Preparation of ditungsten hexakis(2,6-dimethylphenoxide) and its reaction with acetylenes to give tungstenacyclobutadiene complexes

Article abstract of DOI:10.1021/om00138a039

The reaction between W₂(O-t-Bu)₆ and excess, fused 2,6-dimethylphenol produces W₂(DMP)₆ in high yield (DMP = 2,6-dimethylphenoxide). W₂(DMP)₆ reacts smoothly with 3 equiv of 2-butyne or 3-hexyne to give tungstenacyclobutadiene complexes of the type W(C₃R₃)(DMP)₃ virtually quantitatively. The W(C₃R₃)(DMP)₃ complexes react smoothly with 3 equiv of HCl in pentane to give the parent trichloride complexes W(C₃R₃)Cl₃ virtually quantitatively. A simple large-scale preparation of W₂(DMP)₆ consists of the addition of DMPH to WCl₆ to give W(DMP)₃Cl₃ followed by reduction of W(DMP)₃Cl₃ in diethyl ether.