Unsymmetrical Diaryliodonium Salts : Development and Chemoselectivity studies

Abstract: The first part describes a chemoselectivity study on diaryliodonium salts where oxygen, nitrogen and carbon nucleophiles have been arylated. Twelve different unsymmetric phenyl(aryl)iodonium salts were designed with a systematic variation of the steric and electronic properties of the aryl group. The chemoselectivity varies greatly between the nucleophiles but several “dummy” aryl groups were identified where selective transfer of the phenyl moiety was consequently observed. HRMS studies of the salts revealed an interesting ligand exchange between the aryl groups of the iodine under certain conditions. This will aid the understanding of the mechanism operating in diaryliodonium salt arylation reactions. The results will facilitate the design of catalytic systems employing diaryliodonium salts, as well as help in search for applications with polymer-bound salts.The second part of the thesis describes the development of a new synthetic route towards unsymmetric diaryliodonium salts containing one heteroaryl moiety. The substrate scope of the facile one-pot protocol involves salts containing dummy groups with large steric bulk as well as electron-rich aryl groups. The utility of the salts are demonstrated in the arylation of both phenols and malonates where selective transfer of the heteroaryl moiety was consistently observed