Studies On Coupling Reaction Of Acetvienic Sulfones With Acetylenic Grignard Reagents And Palladium-catalyzed Addition Of Allyl Halides To Acetylenic Ketones/Sulfones

In this paper, the coupling reaction of acetylenic sulfones withacetylenic Grignard reagents and the addition reaction of acetylenicsulfones or acetylenic ketones were investigated. A series ofunsymmetrical1,3-diynes were synthesized by desulfonylation couplingof acetylenic sulfones and acetylenic Grignard reagents. Polysubstitutedvinyl halides were obtained by Pd-catalyzed addition reaction ofacetylenic sulfones or acetylenic ketones. The obtained polysubstitutedvinyl halides were further transformed to polysubstituted alkenes orbenzenes by Suzuki coupling reaction or Sonogashira coupling reaction.The thesis consists of the following three parts:Firstly, we studied the Ni（acac）₂-catalyzed desulfonylation couplingreaction of acetylenic sulfones and acetylenic Grignard reagents. A seriesof unsymmetrical1,3-diynes were synthesized by the Ni（acac）₂-catalyzeddesulfonylation coupling reaction. The reaction has the advantages ofhigh selectivity and without homocoupling byporoducts. All productswere characterized by1H NMR,13C NMR, IR and HRMS.Secondly, we studied PdCl2-catalyzed addition reaction of acetylenicketones or acetylenic sulfones with allyl halides. A series ofpolysubstituted vinyl halides containing sulfonyl or carbonyl group weresynthesized in high regio-and stereoselectivity. The obtained vinylchlorides were further transformed to polysubstituted alkenes bySuzuki-coupling reaction. All products were characterized by1H NMR,13C NMR, IR and HRMS. The molecular structure of compound8b wasconfirmed by X-ray diffraction analysis, which shows that the addition ofallyl chloride to acetylenic sulfone is in syn-fashion and chloro is addedto the β-posotion of sulfonyl. Lastly, we studied the tandem Sonogashira coupling-cyclizationreaction of vinyl halides and terminal alkynes. Polysubstituted benzeneswere synthesized by Pd（OAc）₂-catalyzed tandem Sonogashiracoupling-cyclization reaction of β-sulfonyl vinyl chlorides or β-carbonylvinyl bromides and terminal alkynes. All products were characterized by1H NMR,13C NMR, IR and HRMS. The molecular structure ofcompound14a was characterized by X-ray diffraction analysis.The research results provided new methods to synthesizeunsymmetrical1,3-diynes, polysubstituted alkenes and polysubstitutedbenzenes. The methods have the advantages of easily available startingmaterials and simple operation.