Angewandte Chemie International Edition
© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Cover Picture (Angew. Chem. Int. Ed. Engl. 12/1991)
The title picture shows in the center a computed ball-and-stick model of methyltrioxorhenium (MTO), photographed hot off the screen! This readily accessible organometal oxide is easy to purify, stable well above its melting point, soluble in organic solvents and water (without decomposition), and stable in acid and in air. Add to these excellent chemical properties exceptional catalytic qualities. MTO supported on A12O3 catalyzes olefin metathesis and ring-opening metathetical polymerization (reactions depicted at the top and bottom of the cover picture, respectively), but also the epoxidation of olefins with H2O2 (right) and the synthesis of olefins from aldehydes and diazoalkanes (left). More on this impressive catalyst is to be found in three communications by W. A. Herrmann et al. on p. 1636ff.