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Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Efficient Synthesis of 1,4-Diazepines via Tf2O Promoted [5+2] Annulation of Ynamides with Imidazolidines
Baoxin Zhang1, Chao Pi1, Yangjie Wu1
1Henan Key Laboratory of Chemical Biology and Organic Chemistry, Key Laboratory of Applied Chemistry of Henan Universities, Pingyuan Laboratory, State Key Laboratory of Coking Coal Resources Green Exploitation and College of Chemistry, Zhengzhou University, Zhengzhou, 450052, P. R. China.
Abstract:
A Tf2O-promoted [5+2] annulation of imidazolidines with ynamides has been developed, providing an efficient and sustainable strategy for the synthesis of 1,4-diazepines under the mild and metal-free conditions. A diverse of 6-aryl/alkyl substituted 5-amino-1,4-diazepines were formed in moderate to excellent yields. This transformation features with broad substrate scope, operational simplicity, environmental compatibility, and atomic economy. This protocol provides a sustainable alternative pathway for the synthesis of N-heterocycles.
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