Advanced Synthesis & Catalysis

Domino Sonogashira coupling/cyclization reaction catalyzed by copper and ppb levels of palladium: a concise route to indoles and benzo [b] furans

R Wang, S Mo, Y Lu, Z Shen

Index: Wang, Ruiping; Mo, Song; Lu, Yongzhong; Shen, Zengming Advanced Synthesis and Catalysis, 2011 , vol. 353, # 5 p. 713 - 718

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Citation Number: 46

Abstract

Abstract Both indoles and benzo [b] furans can be obtained in high yield by the reactions of 2-iodoaniline derivatives and 2-iodophenols with terminal alkynes under mild conditions, namely in the presence of cuprous iodide (10 mol%) and a base in ethanol or 1, 4-dioxane. Further investigation reveals that palladium contaminants as low as 100 ppb are responsible for these successful couplings. It is worth noting that simple aliphatic substituted terminal ...