C-N Coupling of Azoles or Imides with Carbocations Generated by Electrochemical Oxidation
作者:Xiaoqing Shao、Lifang Tian、Yahui Wang
DOI:10.1002/ejoc.201900714
日期:2019.7.7
1,3,5‐Cycloheptatriene and xanthenes undergo anodic oxidation to generate the tropylium ion and xanthene cations. These can be subsequently trapped by nucleophilic attack of azoles and imides to form C–N bonds.
Only oxygen and acid! The oxidative coupling of xanthene and other activated benzylic compounds with carbon nucleophiles such as ketones, can be performed under ambient conditions without solvent by simply using oxygen and catalytic amounts of methanesulfonic acid. The proposed reaction mechanism involves substrate activation by formation of hydroperoxides; the method can therefore be regarded as an
By employing a readily available CuCl/DDQ catalyst system, we herein report a directC(sp3)–Hsulfonylation of xanthene derivates with odorless sodium sulfinates. Various 9H-xanthenes, thioxanthenes, and 9,10-dihydroacridines are efficiently transformed into the desired benzylic sulfonyl products via a radical/radical cross-coupling process, proceeding with the merits of broad substrate scope, operational
Electrochemically Mediated S-Glycosylation of 1-Thiosugars with Xanthene Derivatives
作者:Rui-Qi Wang、Qing-Hui Jiang、Hui-Xiang Wang、Xiao-Wei Zhang、Nan Yan
DOI:10.1021/acs.orglett.3c01185
日期:2023.6.16
electrochemical dehydrogenativecross-coupling of benzylic C–H bonds with 1-thiosugars at room temperature is described. The direct S-glycosylation protocol avoids using any oxidant, which provides facile access to various glycosylated xanthene derivatives with up to 91% yield. This current electrooxidative reaction is characterized by high atom economy, high efficiency, mild reaction conditions, being