A Series of (Butadiene)rhodium(I) Complexes with an Open-Sandwich- or Half-Sandwich-Type Structure

Attempts to elucidate the mechanism of the rhodium-catalyzed cyclooligomerisation of butadienes lead to the synthesis of the mono(diene)- and bis(diene)rhodium(I) complexes such as 1 and 2. The rather labile Rh−OS(O)2CF3 bond seems to determine the reactivity of the open-sandwich- or half-sandwich-type compounds.