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. 2021 Apr 30:9:672051.
doi: 10.3389/fchem.2021.672051. eCollection 2021.

Metal-Free Direct C-H Functionalization of Quinoxalin-2(1 H)-Ones to Produce 3-Vinylated Quinoxalin-2(1 H)-Ones in the Presence of Alkenes

Rongcai Ding  1 , Yingxue Li  1 , Yaoyao Chang  1 , Yue Liu  1 , Jie Yu  1 , Yanna Lv  1 , Jinxing Hu  1
Affiliations

Metal-Free Direct C-H Functionalization of Quinoxalin-2(1 H)-Ones to Produce 3-Vinylated Quinoxalin-2(1 H)-Ones in the Presence of Alkenes

Rongcai Ding et al. Front Chem. .

Abstract

A novel and efficient C 3-H vinylation reaction with quinoxalin-2(1H)-one as the substrate, in the presence of alkenes, under metal-free conditions, is reported herein. The reaction leads to the formation of new carbon-carbon bonds that exhibit moderate to good reactivities. The vinylation of quinoxalin-2(1H)-ones, in the presence of alkenes, is an attractive process that can be potentially utilized to produce biologically active 3-vinylated quinoxalin-2(1H)-ones.

Keywords: C–H functionalization; alkenes; ammonium persulfate; cross-dehydrocoupling; vinylation.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Scheme 1
Scheme 1
Synthesis of C3 alkyl/vinyl substituted quinoxalin-2(1H)-ones.
Scheme 2
Scheme 2
Coupling Reaction of Quinoxalin-2(1H)-ones and Alkenes. Reaction conditions: 1a (0.25 mmol), 2a (0.75 mmol), Oxidant (1 mmol), base (0.75 mmol), and solvent at 80°C for 10 h under air.
Scheme 3
Scheme 3
Large scale experiment: 1a (7.0 mmol), 2a (21.0 mmol), (NH4)2S2O8(19.6 mmol), Cs2CO3 (10.3 mmol) in 20 mL of DMSO, 80°C, 24 h. Product 3a was isolated in 52% yield.
Scheme 4
Scheme 4
Controlled experiments.
Scheme 5
Scheme 5
Proposed mechanism.
See this image and copyright information in PMC

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