Study On The Synthesis Of 2,5-Disubstituted Oxazoles And Indenones Derivatives

Oxazoles and indenones play an important role in nature,and they are prevalently used in natural product,pharmaceutical,biochemistry and materials science.They are important structural scaffolds in a great number of pharmaceuticals and biologically active molecules,and many oxazoles and indenones derivatives have excellent effects in the treatment of some diseases such as anti-cancer,anti-diabetes,bactericidal,anti-inflammatory,and are also used in agriculture as various insecticides.Moreover,they are also versatile intermediates in the synthesis of some natural products such as steroids and gibberellins.Oxazoles and indenones have been the focus of chemists for their unique biopharmacological activities,so it is important to study novel and effective synthetic methods for such compounds.The first chapter of this thesis mainly describes the specific application of oxazoles derivatives and indenones derivatives in pharmaceutical,materials and pesticides.It also summarizes the synthetic methods of these compounds reported in the literature over these years.Homogeneous gold catalysis is increasingly used in the field of organic synthestic field.However,there are few reports on the combination of gold catalysis and radical reaction.The only few reports on gold catalysis-radical reaction catalyzed N-propargyl amide or other types of gold-catalyzed N-propargyl amide are concentrated in the study of terminal alkynes.As for the method of synthesizing oxazoles under the conditions of gold catalysis and radical reaction for the internal N-propargyl amides has been unexploited.The research content in the second chapter of this thesis mainly introduces a new gold catalysis-radical reaction system that we developed,and the catalytic oxidation of an internal alkyne-type N-propargyl amide was successfully carried out to form a 5-acyloxazole compounds.The method has the advantages of mild conditions,good compatibility of functional groups and amplification to a gram-scale reaction.In addition,in the third chapter,another new strategy is introduced,catalytic oxidation of ortho-phenylacetylene substituted N-propargyl amide substrates in a gold catalysis-radical system to form oxazole rings and indenone structures in one step,resulting in a series of new 3-oxazolyl indenone derivatives.This type of products has great potential application research value.