Visible-light-mediated direct C3 alkylation of quinoxalin-2(1H)-ones using alkanes
Kai-Kai Niu1, Jing Cui1, Rui-Zhi Dong1
1School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255000, P. R. China. kkai007@126.com.
Abstract:
Due to the high C-H bond dissociation energy of alkanes, the utilization of alkanes as alkyl radical precursors for C-H functionalization of heteroarenes is synthetically captivating but practically challenging, especially under metal- and photocatalyst-free conditions. We report herein a mild and practical visible-light-mediated method for C-H alkylation of quinoxalin-2(1H)-ones using trifluoroacetic acid as a hydrogen atom transfer reagent and air as an oxidant. This mild protocol was performed under metal- and photocatalyst-free circumstances and presented good functional-group tolerance as well as a broad substrate scope.
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