An economical and environmentally friendly oxidative biaryl coupling promoted by activated MnO<sub>2</sub>
作者:Jingjing Yang、Shutao Sun、Ziyu Zeng、Hongbo Zheng、Wei Li、Hongxiang Lou、Lei Liu
DOI:10.1039/c4ob01409j
日期:——
An activated manganese dioxide (MnO2)–BF3·OEt2 oxidation system was developed to efficiently mediate the intramolecular as well as intermolecular biaryl coupling. The oxidative coupling proceeds smoothly at ambient temperature to deliver the corresponding five- to eight-membered tricyclic products in good to excellent yields. The employment of the combination of MnO2 and BF3·OEt2 is attractive on the basis of economical and environmental issues.
Oxidative Biaryl Coupling Reaction of Phenol Ether Derivatives Using a Hypervalent Iodine(III) Reagent
作者:Takeshi Takada、Mitsuhiro Arisawa、Michiyo Gyoten、Ryuji Hamada、Hirofumi Tohma、Yasuyuki Kita
DOI:10.1021/jo980704f
日期:1998.10.1
The hypervalent iodine(III)-induced intramolecular biaryl coupling reaction of phenol ether derivatives (nonphenolic derivatives) was investigated with the aim of preparing various dibenzo heterocyclic compounds. 1,3-Diarylpropanes (1a-e), N-benzyl-N-phenethylamines (2a-c) and N,N-dibenzylamines (3a-e) react with a hypervalent iodine reagent, phenyliodine(III) bis(trifluoroacetate) (PIFA), containing BF3. Et2O in CH2Cl2 to give the biaryl coupling products (4-6) in good yield. As an application of the reaction, we examined the synthesis of oxygen- and sulfur-containing dibenzoheterocyclic compounds (12-15), whose side chain moiety could be easily cleaved by the known method to give 2,2'-substituted biphenyl compounds (16-18).
Seven- and eight-membered heterocyclic biaryl synthesis through a metal-free oxidative coupling reaction
作者:Shutao Sun、Jingjing Yang、Fanmei Li、Zheng Lv、Wei Li、Hongxiang Lou、Lei Liu
DOI:10.1016/j.tetlet.2014.10.103
日期:2014.12
A metal-free intramolecular biaryl coupling mediated by DDQ and BF3 center dot OEt2 was developed. The reaction proceeds smoothly at room temperature to give seven- and eight-membered heterocyclic biaryl compounds in up to 95% yields. Only 1 equiv of DDQ sufficed for the reaction, obviating the use of a large excess of oxidants and undesired chlorination pathway in metal-mediated process. (C) 2014 Elsevier Ltd. All rights reserved.
<i>p</i>-Hydroxy-Benzyl Ethers As Lignin Models. II