The Activity of a Catalyst from Nickel Chloride and Methyl-hydropolysiloxane in the Hydrogenation of Olefins

Abstract

Abstract The reaction of anhydrous nickel(II) chloride with methylhydropolysiloxane has been found to give an active catalyst for the hydrogenation of olefins. These two reagents react readily at 120–170°C, with the evolution of hydrogen, to form a black-colored substance which has been used as the catalyst. The catalytic activity has been found to depend on the amount of hydrogen evolved during the reaction and on the methylhydropolysiloxane : nickel chloride ratio. The most active catalyst has been obtained by using the reagents in the Si : Ni ratio of 25 : 1 and by intercepting the reaction as soon as the hydrogen evolution amounted to 1.0 mol per mole of nickel chloride. Cyclohexane has been successfully used as a solvent. However, the presence of diethyl ether or tetrahydrofuran has considerably deactivated the catalyst. The catalyst deactivated by ether has, though, been highly activated by adding a large excess of water.