Studies On The Asymmetric Addition Reactions Of Chiral α,β-Unsaturated-N-tert-Butanesulfinyl Ketimines

This dissertation focuses mainly on the regio- and diastereoselective addition reactions of chiral α,β-unsaturated-N-tert-butanesulfinyl ketimines. The dissertation consists of three chapters:(1) Studies on the regio-and diastereoselective addition of Grignard reagents to chiral fluoroalkyl α,β-unsaturated-N-tert-butanesulfinyl ketimines; (2) Studies on the regio-and diastereoselective addition of organolithium reagents to chiral fluoroalkyl α,β-unsaturated-N-tert-butanesulfinyl ketimines; (3) Studies on the asymmetric trifluoromethylation of chiral α,β-unsaturated-N-tert-butanesulfinyl ketimines.In chapter 1, the addition reaction of Grignard reagents to chiral fluoroalkyl α,β-unsaturated-N-tert-butanesulfinyl ketimines was studied. The addition reaction proceeds mainly in a 1,4-addition manner, affording the corresponding fluoroalkyl-substituted β-chiral N-tert-butanesulfinyl enamines in good yields and with excellent diastereoselectivities. The fluoroalkylated ketones and amines with β-stereocenter could be obtained in high enantiomeric purity by further trasformation of the adducts.In chapter 2, highly regio- and diastereoselective 1,2-addition of organolithium reagents to chiral fluoroalkyl α,β-unsaturated-N-tert-butanesulfinyl ketimines was developed, providing a general and efficient method for the asymmetric synthesis of α-tertiary fluoroalkyl allylic amines in high yields and with excellent diastereoselectivities without any additives. The synthetic application of the method was demonstrated by the rapid and convenient preparation of challenging α-fluoroalkyl α-amino acids with α-tetrasubstituted carbon.In chapter 3, the regio-and diastereoselective asymmetric trifluoromethylation of chiral α,β-unsaturated-N-tert-butanesulfinyl ketimines was achieved using Ruppert-Prakash reagent as CF3 source and CsF as desilyting reagent, providing a novel method for the asymmetric synthesis of a-tertiary trifluoromethyl allylic amines.