Synthesis of highly substituted indolines and indoles via intramolecular [4+ 2] cycloaddition of ynamides and conjugated enynes

JR Dunetz, RL Danheiser

Index: Dunetz, Joshua R.; Danheiser, Rick L. Journal of the American Chemical Society, 2005 , vol. 127, # 16 p. 5776 - 5777

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Citation Number: 131

Abstract

Ynamides react with conjugated enynes in intramolecular [4+ 2] cycloadditions to afford substituted indolines that undergo oxidation with o-chloranil to furnish the corresponding indoles. The cycloaddition substrates are easily assembled from derivatives of 3- butynylamine by Sonogashira coupling with alkenyl halides followed by copper-catalyzed N- alkynylation with acetylenic bromides. Diynamides participate as particularly reactive 2π ...