NOVEL REARRANGEMENT REACTIONS .2. THERMAL REARRANGEMENT STEREOSPECIFICITY OF COMPLEX (ME2SISIME2)[(ETA(5)-INDH(4))FE(CO)](2)(MU-CO)(2)

The catalytic hydrogenation of the indenyl complex (Me2SiSiMe2)[(eta(5 )-Ind)Fe(CO)](2)Cu-CO)(2) (2) in CH2Cl2 afforded the tetrahydroindenyl complex (Me2SiSiMe2)[(eta(5)-IndH(4))Fe(CO)](2)(mu-CO)(2) (3), existi ng as a mixture of cis and trans isomers (3c and 3t), which were separ ated by column chromatography. When the two isomers were heated in xyl ene, respectively, the cis substrate 3e rearranged to the trans produc t [Me2Si(eta(5)-IndH(4))Fe(CO)(2)](2) (4t), while the trans substrate 3t yielded the cis product [Me2Si(eta(5)-IndH(4))Fe(CO)(2)](2) (4c). T his indicates that the rearrangement reaction is stereospecific, which is consistent with the result observed in the rearrangement of comple x (Me2SiSiMe2)[(eta(5)-t-BUC5H3)Fe(CO)](2)(mu-CO)(2) (5). By analogy w ith the mechanism proposed based on detailed investigations of 5, the pathway for formation of 4 is described. Molecular structures of 3c, 3 t, 4t, and 4c were determined by X-ray diffraction.