pseudohalo complexes, trans-[XPd(CHCCH2)(PMe _3)_2], when treated with trimethylsilyl pseudohalides (Me_3SiX: X = NCS, CN, N_3). The η~1-allenyl complex was also converted into the thiolato complexes when treated with various organic thiols. In addition, the phosphine ligand in the η~1- allenyl complex could be replaced by NHC (N-heterocyclic carbene) to produce η~1-allenyl or -propargyl Pd(II) complex possessing the NHC ligand, depending on the coordinated η~1-allenyl moiety. On the other hand, oxidative addition of phenyl propargyl sulfide to the [Pd(CH _2CHPh)(PMe_3)_2] gave a phenyl thiolato η~1-allenyl Pd(II) complex, trans-[(C_6H _5S)Pd(CHCCH_2)(PMe_3)_2].