Study On The Selective Click Chemistry Of Fluoroalkyl Alkynes

The strong electronegativity of fluorine atoms and the relatively small radius of physicochemical properties,so organic fluorine chemistry is widely used in various fields such as synthetic chemistry,drug development,and material chemistry.In this paper,a click reaction of fluoroalkyl alkyne compounds and organic azides is carried out to effectively obtain a class of 4-fluoroalkylated 1,2,3-triazole derivatives.The work content of this paper is as follows.This paper first optimized the conditions for the click chemistry reaction of fluoroalkylalkynes,that is:fluoroalkylalkynes and equivalent azide compounds in DMF,at 60℃with 5mol%Cp*Ru Cl（PPh₃）₂ catalyzed reaction 12 Within hours,a single-configuration 4-fluoroalkyl 1,2,3-triazole derivative can be obtained efficiently and selectively.The absolute configuration is confirmed by single crystal diffraction of compound 6lg.Subsequently,under the optimal conditions,the fluoroalkyl alkyne and azide compounds with different substituents were studied respectively,and 46 novel 4-fluoroalkyl groups with a separation yield of 70-98%were obtained.1,2,3-triazole derivatives further show that the reaction has excellent yield and good functional group tolerance.This thesis further explored the selectivity of click chemistry reactions between fluoroalkyl alkynes and terminal alkynes,as well as phenyl azide and benzyl azide.In the copper salt catalytic system,the 1,3-dipolar cyclization of azide compound and terminal alkyne has high efficiency and selectivity,while azide compound and fluoroalkyl alkyne have a conversion rate of 5%under the same conditions;In the catalytic system of the complex,benzyl azide and alkyl azide can perform click reactions with fluoroalkyl alkyne,while the conversion rate of phenyl azide and fluoroalkyl alkyne is only 3%under the same conditions.This design synthesizes di-alkynes 4a containing fluoroalkyl alkynes and terminal alkynes.Under the action of copper catalyst,phenyl azide reacts with 4a terminal alkynes with high selectivity to obtain a single configuration of 1,4-substituted alkyne.The yield of triazole 5a is 93.7%;then under the catalysis of ruthenium,the benzyl azide reacts with the fluoroalkyl alkyne of 5a to obtain 7a with a yield of 74.8%.