Stereoselective synthesis of 9-vinyl substituted unsymmetrical xanthenes and thioxanthenes
作者:Anamika Prajapati、Mahendra Kumar、Ranjit Thakuria、Ashok K. Basak
DOI:10.1016/j.tetlet.2020.152347
日期:2020.9
and 2-(arythio)benzaldehydes undergo intramolecular Friedel-Crafts alkylation reaction when heated with catalytic amount of a Lewis acid in 1,2-dichloroethane to provide highly E-selective 9-vinyl substituted unsymmetrical novel xanthenes and thioxanthenes in good yields.
Abstract A simple, general, and highly efficient Betti base ligand has been developed for copper-catalyzed Ullmann coupling of phenol with arylhalides without the protection of an inert atmosphere. The reaction proceeds smoothly in the presence of K2CO3 as the base and dimethylsulfoxide as the solvent. The catalyst was reused several times with no evident loss of catalytic activity and is environmentally
Highly Efficient Copper-Catalyzed O-Arylation Using Readily Available (<i>S</i>)-<i>N</i>-Methylpyrrolidine-2-Carboxamide as the Ligand
作者:Hua Fu、Xianghao Liu、Yuyang Jiang、Yufen Zhao
DOI:10.1055/s-2007-1000878
日期:2008.1
A highly efficient and readily available catalyst system for O-arylation of various phenols using CuI and (S)-N-methylpyrrolidine-2-carboxamide (Pro-NHMe) was developed. The reaction is widely applicable to the synthesis of diaryl ethers
An organocatalytic method for the synthesis of some novel xanthene derivatives by the intramolecular Friedel–Crafts reaction
作者:Tülay Yıldız、Hatice Başpinar Küçük
DOI:10.1039/c6ra27094h
日期:——
An efficient organocatalytic method for the synthesis of new substituted 9-arylxanthenes (2a–2u) starting from diarylcarbinol compounds with an arenoxy group (1a–1u) has been developed using the intramolecular Friedel–Crafts reaction. The substrates were prepared in two steps by Ullmann-type coupling and then Grignard reaction. Some organic Brønsted acids were studied as catalysts (3a–3g) in the intramolecular
tert-Butoxide mediated cascade desulfonylation/arylation/hydrolysis of cyclic sulfonyimines using diaryliodonium salts: synthesis of diaryl ether derivatives bearing a 2-aldehyde group
作者:Xiaofei Qian、Jianwei Han、Limin Wang
DOI:10.1039/c6ra19313g
日期:——
Cascades of cyclic sulfonyimines mediated by tBuOK with diaryliodonium salts has been developed, giving the diaryl ethers in good yields. Furthermore, bulky ortho-substituted diaryl ethers with an aldehyde group can be obtained easily in comparision with metal-catalyzed protocols.