Base-catalyzed Formation of Enamines from β,β-Dicyanostyrene Derivatives with N-Bromosaccharin  

作　　者：KANG Nan CHEN Zhanguo 

机构地区：[1]Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory for Macromoleeular Science of Shaanxi Province,School of Chemistry and Chemical Engineering, Shaanxi Normal University,Xi 'an 710119, R. P China

出　　处：《Chemical Research in Chinese Universities》2018年第5期751-757,共7页高等学校化学研究（英文版）

基　　金：Supported by the Natural Science Foundation of Shaanxi Province of China（No. 20093M2011）, and the Innovation Founda- tion of Postgraduate Cultivation of Shaanxi Normal University of China（No. 2008CXB009）.

摘　　要：A new method for the synthesis of functional enamines from β,β-dicyanostyrene derivatives and N-bromosaccharin（NBSA） was developed. In the presence of Na2CO3, the the reaction of β,β-dicyanostyrene derivatives with NBSA can generate the corresponding enamines smoothly in a mixed solvent of dichloromethane and N,N-dimethylformamide（DMF）（volume ratio 1：1） at 50 ℃. The reaction of 14 kinds of β,β-dicyanostyrene derivatives with NBSA was investigated. Screened olefins afforded the corresponding enamines in good to excellent yields（up to 94%）, indicating that the method has a wide adaptability for the substrate. The catalyst used is inexpen- sive and stable for storage. The amino groups of all products in their structures are on the a-position of products, revealing the reaction has an excellent regioselectivity. The possible pathway involving aminobromination of β,βdicyanostyrene derivative with NBSA first and then elimination of HBr process in one pot has been proposed. The structures of all products were confirmed by ^1H NMR, ^13C NMR and HRMS analysis.A new method for the synthesis of functional enamines from β,β-dicyanostyrene derivatives and N-bromosaccharin（NBSA） was developed. In the presence of Na2CO3, the the reaction of β,β-dicyanostyrene derivatives with NBSA can generate the corresponding enamines smoothly in a mixed solvent of dichloromethane and N,N-dimethylformamide（DMF）（volume ratio 1：1） at 50 ℃. The reaction of 14 kinds of β,β-dicyanostyrene derivatives with NBSA was investigated. Screened olefins afforded the corresponding enamines in good to excellent yields（up to 94%）, indicating that the method has a wide adaptability for the substrate. The catalyst used is inexpen- sive and stable for storage. The amino groups of all products in their structures are on the a-position of products, revealing the reaction has an excellent regioselectivity. The possible pathway involving aminobromination of β,βdicyanostyrene derivative with NBSA first and then elimination of HBr process in one pot has been proposed. The structures of all products were confirmed by ^1H NMR, ^13C NMR and HRMS analysis.

关 键 词：β β-Dicyanostyrene derivative Functional enamine Sodium carbonate N-Bromosaccharin 

分 类 号：O636.1[理学—高分子化学] O643.36[理学—化学]