Copper-catalyzed Selective Synthesis Of Di -and Triarylamines

Di-and triarylamines are important building blocks in dyes, pharmaceuticals and photoelectric function materials. As one of the traditional methods to assemble these compounds, Ullmann reaction is limited by the harsh reaction condition, substrate scope and the moderate yield. Recently, much attention has been paid on Cu-catalyzed formation of C-N bonds.In our previous work, we found o-aminophenol derivatives promoting Cu-catalyzed C-N bond formation. In further investigation, o-aminophenol could couple with iodobenzene in the Cu-catalyzed system without ligand which indicated their self-accelerating effect.In this thesis, by investigating the effect facts in the reaction of o-aminophenol and aryl halides, such as copper, base, solvent and molar ratio of raw materials, we developed a ligand free system for selective N-arylation and N,N-diarylation. With the optimal reaction condition of N-arylation, o-aminophenol coupled with aryl halides to get diarylamines in 63-92%yields. The reaction also showed favorable functional group tolerance, such as methyl, methoxyl, acetyl, nitro, especially free hydroxyl and amine group. The different reactivity between iodides and bromides allowed us to obtain the 2-(4-bromophenyl-amino) phenol selectively. With the optimal reaction condition of N,N-diarylation, triarylamines could be obtain in the yield of 46-87%. Compared with N-arylation, the steric effect of N,N-diarylation was significant.When o-aminophenol coupled with p-nitro aryl halides, N-arylation product and O-arylation product were obtained simultaneously. By investigating the reaction conditions, o-aminophenol could transforme to N-or Oarylation product selectively.The results of further investigations indicated that self-accelerating effect occured in the condition of hydroxyl and amino group in ortho position.Utilizing the dramatic self-accelerating effect of o-aminophenols, we developed a Cu-catalyzed system for the selective synthesizing di-and triarylamines. In addition, the N-and O-arylation products of o-aminophenol could be obtained when nitro aryl halides severed as substrates.