Synthesis And Photoreactions Of 4-trifluoromethylquinoneol Oxime Ester

Oxime esters are a special class of imines,which are widely used in organic synthesis due to their high reactivity.The N-O bond of oxime ester is easy to break to form imine radical,making it to be the main precursor of imine radical.Imine radical is a unique nitrogen-centered radical,which can be used for the synthesis of various nitrogen-containing natural products,drugs and bioactive molecules.Oxime esters can generate imine radicals under various reaction conditions,such as ultraviolet light,visible light induction or transition metal catalysis.Among them,the reaction induced by visible light is the most green and environmentally friendly,which is of great significance for the development of green organic chemistry.Easily-available p-quinols are widely existed in various drugs and natural products and with versatile reaction sites.Our research group has been dealing with the reactions of p-quinols for a long time.With transition metals and Lewis acids/bases as catalysts,we have developed a variety of efficient multi-component reactions and synthesized a variety of poly-substituted arenes.To explore more green and efficient reaction modes for quinols,especially the applications of radical type reaction is our main goal in the near future.Therefore,in this thesis,the synthesis of quinol oxime ester and its radical-type reactions induced by visible light were explored by combining quinols with oxime ester.It may expand a new reaction mode of quinols.The following parts of work were mainly researched:（1）The optimization of reaction conditions for the synthesis of 4-trifluoromethylquinol oxime ester and their optical properties were studied;（2）With iridium complex as the photosensitizer,a series of aliphatic long-chain substituted trifluoromethyl arylamines were synthesized by the three-component reactions of4-trifluoromethylquinol oxime ester,methyl acrylate and diisopropylethylamine（i Pr₂NEt）induced by visible light.The advantages of this reaction are green and highly efficient,as well as that the use of acid or base or transition metal catalyst is avoided.（3）With iridium complex as the photosensitizer,the C-N coupling reactions of4-trifluoromethylquinol oxime ester with N-phenyl tetrahydroisoquinoline were explored under visible light induction.A series ofα-imino-substituted tetrahydroisoquinoline were synthesized.The efficient C-N coupling reaction was realized under mild conditions without adding any additional oxidant.（4）The reaction mechanisms of above two kinds of reactions were studied in detail.The results showed that both reactions experienced the imine radical as the important radical intermediate.In this paper,36 new compounds were successfully synthesized and characterized by¹H-NMR,¹³C-NMR,¹⁹F-NMR and high-resolution mass spectrometry.The structure of some compounds was further confirmed and analyzed by single crystal X-ray diffraction experiment.