Selective hydrogenations of dienes and oiefins by [W2(OCH2But)6(py)2]

Hydrocarbon solutions of [W2(OCH2But)6(py)2] in the presence of H2(3 atm, 23 °C) hydrogenate linear 1,3-dienes to 3-enes, 1,3- and 1,5-cyclooctadiene to cyclooctene, 1,3-cyclohexadiene to cyclohexene, cyclopentene to cyclopentane, and norbornene to norbornane, but do not hydrogenate α- and internal olefins to alkanes, or internal conjugated or unconjugated dienes.