Studies On The Asymmetric Reactions Of ?,?-Unsaturated Imines Derived From Chiral N-tert-Butanesulfinyl Amide

This dissertation focuses mainly on the studies of the asymmetric addition reactions of?,?-unsaturated imines derived from chiral N-tert-butanesulfinyl amide.It consists of two chapters:(1)Studies on the regio-and diastereoselective asymmetric Reformatsky reactions of ?,?-unsaturated imines derived from chiral N-tert-butanesulfinyl amide;(2)Studies on the regio-and diastereoselective addition reactions of organometallic reagents to ?,?-unsaturated ketimines derived from chiral N-tert-butanesulfinyl amide.In chapter one,the asymmetric Reformatsky reactions of fluoroalkylated ?,?-unsaturated ketimines derived from chiral N-tert-butanesulfinyl amide were firstly investigated.The results indicated that this reaction proceeds mainly in 1,2-addition manner,affording the corresponding ?-fluoroalkyl ?-vinyl ?-amino esters with a ?-tetrasubstituted stereogenic carbon center in good yields and with excellent diastereoselectivities.Then,the asymmetric Reformatsky reactions of ?,?-unsaturated aldimines derived from chiral N-tert-butanesulfinyl amide with ethyl bromodifluoroacetate were next studied.Also,the reaction proceeded only in 1,2-addition manner,furnishing the corresponding ?-vinyl ?,?-difluoro-?-amino esters in good yields and with excellent diastereoselectivities.In chapter two,the asymmetric addition reactions of organometallic reagents to?,?-unsaturated ketimines derived from chiral N-tert-butanesulfinyl amide were systematically investigated.The results showed that the addition of Grignard reagents to chiral ?,?-unsaturated-N-tert-butanesulfinyl ketimines proceeds solely in a 1,4-addition manner,while the addition of the organolithium reagents proceeds in a 1,2-addition manner.Further transformation of the adducts provides a highly efficient method for the synthesis of either enantiomer of ?-chiral ketones and chiral allylic amines bearing ?-tetrasubstituted stereogenic carbon center.