Studies of Hydrogenations and Isomerizations of Olefins and Alkylations of Amines Using Iridium Catalysts

Abstract: This thesis describes three types of reactions that were carried out using iridium catalysts.The first type is the iridium-catalyzed asymmetric hydrogenation of olefins. In paper I, the preparation of a new type of bicyclic thiazole-phosphine based iridium complex was described. The new catalysts have displayed high activity and enantioselectivity in the asymmetric hydrogenation of unfunctionalized olefins. Papers II and III focus on the expansion of the substrate scope for the iridium catalyzed asymmetric hydrogenation in which a number of heterocyclic olefins were evaluated. In paper IV, the enantioselective asymmetric hydrogenation of ?, ?-unsaturated esters was described. The chiral products bearing tertiary stereogenic centers obtained by hydrogenation have great synthetic value and have been used in the synthesis of pharmaceuticals as well as in the total synthesis of natural products.The second type is the asymmetric isomerization of allylic alcohols. In paper V, both cis and trans primary allylic alcohols were isomerized to the corresponding ?-chiral aldehydes in high enantioselectivities by an N,P-chelating iridium complex.The third type is the selective mono-N-alkylation of amines with alcohols. In paper VI, a phosphine/NHC based iridium catalyst was synthesized and applied in the alkylation of amines. It is the first time that this type of transformation is carried out at room temperature.