Visible Light Catalysis Synthesis Of Isoxazoline Derivatives

Isoxazolines and the corresponding unsaturated analogues,isoxazoles,that can be found in a plethora of complex natural products,drugs and in numerous molecules of biological importance,play an extremely important role.In the past few years,synthesis of isooxazolines and their derivatives via oxidative cyclization of unsaturated oximes using allyl oximes as free radical acceptors,the reaction strategies have achieved great progress.However,the traditional synthesis methods rely too much on metal-catalysts,and it is particularly important to develop greener and more economical methods to construct isoxazoline derivatives.Visible light catalytic system has been successfully applied to the synthesis of a variety of complex functional compounds,showing excellent catalytic synthesis value and industrial application potential.In this thesis,we studied the Visible light catalysis synthesis of isoxazoline derivatives.The main contents are as follows:1.A g-C3N4-based photocatalyst for visible light photocatalytic synthetic isovazoline reactionWith β,γ-unsaturated oxime as the substrate,By optimizing the reaction conditions,the optimal reaction conditions were determined as follows:under the conditions of purple light and oxygen,reactants 1(0.3 mmol),g-C3N4(20 mg),Cs2CO3(1.5 equiv)and solvent CH3CN/TFE=7:1(v/v,10 mL)to obtain the corresponding isoxazoline derivatives with moderate yield.The outstanding advantages of this method are wide substrate range,mild reaction conditions and green economy.2.Visible light photocatalytic synthetoxazoline reaction initiated via EDA complexWith β,γ-unsaturated oxime as the substrate,the optimal reaction conditions were determined by condition optimization as follows:under purple light and air conditions,reactant 1(0.3 mmol),KI(20 mol%),solvent CH3CN/TFE=7:1(v/v,10 mL),and the target product was obtained in good yield.It provides a simple and effective method for the synthesis of isoxazoline derivatives.