β-Carboline Amides as Intrinsic Directing Groups for C(sp2)–H Functionalization

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• 作者：Hélène M.-F. Viart ; Andreas Bachmann ; William Kayitare ; Richmond Sarpong
• 刊名：Journal of the American Chemical Society
• 出版年：2017
• 出版时间：January 25, 2017
• 年：2017
• 卷：139
• 期：3
• 页码：1325-1329
• 全文大小：501K
• ISSN：1520-5126

文摘

Many site-selective palladium-catalyzed C–H functionalization methods require directing groups. We report here β-carboline amides as intrinsic directing groups for C(sp²)–H functionalization. Various substrates including the natural product alangiobussinine and the marinacarboline core structure were functionalized using carboline-directed δ-C(sp²)–H alkynylations. This transformation proceeds under mild conditions and is compatible with a wide variety of β-arylethamines. δ-Alkynylation of β-arylethamines via a six-membered palladacycle is favored over γ-C(sp²)–H bond functionalization when both positions are accessible. The versatility of β-carboline amides as directing groups is evidenced by other δ-C(sp²)–H functionalizations such as alkenylation, arylation, and C–N bond formation.