Methyltrioxorhenium as Catalyst for Olefin Metathesis

No cocatalysts are needed as additives when methyltrioxorhenium (MTO) supported on acidic carriers is employed to catalyze the metathesis of functionalized olefins. A typical system is MTO/Al 2 O 3 −SiO 2 , which is active, for instance, in the metathesis of ally1 halides, allylsilanes, unsaturated carboxylates, and nitriles. MTO in combination with R n AlCl 3‐ n is a homogeneous catalyst in ring‐opening polymerizations (RCH 3 , C 2 H 5 ; n = 1,2).