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Selective Mono- and Diamination of Ketones in a Combined Copper-Organocatalyst System
Jiabin Shen1, Zhihao Wang1, Yuru Zhang1
1College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou, Zhejiang 311121, People's Republic of China.
Abstract:
Herein, we report a simple and mild protocol for the chemoselective mono- and diamination of ketone using pyrazole as the amine source in a combined copper-organocatalyst system. Various substrates are compatible, providing the corresponding products in moderate to good yields. This strategy gives an efficient and convenient solution for the synthesis of α-pyrazole and α,α-dipyrazole ketone derivatives. The control experiment demonstrates that in situ generated hydrazone is a key intermediate in the transformation.
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