Back Cover: (Adv. Synth. Catal. 13/2013)

The cover picture, provided by Sandrine Ventre, Etienne Derat, Muriel Amatore, Corinne Aubert and Marc Petit, illustrates the rapid and selective head‐to‐head ( E )‐dimerisation of arylacetylenes catalyzed by a simple hydrido‐cobalt complex under mild conditions at room temperature. The process is based on a cobalt‐promoted activation of a CH acetylenic bond affording a new dihydrido complex. DFT computational studies support then an hydrocobaltation pathway ( TS ‐ BC ) over carbocobaltation ( TS ‐ BE ) starting from this intermediate. Subsequent reductive elimination completes the catalytic cycle and releases the desired ( E )‐enyne with excellent yield and selectivities. This methodology is illustrated in the Full Paper by Ventre et al. on pages 2584–2590 (DOI: 10.1002/adsc.201300486) .