Reactions of bis(silyl)palladium(II) complexes with allyl halides. Synthesis of mono(silyl)palladium(II) halides and X-ray structure of trans-PdCl(SiF_2Ph)(PMe_2Ph)_2

摘要

Reactions of trans-Pd(SiF_2Ph)_2L_2 (L=PMe_3 (1a), PMe_2Ph (1b), PMePh_2 (1c)) with allyl bromide readily proceeded in CH_2Cl_2 at -20 deg C to form CH_2=CHCH_2SiF_2Ph and the corresponding bromo(silyl)palladium complexes, trans-PdBr(SiF_2Ph)L_2 (2a-2c) in high selectivities. Treatment of 1a-1c with dry HCl in CH_2Cl_2 at -20 deg C gave silyl chloride complexes, trans-PdCl(SiF_2Ph)L_2 (3a-3c), respectively. Complexes 2a-2c and 3a-3c were isolated and characterized by NMR spectroscopy and/or elemental analysis. One of the complexes, trans-PdCl(SiF_2Ph)(PMe_2Ph)_2 (3b), was identified also by X-ray diffraction study. Relevance of bis-silyl complexes to catalytic silylation of allylic compounds with disilanes is discussed.