Triflic Acid‐Catalyzed Enynes Cyclization: A New Strategy beyond Electrophilic π‐Activation |
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Authors: | Zhunzhun Yu Prof?Dr Lu Liu Prof?Dr Junliang Zhang |
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Institution: | 1. Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, P. R. China;2. State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, P. R. China |
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Abstract: | The cyclization of enynes, catalyzed by a transition metal, represents a powerful tool to construct an array of cyclic compounds through electrophilic π‐activation. In this paper, we disclose a new and efficient strategy for enynes cyclization catalyzed by triflic acid. The salient features of this transformation includes a broad substrate scope, metal free synthesis, open flask and mild conditions, good yields, ease of operation, low catalyst loading, and easy scale‐up to gram scale. A preliminary mechanism study demonstrated that the activation model of the reaction was σ‐activation, which is different from the transition‐metal‐catalyzed enynes cyclization. Our strategy affords a complementary method to the traditional strategies, which use transition‐metal catalysts. |
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Keywords: | σ -activation enynes organic chemistry synthetic methods triflic acid |
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