Back Cover: In Silico Design of Heteroaromatic Half-Sandwich RhICatalysts for Acetylene [2+2+2] Cyclotrimerization: Evidence of a Reverse Indenyl Effect (Chem. Eur. J. 40/2013)

Abstract

A reverse indenyl effect occurs in the acetylene [2+2+2] cyclotrimerization to benzene by RhI half-metallocene catalysts with heteroaromatic ligands. In their Full Paper on page 13337 ff., L. Orian, F. M. Bickelhaupt et al. have designed, in silico, heteroaromatic ligands that are isoelectronic to the classic hydrocarbon cyclopentadienyl and indenyl anions. Mechanistic explorations and activation strain analyses reveal and explain the reverse indenyl effect, that is, a decrease in reactivity associated with an increased metal slippage. On the cover, the initial bis- acetylene complexes of all ligands are shown: the different extent of Rh slippage controls the orientation of the alkynes, which resembles the pose of the wings of Siproeta stelenes, the Central American butterfly shown.