New role of CO2 as a selective agent in palladium-catalyzed reductive Ullmann coupling with zinc in water.
Carbon dioxide was found to promote the palladium-catalyzed zinc-mediated reductive Ullmann coupling of aryl halides. In the presence of carbon dioxide, Pd/C, and zinc, various aromatic halides including less reactive aromatic chlorides were coupled to give the corresponding homocoupling products in good yields.
Li
Jin-Heng
JH
Institute of Fine Catalysis and Synthesis, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China. jhli@mail.hunnu.edu.cn
Xie
Ye-Xiang
YX
Yin
Du-Lin
DL