Studies On The Asymmetric Addition Reactions Of Terminal Alkynes To Imines And Aldehydes

This thesis is composed of three parts:(1) The asymmetric addition reactions of nucleophilic acetylides to carbonyl groups and imines are important processes in organic synthesis.In this part,the development of these reactions is illustrated from its very beginning up to the present.The reactions are classified by their electrophiles,and introduced systematically.(2) We have developed the asymmetric addition reactions of nucleophilic acetylides toα-amino N-tert-butanesulfinimines,which were synthesized from L-amino acids.The desiredα-(dibenzylamino) propargyl amines orα-(phthaloyl-imide) propargyl amines were obtained in high yields and good distereoselectivities(95:5 to＞99:1 dr) under optimized conditions.Removal of the phthalimide group afforded the propargyl diamines, which could be cyclized to chiral pyrroline in the presence of Au(Ⅲ).(3) Three new chiralβ-hydroxy amide ligands were synthesized via the reaction of benzyl chloride and amino alcohols derived from L-tyrosine.The titanium(Ⅳ) complex of chiral ligand,which is synthesized from 2-amino-1-(4-(benzyloxy)phenyl)-3-ethyl-pentan -3-ol,was found to be an effective catalyst for the asymmetric alkynylation of aliphatic,vinyl and aromatic aldehydes.The propargyl alcohols were obtained in highly enantiomeric excesses(up to 96%ee) under optimized conditions.