Construction Of Flavonoids Containing Sulfur And Selenium Derivatives

C-S bond and C-Se bond are widely used covalent bonds in organic compounds.Compounds with such chemical bonds play a very important role in many fields such as biomaterials,biomedicine,and chemistry.Due to its wide application and potential biomedical value,the construction of sulfur-containing compounds and selenium-containing compounds has always been a hot field.Looking for different and better construction methods is currently the main research topic.Flavonoids are a class of small-molecule compounds with a wide range of biological activities.They have good biological activities such as anti-cancer,antioxidant,anti-inflammatory,and anti-microbial.Constructing a series of flavonoid derivatives,optimizing the construction methods of flavonoid derivatives and exploring their biological activities are the main research topics for flavonoid compounds.The construction of flavonoid sulfur-containing derivatives and selenium-containing derivatives is an important part of the construction of flavonoid derivatives.Previous research mainly used organic sulfides and organic selenides to construct flavonoid sulfur and selenium derivatives.Although these methods are simple in operation and convenient in conditions,it is necessary to first construct organic sulfides and organic selenides with strong reactivity,which increases the reaction steps,resulting in the disadvantages of cumbersome steps,not being green and environmentally friendly.Based on the previous research,this paper carried out condition improvement and optimization,and found a method to directly use inorganic sulfur and inorganic selenium to construct flavonoid sulfur and selenium compounds.(1)Elemental sulfur and potassium thiocyanate are used as inorganic sulfur sources,flavonoids are used as substrates,and aryl halides are used as benzene sources.One-pot method is used to construct flavonoid sulfur derivatives.The three components are reacted under the catalysis of copper ions for 16 hours to obtain a series of flavonoid sulfur derivatives with high yield.Compared with the constructionof flavonoid sulfur derivatives by organic sulfides,this method realizes the direct construction of flavonoid sulfur derivatives by inorganic sulfides.The method has simple and easy raw materials,the method is simple and easy to operate,and is environmentally friendly.(2)Elemental selenium and potassium selenium cyanate are used as inorganic selenium sources,flavonoids are used as substrates,and aryl halides are used as benzene sources.One-pot method is used to construct flavonoid selenium compounds.Using N’N-dimethylformamide as the solvent,under the catalysis of copper ions,the one-step synthesis of flavonoids containing selenium derivatives was completed.This method also has the advantages of easy availability of raw materials,simple method and environmental friendliness.At the same time,it greatly enriches the construction of flavonoid selenium compounds.This thesis successfully explored the one-pot method of constructing flavonoid sulfur-containing selenium derivatives with inorganic sulfur and inorganic selenium as sulfur and selenium sources,and successfully completed the flavonoid sulfur-containing selenium derivatives To inorganic sulfur source and inorganic selenium source.Pioneered a new method for constructing flavonoids containing sulfur and selenium derivatives,and added new reaction ideas for synthetic methodology.At the same time,under the explored reaction conditions,a series of sulfur-and selenium-containing derivatives were synthesized in this thesis.These compounds provide a broad range of substrate molecules for activity screening.At the same time,it also provides a reference method for the construction of sulfur-and selenium-containing derivatives of other natural products.All synthetic flavonoid derivatives have been verified by nuclear magnetic resonance hydrogen spectroscopy,carbon spectroscopy,infrared and high resolution.