Synthesis Of Phenols And Diaryl Ethers Based On Diaryliodonium Salts

Diaryl iodonium salt is a kind of arylation reagent which is insensitive to heat and humidity and has high reaction activity.It consists of two aromatic rings connected to a trivalent iodine positive ion.It can react with carbon,nitrogen,oxygen,sulfur,phosphorus,selenium and other atoms to obtain corresponding aromatization products.At present,the research reports on diaryl iodonium salts mainly focus on the construction of chemical bonds such as C-C and C-N,while the research on C-O is relatively few.Phenols play an important role in drug synthesis.The hydroxylation of aryl halides is a common method for the synthesis of phenols,which is usually conducted under harsh conditions such as strong base,high temperature and special hydroxyl reagents.Therefore,the method for the synthesis of phenols using cheap and easily available hydroxyl reagents,under mild conditions,needs to be further explored.In addition,the coupling reaction between diaryl iodonium salts and water is rarely reported so far.It is assumed that this kind of reaction under mildconditions will be a new method for the synthesis of phenols.The use of water as hydroxyl reagent is not common in previous reports,which has certain innovative and green chemical significance.In this paper,the reaction of diaryl iodonium salts with water to synthesize aryl phenols and aryl ethers was studied.The specific work is as follows:The optimum reaction conditions for the synthesis of aryl phenols based on diaryl iodonium salts were obtained by screening the catalysts,bases,solvents and temperatures.Under the optimum conditions,the functional group tolerance of this reaction condition was further investigated,and the target product was obtained in a medium to high yield.An one-pot synthesis of diaryl ethers from linear diaryl iodonium salts was designed.In the hydroxylation of diaryl iodonium salts described in Chapter 2,an equivalent of aryl iodide is generated and discarded as waste,which is not conducive to atomic economy.Therefore,on the basis of the established reaction conditions for the synthesis of aryl phenols,we further optimized the reaction system.Without separating aryl phenols,a series of diaryl ethers were synthesized by one-pot operation,which fully utilized the two aryl parts of iodonium salts.In a word,based on the theoretical basis of high valence iodinechemistry,the aromatization of water by diaryl iodonium salts catalyzed by monovalent copper was systematically discussed in this paper.