Preparation of Hexacarbonyldicobalt-Complexed 1,3-Dioxa-2-silacycloheptynes

The reaction between 2-butyne-1,4-diol-hexacarbonyldicobalt and a series of dichlorodialkylsilanes (R = Me, Et, CHCH2, and Ph) in the presence of triethylamine results in the formation of the corresponding cobalt-complexed 1,3-dioxa-2-silacycloheptynes, 3−7, as the major products. Complexed silacyclononynes, 8 and 9, and a spirocyclic analogue 10, have also been prepared and characterized. The solid-state structures of 3 and 10 have been determined by X-ray diffraction studies.