Synthesis Of (E)-α-stannylvinyl Sulfides And Their Applications In Highly Selective Synthetic Reactions

Content: this dissertation describles the stereoselective synthesis of 1,1-difunctional group reagents (E)-α-stannylvinylsulfides and their applications in organic synthesis.The palladium-catalyzed hydrostannylation of acetylenic sulfides with tributyltin hydride gives versatile (E)-α-stannylvinylsulfides . (E)-α-Stannylvinylsulfides are new difunctional group reagents. We carried out the cross-coupling reaction of (E)-α-stannylvinylsulfides with alkenyl halides in the presence of Pd(PPh₃)₄/CuI, to afford the correponding 1,3-dienyl sulfides in high yields. Based on the different reactivities of arylsulfanyl and tributylstannyl groups, (E)-α-stannylvinylsulfides can undergo the sequential cross coupling reactions with electrophiles and nucleophiles in the presence of transition metal complexes to form two carbon-barbon bonds in the same olefmic carbon and allow the synthesis of trisubstituted alkenes stereoselectively. By iododestannylation, stereodefined (E)-α-iodovinyl sulfides have been synthesized, which reacts with terminal alkynes to provide one pot synthesis of 1,3-enynyl sulfides. (E)-α-Stannylvinylsulfides underwent palladium-catalyzed coupling reaction with allylic bromides to give 1,4-dienylsulfides in good yields.We examined the generation of vinyllithium by the tin-lithium exchange reaction of (E)-α-stannylvinylsulfides with n-BuLi, followed by trapping with aldehydes or ketones successfully leading to 2-arylsulfanyl substituted allyic alcohols.