Unexpected ring-expansion of “axially prostereogenic” biaryl lactones by methylenephosphoranyl-substituted imido complexes of molybdenum and tungsten
摘要:
Transition-metal-substituted phosphorus ylides M(NtBu)2(CH=PPh3)Cl, with M=Mo, W, have been shown to be useful C-nucleophiles for the selective C-0 bond cleavage of benzocoumarin-type ''axially prostereogenic'' biaryl lactones. The reaction of the metallo-ylide with the lactone leads to an eight-membered metallacycle as established by spectroscopic data and confirmed by an X-ray diffraction study of one of the products.
(α-Triphenylphosphonio)methylidene imido complexes of molybdenum, tungsten and rhenium: the first complexes exhibiting metal–ligand multiple-bonding with two carbon as well as two nitrogen centres
摘要:
报告了具有四个Ï-供体配体的四面体配合物[Mo(NBut)2(CHPPh3)2]、[W(NBut)2(CHPPh3)2]和[Re(NBut)3(CHPPh3)]的合成;W(NBut)2(CHPPh3)2]的 X 射线结构显示,亚氨基配体[NBut]和(δ-三苯基膦)亚甲基官能团[CHPPh3+]都与 d0 金属中心发生了强烈的Ï-相互作用。