Catalyzed Coupling of Arylamines

Concurrent with this work, Goodbrand showed that the N-arylation of diarylamines in the presence of a catalyst consisting of CuCl and 1,10-phenanthroline occurred under milder conditions than had commonly been used previously for Ullmann chemistry (Equation 9.99)P In addition, reactions to form triarylamines from various aryl iodides and aromatic amines catalyzed by Cu(I) complexes, such as Cu(phen)(PPh3)Br and Cu(neocup) (PPh3)Br, which are soluble in organic solvents, were reported.  

A few reactions of aryl chlorides catalyzed by ligated copper complexes have been reported. The reaction of phenyl chloride with diphenylamine to form triarylamines catalyzed by the complexes of CuL(PPh3)Br in which L is 1,10-phenanthroline, neocuproine, or 2,2 -bipyridine occurred in about 50% yield. The favorable effect of potentially coordinating ortho substituents on the rates of Ullmann reactions has been exploited to couple o-chlorobenzoic acids with anilines to form N-arylanthranilic acids in aqueous or DMF solutions in the presence of pyridine.  

---