Binding and activation of aromatic molecules by a molybdenum pi-base

Compounds having the form TpMo(NO)(1-methylimidazole)(eta(2)-L(pi)) (Tp = hydridotris(pyrazolyl)borate; L(pi) = cyclohexene, naphthalene, furan, thiophene, and acetone) were synthesized in 31-41% yield by the reduction of TpMo(NO)Br(2) in the presence of 1-methylimidazole and the respective pi-acidic organic ligand. The structure of the naphthalene complex was confirmed by single-crystal X-ray diffraction. Degradation studies showed the bound aromatics to have half-lives of 37-236 h in acetone solution at 20 degrees C. A tandem addition across the bound ring of the naphthalene complex yielded a free 1,2-dihydronaphthalene in 80% yield following decomplexation.