Recent Advances in Ullmann Reaction:Copper ( II ) Diacetate C at alysed N - ,O - and S - ArylationInvolving Polycoordinate Hetero atomic Derivatives

Copper-catalyzed O- and N-arylation reactions involving triarylbismuth diacetates or aryllead triacetates are ligand coupling reactions which were discovered in the eighties independently by Barton's and Dodonov's groups. These reagents lead generally to efficient arylation under mild neutral conditions (room temperature or 40 dgree C, no added basic reagent). Recently, the scope of these main group metal mediated reactions was broadened when Chan and Evans reported that organoboron compounds can be used as the source of the organic aryl ligand. Subsequently, organosiloxanes, organostannanes and diaryliodonium salts proved also to be efficient reagents for these mild copper catalyzed O- and N-arylation reactions. Organoantimony compounds were also used but appeared to be less efficient reagents.