Abstract: Nanoparticles that can be used as hydrosilylation and dehydrogenative silylation catalysts. The nanoparticles have at least one transition metal with an oxidation state of 0, chosen from the metals of columns 8, 9 and 10 of the periodic table, and at least one carbonyl ligand, preferably a silicide.

Abstract: The invention relates to a method for metathesis of one or several reagents comprising a linear or branched hydrocarbon chain containing a double olefinic bond Csp2?Csp2 consisting in reacting said reagent or reagents with a supported metal compound comprising an aluminum oxide-based support to which a tungsten hydride is grafted. Typically, each said reagent or reagents comprises from 2 to 30 carbon atoms. The reagent can be embodied in the form of olefin. The inventive method can be used, for example for producing propylene from ethylene and butane.