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I2-Catalyzed Cycloisomerization of Ynamides: Chemoselective and Divergent Access to Indole Derivatives |
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| Authors: | Bo-Han Zhu Sheng-Bing Ye Min-Ling Nie Zhong-Yang Xie Yi-Bo Wang Prof Dr Peng-Cheng Qian Prof Dr Qing Sun Prof Dr Long-Wu Ye Prof Dr Long Li |
| Institution: | 1. College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou, 325035 China
Wenzhou Key Laboratory of Technology and Application of Environmental Functional Materials, Institute of New Materials & Industry Technology, Wenzhou University, Wenzhou, 325000 China These authors contributed equally to this work.;2. College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou, 325035 China Wenzhou Key Laboratory of Technology and Application of Environmental Functional Materials, Institute of New Materials & Industry Technology, Wenzhou University, Wenzhou, 325000 China;3. College of Chemistry & Materials Engineering, Wenzhou University, Wenzhou, 325035 China;4. Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063 China;5. State Key Laboratory of Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005 China |
| Abstract: | Herein, an I2-catalyzed unprecedented cycloisomerization of ynamides is developed, furnishing various functionalized bis(indole) derivatives in generally good to excellent yields with wide substrate scope and excellent atom-economy. This protocol not only represents the first molecular-iodine-catalyzed tandem complex alkyne cycloisomerizations, but also constitutes the first chemoselective cycloisomerization of tryptamine-ynamides involving distinctively different C(sp3)−C(sp3) bond cleavage and rearrangement. Moreover, chiral tetrahydropyridine frameworks containing two stereocenters are obtained with moderate to excellent diastereoselectivities and excellent enantioselectivities. Meanwhile, cycloisomerization and aromatization of ynamides produce pyrrolyl indoles with high efficiency enabled by I2. Additionally, control experiments and theoretical calculations reveal that this reaction probably undergoes a tandem 5-exo-dig cyclization/rearrangement process. |
| Keywords: | Alkynes Cycloisomerization Heterocycles Iodine Rearrangement |