- Synthesis of quinoxalines through iodine-catalyzed one-pot annulation of alkynes with o-phenylenediamines
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The synthesis of N-heterocycles of quinoxalines has been developed by an efficient protocol of one-pot annulation of alkynes with o-phenylenediamines. A variety of quinoxalines were prepared in good to high yields in the presence of catalytic amount of iodine as a catalyst.
- Zi, Jing,Gu, Da-Wei,Zhang, Yan,Hu, Zhe-Yao,Zhang, Xing-Quan,Guo, Xun-Xiang
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- Copper-catalyzed base-accelerated direct oxidation of C-H bond to synthesize benzils, isatins, and quinoxalines with molecular oxygen as terminal oxidant
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We describe herein an efficient and general copper (II)-catalyzed base-accelerated oxidation of the C-H bond to synthesize benzils and isatins. With similar oxidation system an efficient one-pot procedure for the synthesis of quinoxaline derivatives was realized. The two protocols feature using molecular oxygen as terminal oxidant, low catalyst loading, wide substrate scope, and high functional-group tolerance.
- Yu, Jing-Wen,Mao, Shuai,Wang, Yong-Qiang
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p. 1575 - 1580
(2015/03/14)
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- Elemental iodine or diphenyl diselenide in the [bis(trifluoroacetoxy)iodo] benzene-mediated conversion of alkynes into 1,2-diketones
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Both elemental iodine and diphenyl diselenides, in the presence of [bis(trifluoroacetoxy)iodo]benzene (PIFA), promote the transformation of internal alkynes into the corresponding 1,2-diketones. The reactions carried out in the presence of iodine unfortunately did not proceed with complete conversion of the starting alkynes. On the other hand, diphenyl diselenide was more efficient and gave satisfactory transformation of the starting alkynes into 1,2-diketones in better yields. The structure of the vicinal dicarbonyl compounds were confirmed by applying a subsequent condensation reaction to construct the corresponding quinoxaline derivatives. Both elemental iodine and diphenyl diselenide in the presence of [bis(trifluoroacetoxy)iodo]benzene (PIFA) promote the transformation of internal alkynes into 1,2-diketones. The structure of the products were confirmed by transformation into the corresponding quinoxaline derivatives, two of which were studied by X-ray analysis. Copyright
- Tingoli, Marco,Mazzella, Mauro,Panunzi, Barbara,Tuzi, Angela
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experimental part
p. 399 - 404
(2011/02/28)
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