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Ruthenium cumulenylidene complexes

C. Ruthenium Cumulenylidene Complexes Bearing Bis(pyrazol-1-yl)acetato Ligands... [Pg.134]

Another example for the Tp versus bdmpza analogy is the synthesis of various bdmpza ruthenium cumulenylidene complexes. The... [Pg.134]

Also, bi- and trimetallic cumulene complexes, such as M=C=M, M=M=C, M=M=M and M=C=C=M are known. Cationic ruthenium allenylidene complexes are used as catalysts for ring closing metathesis reactions. Nonlinear optical properties have been measured for the Group 6 cumulenylidene complexes. Also, cationic chromium or iron vinylidene complexes undergo [2-1-2] cycloaddition reactions across imines to give fi-lactams. This reaction is useful for the synthesis of j8-lactam antibiotics. ... [Pg.377]

These observations indicate that when the metal complex is electron-rich, the allenylidene-metal complexes are stable (VI and VII), even on heating or protonation [42]. However, with less electron-rich systems (e.g., PPh3 ligands instead of PCy3 or NHC) the corresponding allenylidene complex was never observed, to the profit of the indenylidene complex VIII. These results suggested that the allenylidene-ruthenium complex is a transient species that rearranges into the indenylidene complex VIII, as was observed for a C5 cumulenylidene [48]. [Pg.258]

Another common class of metal-carbene complexes is that of the vinylidene complexes (whose structure compares to that of allenes), isomers of metal-alkyne complexes. A well-known example is the vinylidene complex [Ru(PPh3)2Cl2( =C=CHPh)], the first unimolecular ruthenium catalyst of olefin metathesis discovered by Grubbs in 1992. - This class is extended to the allenylidenes and cumulenylidenes. ... [Pg.201]


See other pages where Ruthenium cumulenylidene complexes is mentioned: [Pg.101]    [Pg.101]    [Pg.247]    [Pg.152]    [Pg.549]    [Pg.565]    [Pg.632]   


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Cumulenylidene complexes

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