The thermal cyclization of 3,4-diphenylbuta-1,3-dienyl isocyanates 1, generated in situ from the corresponding azides, was investigated using iodine as a catalyst. Diphenylpyridinones 2, phenylnaphthalenes 3, and indenes 4 were produced viaintramolecularringclosure. The nature of the substituents on the phenyl rings was found to be crucial to the distribution of cyclized products 2–4. The mechanism
Intramolecular Biaryl Oxidative Coupling of Stilbenes by Vanadium Oxytrichloride (VOCl<sub>3</sub>): Facile Synthesis of Substituted Phenanthrene Derivatives
作者:Zhong Jin、Qingmin Wang、Runqiu Huang
DOI:10.1081/scc-120027245
日期:2004.12.31
Abstract Vanadium oxytrichloride (VOCl3) has proven to be a highly efficient reagent for intramolecular biaryl oxidative coupling reaction of electron‐rich stilbenes. Accordingly, a mild and efficient route to phenanthrene derivatives from stilbenes oxygenated is developed.
Intramolecular Dehydrogenative Coupling of 2,3-Diaryl Acrylic Compounds: Access to Substituted Phenanthrenes
作者:Vijay Gupta、V. U. Bhaskara Rao、Tamal Das、Kumar Vanka、Ravi P. Singh
DOI:10.1021/acs.joc.6b00507
日期:2016.7.1
environmentally benign intramolecular dehydrogenative coupling of various 1,2-diarylethylenes for the synthesis of phenanthrenes in excellent yield has been described. This new methodology uses ceric ammonium nitrate (CAN) as a promoter at room temperature and has been extended to intermolecular synthesis of biaryl compounds. The electron transfer from methoxyarene to cerium leads to cationic radical formation
A Novel Sodium Nitrite-Catalyzed Oxidative Coupling for Constructing Polymethoxyphenanthrene Rings
作者:Bo Su、Ling Li、Yanna Hu、Yuxiu Liu、Qingmin Wang
DOI:10.1002/adsc.201100578
日期:2012.2
An efficient and green oxidativecoupling for the direct construction of polymethoxyphenanthrenerings has been developed, which uses environment-friendly sodium nitrite as catalyst and oxygen as terminal oxidant. This methodology also provides an alternative possibility for forming biaryl products.
Polymethoxy-substituted phenanthrene-9-carboxylic acids or their methylate are keyintermediates for the synthesis of tylophora alkaloids and their analogs. An intramolecular oxidative coupling reaction of unfunctionalized 2,3-disubstituted phenyl acrylic acids and derivatives promoted by di-tert-butylperoxide gave above intermediates in high yields. The mild reaction conditions and easy purification