DDQ-mediated Direct Intramolecular-Dehydrogenative-Coupling (IDC): Expeditious Approach to the Tetracyclic Core of Ergot Alkaloids

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• 作者：Subhajit Bhunia ; Santanu Ghosh ; Dhananjay Dey ; Alakesh Bisai
• 刊名：Organic Letters
• 出版年：2013
• 出版时间：May 17, 2013
• 年：2013
• 卷：15
• 期：10
• 页码：2426-2429
• 全文大小：321K
• 年卷期：v.15,no.10(May 17, 2013)
• ISSN：1523-7052

文摘

An efficient route to 2-oxindoles bearing an all-carbon quaternary center at the pseudobenzylic position has been developed via a DDQ-mediated Intramolecular-Dehydrogenative-Coupling (IDC). The methodology involves a one-pot C-alkylation of 尾-N-arylamido esters (7) concomitant with dehydrogenative-coupling in the presence of stoichiometric amount of DDQ. A tentative mechanistic route has been proposed for the oxidative coupling. The methodology provides a two-step entry to the ergoline structure of ergot alkaloids.