文献类型：期刊文献

英文题名：Palladium catalyzed reductive homocoupling reactions of aromatic halides in dimethyl sulfoxide (DMSO) solution

作者：Qi, Chenze[1];Sun, Xudong[1];Lu, Cuiyun[1];Yang, Jinzhi[1];Du, Yijun[1];Wu, Huajiang[1];Zhang, Xian-Man[1]

机构：[1]Shaoxing Univ, Dept Chem, Shaoxing 312000, Zhejiang, Peoples R China

年份：2009

卷号：694

期号：18

起止页码：2912

外文期刊名：JOURNAL OF ORGANOMETALLIC CHEMISTRY

收录：SCI-EXPANDED(收录号：WOS:000268265200007)、、EI(收录号：20093012215783)、Scopus(收录号：2-s2.0-67650578125)、WOS

基金：This work was generously supported by the Natural Science Foundation of Zhejiang Province, People's Republic of China and Shaoxing University. We would like to thank Dr. Z. Fang for his kind help for the XPS measurements and helpful discussions.

语种：英文

外文关键词：Palladium catalyst; Homocoupling; Aromatic halides; Alkali fluoride bases; X-ray photoelectron spectroscopy; Reaction mechanism

外文摘要：Biaryls were obtained in good to excellent yields from the palladium catalyzed reductive homocoupling reactions of various aryl iodides and bromides in dimethyl sulfoxide (DMSO) solution without the need for any additional reducing reagents. Pd(dppf)Cl(2) is the most effective among the screened palladium catalysts for the homocoupling reactions. Fluorides, carbonates, acetates and hydroxides can be used as bases at promoting the palladium catalyzed reductive homocoupling of aryl halides in DMSO solution. X-ray photoelectron spectroscopic (XPS) analysis shows that the oxidative Pd(2+)(dppf) species can be reduced into the Pd(0)(dppf) active species by solvent DMSO molecules to furnish the catalytic cycle, indicating that DMSO plays a dual role as both solvent and reducing reagent. A plausible reaction mechanism has been discussed. Elimination of additional reducing reagents will not only reduce the reaction operation cost, but will also simplify the product separation and purification. (C) 2009 Elsevier B.V. All rights reserved.