N,N-Dimethyl Glycine-Promoted Ullmann Coupling Reaction of Phenols and Aryl Halides
Dawei Ma* and Qian Cai
*State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai
Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu,
Shanghai 200032, China, Email: madw
pub.sioc.ac.cn
D. Ma, Q. Cai, Org. Lett., 2003, 5, 3799-3802.
DOI: 10.1021/ol0350947
Abstract
Copper-catalyzed Ullmann-type diaryl ether synthesis can be performed at 90°C using either aryl iodides or aryl bromides as the substrates under the assistance of N,N-dimethylglycine.
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Details
The document discusses a study by Dawei Ma and Qian Cai on the Ullmann coupling reaction of phenols and aryl halides, facilitated by N,N-dimethylglycine. Traditionally, this reaction required high temperatures (125-220 °C) and stoichiometric amounts of copper catalysts, resulting in low to moderate yields. The authors developed a method to perform the reaction at a significantly lower temperature of 90 °C using aryl iodides or bromides as substrates. They found that N,N-dimethylglycine hydrochloride salt, when used with various copper salts, provided good to excellent yields of diaryl ethers. The study demonstrated that both electron-rich and electron-deficient aryl iodides and bromides could be effectively coupled with phenols under these conditions. The method showed tolerance for various functional groups and provided a more efficient and milder alternative to traditional Ullmann coupling reactions. The research was supported by the Chinese Academy of Sciences and other foundations, and further studies on more complex diaryl ethers and the reaction mechanism are ongoing.
N,N-Dimethylglycine-Promoted Ullmann-Type Coupling Reactions of Aryl Iodides with Aliphatic Alcohols
H. Zhang, D. Ma, W. Cao, Synlett, 2007, 243-246.
Key Words
Ullmann Coupling, Diaryl Ethers
ID: J54-Y2003-1010
