Use of the Mn=C=C system in organometallic and organic synthesis

The present review summarizes the syntheses, structures, physicochemical properties and reactivity of complexes containing eta(1)-, mu-, mu(3)- and mu(4)-vinylidene ligands. Consideration of mononuclear vinylidene complexes is limited to cymantrene derivatives, one of which, viz. C-p(CO)(2)Mn-C=CHPh (1), has served as the precursor for syntheses of many organometallic and some organic compounds. The reactions between phosphites P(OR)(3) and complex 1 afford styrylphosphonates PhCH=CHP(O)(OR)(2). All the transformations of complex 1 occur under very mild conditions. Special attention is paid to heterometallic complexes, containing Mn, Fe and the platinum Group metals with bridging vinylidene ligands. The Mn=C=CHR system is used as a "building block" for a series of dimetal mu-vinylidene complexes including Mn-M bonds (M = Mo, W, Mn, Re, Fe, Rh, Pd, Pt, Cu) and trimetallic MnFePt mu(3)-vinylidene clusters. Transmetalation reactions of the Mnpd and MnPt complexes have given a series of mu(4)-vinylidene PdFe3 and PtFe3 clusters. Transfer of vinylidene from the Mn atom to another metal atom (Re), to the dinuclear (FePt) and cluster (Os-3, PdFe3, PtFe3) systems has been shown. A systematic study of a dependence of structural and spectroscopic parameters of mono-, di-, td- and tetra-nuclear complexes on the vinylidene coordination mode has been carried out. (C) 2007 Elsevier B.V. All rights reserved.