AN UNUSUAL CYCLOPENTAANNULATION REACTION - THERMOLYSIS OF AN ALPHA,BETA-UNSATURATED FISCHER CARBENE COMPLEX ANCHORED ON A FE-2(CO)(6)(MU-SE)(2) CORE

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