Direct lithiation of (cyclobutadiene)tricarbonyliron and ((trimethylsilyl)cyclobutadiene)tricarbonyliron with sec-butyllithium: selective para metalation
作者:Uwe Bunz
DOI:10.1021/om00033a035
日期:1993.9
(Cyclobutadiene)tricarbonyliron (1a) is metalated on treatment with sec-BuLi in THF, as could be shown by reaction of the product (lithiocyclobutadiene)tricarbonyliron (1b) with a variety of electrophiles (inter alia trimethylchlorosilane, methyl disulfide, methyl iodide, and diiodoethane); the respective adducts were obtained in good yields. Similarly, metalation of ((trimethylsilyl)cyclobutadiene)tricarbonyliron (1c) affords (3-lithio-l-(trimethylsilyl)cyclob-utadiene)tricarbonyliron (3a), which has also been trapped with standard electrophiles. No products of ortho metalation were observed.
New Convenient Methods for the Preparation of Pendant Chain Cyclobutadiene Tricarbonyliron Complexes
作者:Christopher M. Adams、John E. Schemenaur、Ellen S. Crawford、Scott A. Joslin
DOI:10.1080/00397919208021603
日期:1992.5
synthesis of precursors to pendant chain cyclobutadiene metal complexes. Facile reduction of the mono and disubstituted 1,2-cyclobutenediones gave cyclobutenediols which were converted to their corresponding trans dibromides with PBr3. Reduction and complexation using Fe2(CO)9 formed the pendant chain cyclobutadiene tricarbonylironcomplexes in good yields.