Synthesis And Catalytic Performance Of Chiral Ferrocenyldiphosphine Ligand

Due to their fascinating structure, chiral ferrocenyldiphosphine ligands play an important role in asymmetric catalysis. As a ferrocene derivative, Ugi's amine is a key intermediate during the synthesis of chiral ferrocene ligands. The Ugi's amine method allows, once the substituent at C2 has been introduced, a further stereospecific SN1-type reaction of the dimethylamino moiety with different species, which occurs with retention of configuration. So Ugi's amine is widely used in synthesis of chiral ferrocene ligand.Phosphine ligands have been the focus of research for chemists and key factors in chiral drugs or other fine chemicals synthesis because of fine catalytic activity and high stereoselectivity. However, phosphine ligands have a common disadvantage which is known as instability, so they are not easy to be stored. In order to solve this problem, we designed a new class of novel chiral ferrocenyldiphosphine ligands. The dissertation mainly focus on 3 aspects as follows:1. Acetylferrocene was prepared by Friedel-Crafts reaction from ferrocene and acetyl chloride. The asymmetric transfer hydrogenation (ATH) of acetylferrocene was carried out in presence of complex Ru~Ⅱ-(R,R)-TsDPEN) as catalyst. The product obtained by ATH was esterified, then followed by reacting with dimethylamine. The optical (R)-(+)-N,N-Dimethyl-1-ferrocenylethylamine was obtained in a total yield of 54.5%.2. A ligand with similar structrue to ChenPhos was synthesized. Its transition metal Rhodium complex was prepared according to synthetic route of ChenPhos. Catalytic activity and stereoselectivity were evalued by asymmetric hydrogenation of cinnamic acid derivatives.3. We selected 3 different configurations of 1,2-diphenylethanediol, that is (R,R)-, (S,S)- and DL-diphenylethanediol as the bridging groups and synthesized 3 corresponding novel ligands L3, L4, L5. Novel chiral phosphine ligands have multiple chiral centers and higher stability compared with other phosphine ligands. Absolute configuration was identified by XRD. Catalytic activity and stereoselectivity of its transition metal iridium complex were assessed by asymmetric hydrogenation of schiff base.