Phosphine-Catalyzed (4 + 1) Annulation of o-Hydroxyphenyl and o-Aminophenyl Ketones with Allylic Carbonates: Syntheses and Transformations of 3-Hydroxy-2,3-Disubstituted Dihydrobenzofurans and Indolines

详细信息    查看全文

• 作者：Zifeng Qin ; Wei Liu ; Danyang Wang ; Zhengjie He
• 刊名：Journal of Organic Chemistry
• 出版年：2016
• 出版时间：June 3, 2016
• 年：2016
• 卷：81
• 期：11
• 页码：4690-4700
• 全文大小：472K
• 年卷期：0
• ISSN：1520-6904

文摘

A phosphine-catalyzed (4 + 1) annulation reaction of o-hydroxyphenyl and o-aminophenyl ketones with ester-modified allylic carbonates has been developed, providing a facile and efficient method to synthesize functionalized 2,3-disubstituted dihydrobenzofurans and indolines. Under mild conditions and in the catalysis of PPh₃ (20 mol %), the reactions of o-hydroxyphenyl or o-aminophenyl ketones readily furnish highly functionalized 3-hydroxy-2,3-disubstituted dihydrobenzofurans or 3-hydroxy-2,3-disubstituted indolines in 40–99% yields with generally high diastereoselectivity. To further expand the utility of this annulation reaction to the synthesis of functionalized benzofurans and indoles, the CuSO₄-promoted chemical transformations of the annulation products have also been studied.