The photochemical arylation of pyrimidines and pyrazines proceeds smoothly under moderate UVA irradiation and allows us to obtain high-value biaryl compounds through radical intermediates.
Pd(OAc)2/DABCO-catalyzed Suzuki–Miyaura cross-coupling reaction in DMF
作者:Jin-Heng Li、Qi-Ming Zhu、Ye-Xiang Xie
DOI:10.1016/j.tet.2006.08.103
日期:2006.11
The scope and limitations of the Pd(OAc)(2)/DABCO (1,4-diaza-bicyclo[2.2.2]octane)-catalyzed Suzuki-Miyaura cross-coupling reactions have been demonstrated. The results showed that the effect of solvent had a fundamental influence on the reaction. In the presence of Pd(OAc)2 and DABCO, both aryl bromides and aryl chlorides all worked well with arylboronic acids to form biaryls, heteroaryl-aryls, and bibeteroaryls in moderate to excellent yields using DMF as the solvent. Additionally, the reactions of aryl bromides were conducted under relatively mild conditions. (c) 2006 Elsevier Ltd. All rights reserved.
Solvent‐Free, Palladium‐Catalyzed Suzuki–Miyaura Cross‐Couplings of Aryl Chlorides with Arylboronic Acids
作者:Jin‐Heng Li、Chen‐Liang Deng、Ye‐Xiang Xie
DOI:10.1080/00397910701412828
日期:2007.7
Abstract Pd(MeCN)2Cl2/PCy3 was found to be an efficient catalytic system for the Suzuki–Miyauracross‐couplings of aryl chlorides with arylboronic acids undersolvent‐freeconditions. Furthermore, the presence of the conventional solvents had deleterious effect on the reaction. In the presence of Pd(MeCN)2Cl2, PCy3, and TBAF (tetra‐n‐butylammonium fluoride), a number of aryl chlorides including heteroaryl