Abstract
A simple, general, and highly efficient Betti base ligand has been developed for copper-catalyzed Ullmann coupling of phenol with aryl halides without the protection of an inert atmosphere. The reaction proceeds smoothly in the presence of K2CO3 as the base and dimethylsulfoxide as the solvent. The catalyst was reused several times with no evident loss of catalytic activity and is environmentally friendly.
GRAPHICAL ABSTRACT
Notes
a Reaction conditions: iodobenzene (1.0 mmol), m-cresol (1.0 mmol), CuX (0.1 mmol), L (0.2 mmol), 2.0 equiv base, solvent (3 mL), 120 °C.
b GC yield determined by using methoxybenzene as internal standard.
c Reaction temperature is 80 °C.
d Without L.
a Reaction conditions: iodobenzene (1.0 mmol), phenol (1.0 mmol), CuI (0.1 mmol), L1 (0.2 mmol), 2.0 equiv K2CO3, DMSO (3 mL), 120 °C. b Isolated yield.
a Reaction conditions: aryl halides (1.0 mmol), m-cresol (1.0 mmol), CuI (0.1 mmol), L1 (0.2 mmol), 2.0 equiv K2CO3, DMSO (3 mL), 120 °C.
b Isolated yield.