An unusual cyclopentaannulation reaction: thermolysis of an α,β-unsaturated fischer carbene complex anchored on a Fe<SUB>2</SUB>(CO)<SUB>6</SUB>(μ-Se)<SUB>2</SUB> core

An unusual annulation of a Fischer carbene complex anchored on a Fe2(CO)6(μ-Se)2 core is examined. Thermolysis of Fe2(CO)6{μ-SeC(Ph)=C(Se)[(OEt)C=Cr(CO)5]} in THF yields an unusual annulated product, [Fe2(CO)6Se2{μ-(CO)3Cr(η5-C5H(CH2Ph)(Ph)(OEt))}], as characterized by IR and 1H, 13C, and 77Se NMR spectroscopies, and its structure has been established by single-crystal X-ray diffraction