Green oxidation of indoles using halide catalysis
Oxidation of indoles is a fundamental organic transformation to deliver a variety of synthetically and pharmaceutically valuable nitrogen-containing compounds. Prior methods require the use of either organic oxidants (meta-chloroperoxybenzoic acid, N-bromosuccinimide, t-BuOCl) or stoichiometric toxi...
| Main Authors: | , , , , |
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| Format: | Journal Article |
| Language: | English |
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2022
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| Online Access: | https://hdl.handle.net/10356/155119 |
| _version_ | 1811678214415712256 |
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| author | Xu, Jun Liang, Lixin Zheng, Haohao Chi, Robin Yonggui Tong, Rongbiao |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Xu, Jun Liang, Lixin Zheng, Haohao Chi, Robin Yonggui Tong, Rongbiao |
| author_sort | Xu, Jun |
| collection | NTU |
| description | Oxidation of indoles is a fundamental organic transformation to deliver a variety of synthetically and pharmaceutically valuable nitrogen-containing compounds. Prior methods require the use of either organic oxidants (meta-chloroperoxybenzoic acid, N-bromosuccinimide, t-BuOCl) or stoichiometric toxic transition metals [Pb(OAc)4, OsO4, CrO3], which produced oxidant-derived by-products that are harmful to human health, pollute the environment and entail immediate purification. A general catalysis protocol using safer oxidants (H2O2, oxone, O2) is highly desirable. Herein, we report a unified, efficient halide catalysis for three oxidation reactions of indoles using oxone as the terminal oxidant, namely oxidative rearrangement of tetrahydro-β-carbolines, indole oxidation to 2-oxindoles, and Witkop oxidation. This halide catalysis protocol represents a general, green oxidation method and is expected to be used widely due to several advantageous aspects including waste prevention, less hazardous chemical synthesis, and sustainable halide catalysis. |
| first_indexed | 2024-10-01T02:49:42Z |
| format | Journal Article |
| id | ntu-10356/155119 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T02:49:42Z |
| publishDate | 2022 |
| record_format | dspace |
| spelling | ntu-10356/1551192023-02-28T19:56:15Z Green oxidation of indoles using halide catalysis Xu, Jun Liang, Lixin Zheng, Haohao Chi, Robin Yonggui Tong, Rongbiao School of Physical and Mathematical Sciences Science::Chemistry Homogeneous Catalysis Synthetic Chemistry Methodology Oxidation of indoles is a fundamental organic transformation to deliver a variety of synthetically and pharmaceutically valuable nitrogen-containing compounds. Prior methods require the use of either organic oxidants (meta-chloroperoxybenzoic acid, N-bromosuccinimide, t-BuOCl) or stoichiometric toxic transition metals [Pb(OAc)4, OsO4, CrO3], which produced oxidant-derived by-products that are harmful to human health, pollute the environment and entail immediate purification. A general catalysis protocol using safer oxidants (H2O2, oxone, O2) is highly desirable. Herein, we report a unified, efficient halide catalysis for three oxidation reactions of indoles using oxone as the terminal oxidant, namely oxidative rearrangement of tetrahydro-β-carbolines, indole oxidation to 2-oxindoles, and Witkop oxidation. This halide catalysis protocol represents a general, green oxidation method and is expected to be used widely due to several advantageous aspects including waste prevention, less hazardous chemical synthesis, and sustainable halide catalysis. Published version This research was financially supported by Research Grant Council of Hong Kong (16311716, 16303617, 16304618) and National Natural Science Foundation of China (21772167). Dr. J.X. also acknowledged the Doctor Start-up Fund ([2018]28) and the Guizhou Province First-Class Disciplines Project (Yiliu Xueke Jianshe Xiangmu-GNYL [2017]008) from Guizhou University of Traditional Chinese Medicine (China). 2022-02-09T06:36:38Z 2022-02-09T06:36:38Z 2019 Journal Article Xu, J., Liang, L., Zheng, H., Chi, R. Y. & Tong, R. (2019). Green oxidation of indoles using halide catalysis. Nature Communications, 10(1), 4754-. https://dx.doi.org/10.1038/s41467-019-12768-4 2041-1723 https://hdl.handle.net/10356/155119 10.1038/s41467-019-12768-4 31628334 2-s2.0-85073603842 1 10 4754 en Nature Communications © 2019 The Author(s). This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/ licenses/by/4.0/. application/pdf |
| spellingShingle | Science::Chemistry Homogeneous Catalysis Synthetic Chemistry Methodology Xu, Jun Liang, Lixin Zheng, Haohao Chi, Robin Yonggui Tong, Rongbiao Green oxidation of indoles using halide catalysis |
| title | Green oxidation of indoles using halide catalysis |
| title_full | Green oxidation of indoles using halide catalysis |
| title_fullStr | Green oxidation of indoles using halide catalysis |
| title_full_unstemmed | Green oxidation of indoles using halide catalysis |
| title_short | Green oxidation of indoles using halide catalysis |
| title_sort | green oxidation of indoles using halide catalysis |
| topic | Science::Chemistry Homogeneous Catalysis Synthetic Chemistry Methodology |
| url | https://hdl.handle.net/10356/155119 |
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