Study On Halogenation Addition Reaction Of Carbon Carbon Unsaturated Bonds

Organic halides are not only widely used in pharmaceutical chemistry,material chemistry and other fields,but also important synthetic intermediates in organic chemistry.Therefore,the preparation of halogenated compounds has received extensive attention in organic synthesis.In this thesis,alkynes and alkenes are employed as reaction substrates to afford a series of organic halides with high regioselectivity under mild conditions.The details are as follows:（1）In this thesis,phenylacetylene was used as the template reaction via TMSOTf as the additive to optimize a series of reaction conditions,such as metal catalyst,TMSOTf dosage,halogen source,reaction time and reaction temperature.In this catalytic system,the expected martensitic addition product can be obtained with high yield by changing the amount of TMSOTf.Alkynes（1.0 mmol）,[Ru Cl₂（p-cymene）]₂（3.0 mol%）,TMSOTf（0.5 equiv）,H₂O（2.0 equiv）and KI（1.2 equiv）were employed in DCE（3.0 m L）for 12 h at 70℃to afford corresponding vinyl iodides.When KI is replaced by Zn Br₂ or Zn Cl₂,and the amount of TMSOTf is increased to 0.65 equiv,vinyl bromides and vinyl chlorides can be generated.Based on the result of control experiment,we found that the halogen source come from metal halides and the hydrogen source come from water.Finally,hydrohalogenation reaction of alkynes was achieved in 42%to 97%yield,and alkenyl chloride,bromide iodine compounds were obtained under the joint action of ruthenium catalyst and TMSOTf additive.（2）In this thesis,1-phenyl-2-（trimethylsilyl）acetylene was employed as template reaction.A series of reaction conditions were optimized,such as halogen source,solvent,substrates ratio,reaction temperature.In synthestic system ofα,α,α-trifluoroaryl ketone,Selectfluor is the catalyst and fluorine source in the reaction.Silicon alkyne（1.0 mmol）and Selectfluor（3.1 equiv）can be obtained in CH₃CN/H₂O（2/1,3.0 m L）at 90℃for 24 hours,which gaveα,α,α-trifluoroaryl ketone compounds in 32%to 95%yield;In preparation forα,α,α-difluoro monochloroaryl ketone compounds,silicon alkyne（1.0 mmol）,SelectfluorⅡ（3.1equiv）and Na Cl（2.0 equiv）was employed in CF₃CH₂OH/H₂O（2/1,3.0 m L）at 70℃for 24hours,and the yield is 28%to 76%was obtained.（3）In this thesis,we employed styrene as template reaction,a series of reaction conditions were optimized,such as catalyst,halogen source,reaction time,reaction temperature and solvent.In this synthetic system,by using Cu Cl₂（2.5 mol%）as catalyst,NCS,NBS and NIS（1.0 equiv）as halogen sources,and different proton solvents,highly selectiveβ-haloether,β-haloeaters andβ-halohydrins can be achieved.Finally,various alkyl halides with high selectivity were obtained in 52% to 99% yield.