| abstract |
A new process is disclosed, particularly simple, convenient and practical, for the direct synthesis of metallocenes of formula (I): (Cp)(ZR1m)n(A)rMLpL'q wherein (ZR1m)n is a divalent group bridging Cp and A; Cp is a substituted or unsubstituted cyclopentadienyl group; A is -O-, -S-, -N(R2)-, wherein R2 is hydrogen, alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl, or A has the same meaning of Cp; M is a transition metal belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups; L is a monoanionic sigma ligand, such as alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl, optionally containing Si or Ge; L' is halogen or -OR5, R5 being a hydrocarbon radical; m is 1 or 2; n is 0-4; r is 0 or 1; p is 1-3; q is 0-2. Said process comprises reacting the ligand (Y-Cp)(ZR1m)n(A-Y)r, wherein Y is a suitable leaving group, with at least 1 molar equivalent of ML's in the presence of at least (1+r+p) molar equivalents of LjB or LMgL', wherein B is an alkaline or alkaline-earth metal, s ranges from 3 to 6, and j is 1 or 2. |