Selective Sulfurization Of Inert Csp~3-H Bonds Based On Light-promoted Copper Catalysis

The sulfur containing compounds have been attracted a great deeply attention,due to the great potential activities of sulfur compounds in new medicine,agriculture and functionalized chemical reagents.The oranosulfides,which are commonly existed in both natural and unnatural products,have inhibitory effects on cancer,HIV,alzheimer' sdisease,inflammation,and asthma.And also these compounds are essential in the field of materials,because they can improve the physical,electronic and surface properties of materials.Based on the importance of organic sulfur compounds,herein,we have developed a method of combining visible light and transition metal for the synthesis of various aryl thioethers.In this paper,initially,the utility and the importance of various organic sulfur compounds are reviewed.And then,the advantages and disadvantages of the methods to construct C-S bond were summarized.Finally,it is concluded that the direct functionalization of inert Csp3-H bond is a simple,efficient and rapid method to construct complex molecules.However,due to its diversity and low reactivity,it is a very challenging research topic to selectively realize the direct functionalization of inert Csp3-H bonds.The hydrocarbon bond activation of alkanes induced by free radicals is a very attractive research direction.The selective functionalization of inert Csp3-H bonds can be realized by radical transfer.This research,N-fluoro-tosylamide and phenyl disulfide were selected as the reaction substrates,the site-selective thiolation of remote C-H bonds of saturated alkane was successfully realized via extensive optimization of catalysts,solvents,additives and so on.This method have broad substrates scope and good selectivity.At the same time,the late-stage modification of amino acid derivatives and steroids with biological active compounds by this method was also demonstrated.The competition experiment between different C-H bonds were carried out independently to compare reactivity and selectivity.Even more important,a type of chain amides substrates by cyclization and sequence thiolation,affording thiol substituted pyrrolidine or piperidine derivatives.Finally,the radical process was demonstrated by the results of radical clock reactions,competition experiments and control experiments.