C–C Coupling Reactions of Pentacarbonyl(trifluoroethenyl isocyanide)chromium with Cyclopentadienyl Complexes

The nucleophic attack of the trifluoroethenyl group of pentacarbonyl(trifluoroethenyl isocyanide)chromium 2 by various cyclopentadienyl ligand containing nucleophiles 1a – f allow an efficient synthesis of functionalized cyclopentadienyl complexes 3a – f . Extension of this method to 1,1′‐dilithioferrocene ( 4a ) and 1,1′‐dilithioruthenocene ( 4b ) yields the difunctionalized derivatives 5a and b , respectively. In general compounds of type 3 and 5 are obtained as mixtures of the E and Z isomers. The crystal and molecular structures of Z ‐ 3a , Z ‐ 3b , Z ‐ 3c and E , Z ‐ 5a were elucidated by X‐ray diffraction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)