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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
[4 + 2] Cyclization of para-Quinone Methide Derivatives with Alkynes
Guang-Jian Mei1, Shao-Li Xu1, Wen-Qin Zheng1
1School of Chemistry and Materials Science, Jiangsu Normal University , Xuzhou 221116, China.
Abstract:
The first cyclization of para-quinone methide derivatives with alkynes was established by utilizing the [4 + 2] reaction of ortho-hydroxyphenyl-substituted para-quinone methides with ynones or benzyne, which efficiently constructed the scaffolds of chromene and xanthene in high yields (up to 88%). This protocol has not only fulfilled the task of developing cyclization reactions of para-quinone methide derivatives but also provided an efficient method for constructing chromene and xanthene scaffolds.
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