Study On The Synthesis Of Diaryl Sulfones And Esters Via Visible Light-induced Reactions Of Sulfonamides With Boronic Acids

Amides are widely present in drugs,natural products,polymers and pesticides.Thedirect functionalization of amides has always been a difficult problem in organic synthesis.Recently,the cross-coupling reaction between amides and nucleophiles has attracted gre at attention.Most of works were catalyzed by transition metal via C-N bond cleavage of amides,then cross-coupling with various nucleophile regents to synthesize ketones,esters and other compounds.T hey have the advantages of controllability and high selectivity.In recent years,visible light-induced organic synthesis has been one of the most important areas in the field of organic synthesi s because of its mild,efficient and environmentally friendly characteristics.However,the transformation of sulfonamide induced by visible light has not been reported.Therefore,in this thesis,some research work has been carried out for the synthesis of diaryl sulfones and esters induced by visible light based on sulfonamides and boronic acids.The specific contents are divided into three parts as follows:1.In the first part,the research progress of coupling reactions for the synthesis of ketones,biphenyls,esters,amines and other compounds via highly selective cleavage C-N bond of amide is described.2.In the second part,a variety of diaryl sulfones with different substituents were synthesized by cross coupling of sulfonam ides with boronic acids induced by visible light.This reaction works in mild and transition-metal-free conditions,which offers a potential application for the synthesis of sulfone derivatives in pharmaceutical production.This method involves visible light-induced N-S bond cleavage rather than traditional transition metal-catalyzed C(O)bond cleavage,providing a new way for the modification of amides and sulfonamides.3.In the third part,a visible light-induced coupling of sulfonamides with boronic acids was studied,offering a new method for the synthesis of ester derivatives.Unlike the previous reported transition metal-catalyzed esterification reaction of most amides,this method realized the conversion of amides via visible-light excitation.This reaction provides a new mild,green,and environmentally friendly method for the esterification of sulfonamides.