Chemoselective Copper-Catalyzed Ullmann-Type Coupling of Oxazolidinones with Bromoiodoarenes.

We describe the highly selective copper-catalyzed Ullmann-type coupling of bromoiodoarenes with oxazolidinones. 3,4,7,8-Tetramethyl-1,10-phenanthroline (Me4 Phen) was identified as an optimal ligand promoting the desired C-N bond formation, while minimizing the competitive bromo-iodo exchange pathway that leads to formation of iodo-substituted and bis-coupled side products. The developed method is highly selective with a >98:2 ratio of the bromo- vs iodo-substituted compounds obtained in the isolated products.