REACTIONS OF CATIONIC VINYLIDENE COMPLEXES [FE(=C=C(R1)R2)(ETA-C5H5)(DPPM)]+ [DPPM = BIS(DIPHENYLPHOSPHINO)METHANE] WITH NUCLEOPHILES - STEREOSELECTIVE SYNTHESIS AND CRYSTAL-STRUCTURE OF THE ALKENYL COMPLEX (E)-[FE(C(H)=C(ME)PH)(ETA-C5H5)(DPPM)]

The reactivity of the cationic vinylidene complexes [Fe{= C = C(R1)R2}(eta-C5H5)(dppm)]+ toward different nucleophiles has been investigated. Whereas the disubstituted complexes (R1 = Me; R2 = Ph or (t)Bu) are unreactive with water and methanol, the addition of the anion hydride proceeds stereoselectively to give the alkenyl E isomers. The structure of (E)-[Fe{C(H) = C(Me)Ph}(eta-C5H5)(dppm)] has been determined by an X-ray diffraction study. Nucleophilic additions to the unsubstituted complex (R1 = R2 = H) have also been examined.