The Study On The Synthesis And Reactivities Of Polysubstituted Vinyl Sulfones

In this thesis, we studied the carbozincation of acetylenic sulfones and the coupling reaction of the obtainedα-sulfonyl vinyl zinc reagents with halohydrocarbons in the presence of NiCl₂(PPh₃)₂. We also investigated Pd( II) catalyzed Sonogashira coupling reaction of terminal alkynes and (E)-β-iodovinyl sulfones. Polysubstituted vinyl sulfones were synthesized regio-and stereoselectively. The thesis consists of the following two parts:Polysubstituted vinyl sulfones were synthesized regio- and stereoselectively by the three-component tandem reaction of the zinc reagents, acetylenic sulfones and halohydrocarbons.α-Sulfonyl vinyl zinc reagents were prepared by the carbozincation reaction of acetylenic sulfones and benzyl zinc bromide, butyl zinc chloride or p-fluorobenyl zinc chloride. Polysubstituted vinyl sulfones were synthesized regio- and stereoselectively by the Negishi coupling reaction of the obtainedα-sulfonyl vinyl zinc reagents with halohydrocarbons in the presence of NiCl₂(PPh₃)₂. The molecular structures of products 4b and 4j were determined by X-ray diffraction analysis.Polysubstituted vinyl sulfones containing the structural unit of conjugated enyne were synthesized regio- and stereoselectively by Sonogashira coupling reaction of terminal alkynes and (E)-β-iodovinyl sulfones. Then we further investigated the cross-coupling reaction of polysubstituted vinyl sulfones containing the structural unit of conjugated enyne with Grignard reagent catalyzed by NiCl₂(PPh₃)₂. The methods have the advantages of easily available materials, simple manipulation and mild reaction conditions.