- Copper-catalyzed intramolecular cross dehydrogenative coupling approach to coumestans from 2′-hydroxyl-3-arylcoumarins
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A copper-catalyzed intramolecular cross dehydrogenative C-O coupling reaction of 2′-hydroxyl-3-arylcoumarins was developed. This protocol provided a facile and efficient strategy for the construction of natural coumestans and derivatives in moderate to high yields. This transformation exhibited good functional group compatibility and was amenable to substrates with free phenolic hydroxyl groups.
- Song, Xianheng,Luo, Xiang,Sheng, Jianfei,Li, Jianheng,Zhu, Zefeng,Du, Zhibo,Miao, Hui,Yan, Meng,Li, Mingkang,Zou, Yong
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p. 17391 - 17398
(2019/06/24)
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- Tin tetrachloride-catalyzed regiospecific allylic substitution of quinone monoketals: An easy entry to benzofurans and coumestans
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A highly regioselective allylic substitution of quinone monoketals with a-oxoketene dithioacetals is achieved under the catalysis of only tin tetrachloride (1 mol%). The advantages of the reaction, including its simplicity, rapidity, low catalyst loading of inexpensive tin tetrachloride, mild conditions and; in particular, the regiospecificity, is proposed to be due to a pseudo-intramolecular process. This new synthetic method provides a facile [3+2] cycloaddition route to benzofurans and is highlighted by the synthesis of coumestans.
- Liu, Yingjie,Liu, Jingxin,Wang, Mang,Liu, Jun,Liu, Qun
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p. 2678 - 2682
(2013/01/15)
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- Synthesis of coumestan derivatives via FeCl3-mediated oxidative ring closure of 4-hydroxy coumarins
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A concise and efficient approach to the syntheses of coumestan analogues has been developed. The underpinning strategy involves a FeCl 3-mediated direct intramolecular oxidative annellation of 4-hydroxy-3-phenyl-2H-chromen-2-one derivatives. Utilizing this synthetic protocol, a variety of coumestan derivatives were conveniently obtained from readily available reagents.
- Tang, Lina,Pang, Yongle,Yan, Qiao,Shi, Liuqing,Huang, Jianhui,Du, Yunfei,Zhao, Kang
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experimental part
p. 2744 - 2752
(2011/06/17)
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