| Organic Photochemical synthesis is an important component of modern organic chemistry. After motivation by light the highly reactive intermediate compounds could realize the reactions that are difficult or impossible for conventional thermal reaction.Based on good biological activities, trifluoromethyl compounds have been widely used in the field of pharmaceutical chemistry, pesticides and chemical materials. At the same time, 1,6-alkenynyl compounds are very common in natural products. This dissertation mainly research the cycloaddition of 1,6-alkenynyl compounds through the chlorination and three fluorine methylation under visible light conditions.Under the heating conditions or irritating by light, cycloaddition reactions could generate cyclic compounds by addition reactions of double bonds among two or more unsaturated molecules. Cycloaddition reactions occupy an important position in modern organic synthesis for the extensive applications. Although the organic chemists have always focused on these studies, the cycloaddition reactions induced by the visible light are very novel synthetic methods.This dissertation designed a series of cycloaddition reactions between1,6-alkenynyl compounds and trifluoromethylsulfonyl chloride. By screening photosensitizers, solvents and light sources, the optimal reaction conditions were obtained: tris(2,2’-bipyridyl) ruthenium(II) chloride complex as catalyst, DMF as solvent, the reactions of 1,6-enyne compounds at a concentration of 0.0075 mol/L could give the highest yields under the light of 1W blue LED, and a series of chlorinated and trifluoromethylated cycloaddition products were synthesized with the reaction conditions. After determinating the chemical structures of the products by NMR and high resolution mass spectrometry. The dissertation speculated a plausible reaction mechanism based on the theoretical basis and reaction characteristics of trifluoromathanesulfonyl chloride under visible light conditions. The experimental method in this dissertation could give high yields with simple operations under mild conditions, and have good universality as well. At the same time, the synthetic products with good biological activities has been widely used in the field of medicine and pesticides.With utilizing organic photochemistry methods, the cycloadditions of 1,6 alkenynyl compounds gived the nitrogen-containing five-membered heterocyclic compounds in this dissertation. This method avoids the additions of complex metal catalysts and conventional synthetic methods in harsh conditions, providing a new approach for the synthesis of nitrogen-containing five-membered heterocyclic compounds. |
