SILICA-BASED ZINC CATALYSTS. THEIR PREPARATION AND USE IN THE ALKOXYCARBONYLATION OF AMINES

摘要

The present invention relates to silica-based heterogeneous zinc compounds which are suitable as catalysts in the reaction of amines with dialkyl carbonates to produce carbamates. The catalysts have the formula [SiO2]—CH2—CHR—X—COOZn[Y], wherein [SiO2] represents a silica carrier selected from the group consisting of ordered mesoporous silica and irregular amorphous narrow pore silica, R represents a moiety selected from the group consisting of hydrogen, —CH3, and —CH2CH3, preferably hydrogen, X is an aliphatic chain of 2 to 11 carbon atoms that optionally comprises ether moieties and [Y] represents a mono anion. The invention is also directed towards a method for the preparation of the aforementioned compounds and towards method for the alkoxycarbonylation of amines.