MEHRFACHBINDUNGEN ZWISCHEN HAUPTGRUPPENELEMENTEN UND UEBERGANGSMETALLEN XXVIII. CYCLOADDITION VON HETEROKUMULENEN AN OXORHENIUM-HALBSANDWICH-KOMPLEXE: SYNTHESE NEUARTIGER METALLACYCLEN

Article abstract of DOI:10.1016/0022-328X(86)80229-7

The dinuclear oxorhenium complex (η⁵-C5Me5)2Re2O4 reacts with diphenylketene to give, via formal <2+2>-cycloaddition at the (hypothetical) fragment (η⁵-C5Me5)ReO2, the novel, four-membered metallacyclic compound (η⁵-C5Me5)Re(=O)(η²-O2CCR2) (R=C6H5).Cleavage of the dinuclear Re2O2 core with addition of the heterocumulene to a ReO group is also observed when phenyl isocyanate is used instead of diphenyl ketene.In this case, the cyclic derivative (η⁵-C5Me5)Re(=O)(η²-OCONR)(R=C6H5) containing a O,N-coordinated ligand in the four-membered structure has been formed.In contrast, the mononuclear half-sandwich complex (η⁵-C5Me5)ReO3 reacts with diphenylketene according to a formal <3+2>-cycloaddition at a ReO2 core to give the five-membered metallacycle (η⁵-C5Me5)Re(=O)(η²-O2COCR2) (R=C6H5).The three cycloaddition products have been structurally characterized by means of X-ray diffraction techniques.