Studies On The Strecker Reactions Of R-tert-butanesulfyl α,β-unsaturated Trifluoromethyl Ketimines And Synthesis Of Unsymmetric NFSI Analogues

There are two parts in this thesis.The stereoselectivity of the reaction of (Rs)-trifluoromethyl α,β-unsaturated N-tert-butanesulfinyl ketimines with TMSCN was studied. The diastereomers of a-trifluoromethyl unsaturated cyano amines were obtained, respectively, in good yields with excellent diastereoselectivities in terms of the different solvents used. In c-hexane, the (R, Rs)-isomer was obtained with up to17:1dr, whereas the (S, Rs)-isomer was generated as the main product with up to145:1dr in DMF at-60℃. A solvent controlled high stereoselective asymmetric Strecker reaction of trifluoromethyl α,β-unsaturated N-tert-butanesulfinyl ketimines with TMSCN was realized. The diastereoselectivity of the Strecker reaction of unsaturated ketimine with TMSCN could be more facilely controlled by the solvents used. The reaction in c-hexane predominately afforded (R, Rs)-isomer5, whereas the (S, Rs)-isomer4was furnished as the major product while using DMF as the solvent. In the case of3b and3c in DMF, the isomer (S, Rs)-4b and (S, Rs)-4c were obtained with143:1and145:1dr, respectively, which is better than the reported saturated ketimine. This study would provide a new and efficient method for the preparation of novel α,β-unsaturated a-trifluoromethylated amine derivatives.The second of this thesis studied the fluorination reaction of unsymmetric benzenesulfonimides with diluted elemental fluorine to synthesize unsymmetric N-fluoro-benzenesulfonimide (NFSI) analogues. Several synthetic methods were compared and we found that, for many unsymmetric benzenesulfonimides, the fluorination of their sodium salts with10%F2/N2mixed gas in acetonitrile at room temperature could afford unsymmetric NFSI analogues in moderate to good yields.