Sulphur-containing metal complexes. Part 4. Preparation of fac-tri-substituted carbonyl complexes of chromium(0) and tungsten(0) containing a phosphine, phosphite, or isocyanide ligand in addition to a chelate ring with carbene carbon and sulphur donor atoms

Abstract

The reaction of LiBu with pentacarbonyl(thioether) complexes of chromium and tungsten [M(CO)₅S(CH₂R²)R¹], in the presence of or prior to the addition of a π-acid ligand L, followed by alkylation, produces a series of tri-substituted carbonyl complexes of the type fac-[[graphic omitted]R¹)R²}]. A proposed mechanism involving a double consecutive carbonylation is substantiated by the formation of a cis-tetracarbonyl(amino-carbenethio)-chelate as a by-product during one of the reactions in which L = CNBu^t.