Electrochemical Umpolung of Bromide: Transition-Metal-Free Bromination of Indole C–H Bond
Abstract
:1. Introduction
2. Results and Discussions
3. Experimental Section
4. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Sample Availability: Samples of the compounds “3-bromoindole” are available from the authors. |
Entry | Bromide Source | Solvent | Constant Current | Yield (%) |
---|---|---|---|---|
1 | nBu4NBr/NH4Br (2 equiv.-2 equiv.) | 1,4-dioxane | 2 mA | <5 |
2 | nBu4NBr/NH4Br (2 equiv.-2 equiv.) | THF | 2 mA | 39 |
3 | nBu4NBr/NH4Br (2 equiv.-2 equiv.) | DCE | 2 mA | 43 |
4 | nBu4NBr/NH4Br (2 equiv.-2 equiv.) | DMF | 2 mA | 25 |
5 | nBu4NBr/NH4Br (2 equiv.-2 equiv.) | DMSO | 2 mA | 54 |
6 | nBu4NBr/NH4Br (2 equiv.-2 equiv.) | EtOAc | 2 mA | 58 |
7 | nBu4NBr/NH4Br (2 equiv.-2 equiv.) | EtOH | 2 mA | 20 |
8 | nBu4NBr/NH4Br (2 equiv.-2 equiv.) | MeCN | 2 mA | 81 |
9 | nBu4NBr/NaBr (2 equiv.-2 equiv.) | MeCN | 2 mA | 60 |
10 | nBu4NBr/KBr (2 equiv.-2 equiv.) | MeCN | 2 mA | 28 |
11 | nBu4NBr/NH4Br (2 equiv.-2 equiv.) | MeCN/H2O (10-2 mL) | 2 mA | 12 |
12 | nBu4NBr/NH4Br (1 equiv.-1 equiv.) | MeCN | 2 mA | 80 |
13 | nBu4NBr/NH4Br (1 equiv.-1 equiv.) | MeCN | 2 mA | 62 b |
14 | nBu4NBr/NH4Br/NaBr (1 -0.5-0.5 equiv.) | MeCN | 2 mA | 64 |
15 | nBu4NBr/NH4Br (4 equiv.-2 equiv.) | MeCN | 2 mA | 82 |
16 | NH4Br (2 equiv.) | MeCN | 2 mA | <5 |
17 | nBu4NBr (2 equiv.) | MeCN | 2 mA | 15 |
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Zhang, P.; Chen, J.; Gao, W.; Xiao, Y.; Liu, C.; Xu, S.; Yan, X.; Qin, D. Electrochemical Umpolung of Bromide: Transition-Metal-Free Bromination of Indole C–H Bond. Molecules 2019, 24, 696. https://doi.org/10.3390/molecules24040696
Zhang P, Chen J, Gao W, Xiao Y, Liu C, Xu S, Yan X, Qin D. Electrochemical Umpolung of Bromide: Transition-Metal-Free Bromination of Indole C–H Bond. Molecules. 2019; 24(4):696. https://doi.org/10.3390/molecules24040696
Chicago/Turabian StyleZhang, Pan, Jianbin Chen, Wei Gao, Yiting Xiao, Changwei Liu, Shanghui Xu, Xiaoli Yan, and Dawei Qin. 2019. "Electrochemical Umpolung of Bromide: Transition-Metal-Free Bromination of Indole C–H Bond" Molecules 24, no. 4: 696. https://doi.org/10.3390/molecules24040696