Angewandte Chemie International Edition
Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Cover Picture: Molybdenum and Tungsten Imido Alkylidene Complexes as Efficient Olefin-Metathesis Catalysts (Angew. Chem. Int. Ed. 38/2003)
Molybdenum imido alkylidenes along with the corresponding tungsten complexes have played a critical role in the emergence of catalytic olefin metathesis as one of the key transformations in chemical synthesis. R. R. Schrock and A. H. Hoveyda recount on page 4592 ff the journey that began with the discovery of tantalum alkylidenes and eventually led to the development of highly effective chiral catalysts, and even supported chiral catalysts (shown in the vials), for asymmetric metathesis.