Gold-Catalyzed Domino Synthesis of Functionalized Benzofurans and Tetracyclic Isochromans via Formal Carboalkoxylation

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• 作者：Tomoyuki Obata ; Sho Suzuki ; Asuka Nakagawa ; Ryota Kajihara ; Keiichi Noguchi ; Akio Saito
• 刊名：Organic Letters
• 出版年：2016
• 出版时间：August 19, 2016
• 年：2016
• 卷：18
• 期：16
• 页码：4136-4139
• 全文大小：401K
• 年卷期：0
• ISSN：1523-7052

文摘

A domino synthesis of benzofurans with the modification of side chains from α-alkoxyalkyl o-alkynylaryl ethers (n = 0) and electron-rich arenes has been developed. In the present domino reaction, which would proceed via the α-alkoxyalkylation of arenes with an intermediate in the migratory cycloisomerization of o-alkynylaryl ethers followed by the nucleophilic addition of benzofurans to benzyl ethers, a cationic Au(III) catalyst activates the C–C π bond and the C–O σ bond. The present method could be extended to Au(I)-catalyzed domino synthesis of tetracyclic isochromans from α-alkoxyalkyl (o-alkynylaryl)methyl ethers (n = 1) and aryl methoxymethyl ethers.