Synthesis Of Chiral S, P-Ligands Derived From Ferrocene And Application In Asymmetric Hydrogenation Of Quinolines

Chiral S,P-ligands derived from ferrocene were synthesized. The application of these chiral ligands in asymmetric hydrogenation of quinolines was carried out, and the role of planar chirality was also examined.i) Synthesis of chiral S,P-ligands derived from ferrocene and application in asymmetric hydrogenation of quinolinesUsing commercially available (S)-1 as the starting material, the chiral S,P- ferrocenyl ligands 3a-3f were synthesized according to the known method. To study the effect of steric hinderance in Cp ring on activity and enantioselectivity, ligand 5 with TMS group in Cp ring of ligand (S,Rp)-3 was synthesized. To explore the role of planar chirality on the enantioselectivity and absolute configuration of the products, ligands 7, 8 with same central chirality and reversal planar chirality were also synthesized from the same starting material (S)-1.Iridium complexes with S,P-ligands showed good activity and enantioselectivity for asymmetric hydrogenation of quinolines. The planar chirality played an important role in the reaction, (S)-central chirality and (Rp)-planar chirality is matched. When a bulky TMS group was introduced to Cp ring, two ligands 5,7 with the same central chirality and reversal planar chirality gave the desirable products with high enantioselectivities and reversal absolute configurations. Furthermore, both enantiomers of 1,2,3,4-tetrahydroquinoline derivatives were obtained using the same chiral starting material derived two...