Chiral Biscarboline N,N’-oxide Derivatives Catalyzed Asymmetric Reduction Of Ketoimines With And Symmetric Cyanation Reactions

Chiral amines and cyanohydrins are well-known natural products and they have beenwidely used as intermediates for pharmaceutical, agro-chemicals and additive chemistry.Therefore, the development of straightforward synthetic procedures for such compounds,which also result in a high degree of stereoselectivity, has prime importance in chemicalindustry. This thesis which gives a preliminary study with the two compounds containsmainly three chapters.Chapter one reviewed the asymmetric reduction of ketomines which HSiCl3playes as areduction regent with various catalysts. And, all their applications are also investigated.The chapter two is based on our previous work. We continue to explore the axially chiralbicarboline-N, N′-dioxide which were synthesized with amide in position C-3,C-3′for theasymmetric reduction of ketimines with trichlorosilane. As the results showed, the reductionof ketimines with the catalyst at0℃was successfully accomplished in16h, leading to thecorresponding saturated compound in high yield(>99%). And the substrates with electrondonating substituent at aromatic ring afford a better performance, giving the bestenantionselectivity with85%ee. However, amides N-Oxides owing cyclic amides at the C-3and C-3′positions exhibited moderate to high enantioselectivity. The catalyst containedpyperidine moiety presented the best result.On the basis of the asymmetric cayantion reaction we summarized in chapter three, weinvestigated this kind of reaction with the axially chiral bicarboline-N, N′-dioxide. Unluckily,we found no reaction activity with ester and amide group in position C-3and C-3′. Then, wescreened the complexes which were formed by the catalysts and8kind of metal includingTi(iOPr)4. The yield has been significantly improved (<50%), but showed noenantioselectivity. The catalysts require further modification.