Heterogeneous well-defined catalysts for metathesis of inert and not so inert bonds

Abstract

The present short review article reports four examples of catalytic reactions realised on relatively well-defined supported catalysts. These catalysts were conceptually designed and prepared by a Surface Organometallic Chemistry (SOMC) approach. They were designed for achieving the olefin metathesis reaction, the Ziegler–Natta depolymerisation, the low temperature hydrogenolysis of alkanes and the alkane metathesis reaction. These reactions are “related” to the metathesis of inert bonds. The first example is the silica-supported rhenium (VII) carbene species [(SiO)Re(C-t-Bu)(CH-t-Bu)(CH2-t-Bu)] obtained by grafting Re(C-t-Bu)(CH-t-Bu)(CH2-t-Bu)2 on silica. This catalyst has turned out to be very active in the propene metathesis reaction (initial T.O.F.=0.25 mol/mol Re/s) after an initiation step involving a cross-metathesis reaction between the neopentylidene ligand and propene.