Stepwise oxidation of a μ-alkylidene palladium–tungsten compound

Structure and Reactivity of Early−Late Heterobimetallic Complexes

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38 Crystal structure of [Cp(O)W(μ-CTolC 6 H 4 CH 2 NMe 2 )(μ-CO)PdCl]. Reprinted from ref . Copyright 1997 Royal Society of Chemistry.

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“…Oxidation of these complexes with trimethylamine N -oxide has afforded the complexes [Cp(O)W(μ-CTolC 6 H 4 CH 2 NMe 2 )(μ-CO)PdCl] (see Figure ) and [Cp(O)W(μ-O)(μ-CTolC 6 H 4 CH 2 NMe 2 )PdCl] in low yields. The X-ray crystal structures of both these complexes, which retain the starting μ-alkylidene framework, have been solved …”

“…Reaction of an excess of trimethylamine N -oxide (>5 equiv) with the μ-alkylidene tungsten−palladium complex [(OC)CpW(μ-CO)(μ-CArC 6 H 4 CH 2 NMe 2 )PdCl] is nonselective, and although the ketone product of the oxidation of the alkylidene bridge was isolated in 77% yield, the organometallic products have not been identified. Using a 2−4-fold excess of Me 3 NO allows the isolation in low yield of tungsten-oxidized species in which either the terminal carbonyl or both the carbonyls are replaced by oxo ligands …”

“…The X-ray crystal structures of both these complexes, which retain the starting µ-alkylidene framework, have been solved. 201 Finally, Chetcuti et al have prepared and crystallographically characterized a methylene-bridged tungsten-nickel compound, [(OC) 2 CpW(µ-CH 2 )(µ-CO)-NiCp*], by the reaction of diazomethane with [CpW(µ-CO) 3 NiCp*]. 202…”

“…Using a 2-4-fold excess of Me 3 NO allows the isolation in low yield of tungsten-oxidized species in which either the terminal carbonyl or both the carbonyls are replaced by oxo ligands. 201…”