The Synthesis Of Novel Chiral Ferrocenylimidazoline Ligands And Their Application In Asymmetric Aza-Claisen Rearrangement

In past severl years, the synthesis and application of chiral imidazoline ligands has made great progress. First, the synthesis and application of chiral imidazoline ligands has been reviewed.Second, a novel and efficient approach to synthesize chiral ferrocen- ylimidozlines has been designed, which is shrot, efficient and easy opera- ting.And the yield of target compounds is above 50 %.Third, we first developed the enantiospecific synthesis of ferrocenyl- imidazoline compounds from optical amino alcohols,which has an impor- tant value in theory and application.And we first design and synthesize f- errocenylimidazoline palladacycle catalyst with planar and center chirali- ty, which make the investigation of ferrocenylimidazoline ligands more abroad.Fourth, In the process of exploring the synthesis route, Swern oxida- tion was successfully applied to synthesize amide aldehyde 9 in high yiel- d. Reduction of oxime using the cheap Al/Ni alloy and NaOH(aq) generate- d primary amine at room temperature in excellnet yield. The primary ami- ne was transformed into a variety of alk- and aryl- substituted sulfonami- des 11 which were proceeded in high yield (up to 99%) by treatment with DMAP (cat. equiv.).The ferrocenylimidazoline ligands could be obtained by dehydrateion. The reaction proceeds in high yield (> 90%) with excel- ent chemo- and enantiospecificty. In this novel route, 9-13, 15 and 16 are all new sollid compounds and are stable enough in air to be purified. All new shown were fully characterized (NMR, IR, HRMS) and give satifact- ory analytical.The new ferrocenylimidazoline ligand could be successfully ortho- Palladated , furnishing the palladacycle 15.And 15 was applied in the Aza–Claisen rearrangement, which could approve the catalytic activity of 15.