CuCl<sub>2</sub>-Promoted 6-<i>endo-dig</i> Chlorocyclization and Oxidative Aromatization Cascade: Efficient Construction of 1-Azaanthraquinones from <i>N</i>-Propargylaminoquinones
作者:Na Fei、Hao Yin、Shaozhong Wang、Huaqin Wang、Zhu-Jun Yao
DOI:10.1021/ol201542h
日期:2011.8.19
An efficient synthetic methodology was developed to assemble 1-azaanthraquinones from N-propargylaminoquinones by copper(II)-promoted sequential 6-endo-dig chlorocyclization and oxidative aromatization. The approach can be extended to preprare chlorinated alkaloids such as cleistophine and sampangine. A possible mechanism involving carbon-carbon bond formation triggered by regioselective electrophilic activation and carbon-chlorine bond formation via reductive elimination was proposed.
Azaanthraquinone Assembly from <i>N</i>-Propargylamino Quinone via a Au(I)-Catalyzed 6-<i>endo</i>-<i>dig</i> Cycloisomerization
作者:Chunhui Jiang、Min Xu、Shaozhong Wang、Huaqin Wang、Zhu-Jun Yao
DOI:10.1021/jo1006637
日期:2010.6.18
the azaanthraquinone skeleton from N-propargylamino quinone by a Au(I)-catalyzed 6-endo-dig cycloisomerization was developed. The catalytic process was applied to the synthesis of alkaloidcleistopholine and its analogues. A mechanism involving benign nucleophilicity of the aminoquinone was proposed.
Azaanthraquinone assembly from N-propargylamino quinone via iodine-induced 6-endo-dig electrophilic cyclization
作者:Na Fei、Qiwen Hou、Shaozhong Wang、Huaqin Wang、Zhu-Jun Yao
DOI:10.1039/c004896h
日期:——
An efficient methodology taking advantage of the excellent nucleophilicity of aminoquinone to assemble the azaanthraquinone framework was developed via an iodine-induced 6-endo-dig electrophilic cyclization. Therefore, starting from N-propargylaminoquinones, various 3-iodo-1-azaanthraquinones were obtained in yields ranging from 45% to 90%. The metal-free protocol features facile installation of an iodine atom on the azaanthraquinone ring and benign functional group compatibility.