Patent ID: 6995267

Claim:
A process for preparing substituted cyclopentadiene compounds, which comprises the following steps: (A) reacting a compound of the formula I where the substituents have the following meanings: M 1 is Co, Rh or Ir, X is fluorine, chlorine, bromine, iodine, trifluorosulfonyl, tosyl, Y are identical or different and each have the formula II where the variables have the following meanings: E 1 –E 5 are each carbon or at most one E 1 to E 5 is phosphorus, R 1 –R 5 are each, independently of one another, hydrogen, C 2 –C 20 -alkyl, C 2 –C 20 -alkenyl, C 6 –C 20 -aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl part and 6–20 carbon atoms in the aryl part, trialkylsilyl having three independent C 1 –C 20 -alkyl groups, where the organic radicals R 1 –R 5 may also be substituted by halogens and/or nitrogen-, phosphorus-, sulfur- or oxygen-containing groups and two geminal or vicinal radicals R 1 –R 5 may also be joined to form a five- or six-membered ring, with a compound M 2 X n R 6 n-z , where the variables have the following meanings: R 6 is C 1 –C 20 -alkyl, C 2 –C 20 -alkenyl, C 6 –C 20 -aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl part and 6–20 carbon atoms in the aryl part, trialkylsilyl having three independent C 1 –C 20 -alkyl groups or an unsubstituted, substituted or fused, partially unsaturated heterocyclic or heteroaromatic ring system, where the organic radical R 6 may also be substituted by halogens and/or sulfur-, phosphorus, nitrogen- or oxygen-containing groups, M 2 is Li, Na, K, Mg, Al, B, n is 0, 1 or 2 and is less than z, z is an integer corresponding to the oxidation state of M 2 , and (B) reacting the intermediate obtained in this way with iron(III) chloride.