(Guanidine) copper complex-catalyzed enantioselective dynamic kinetic allylic alkynylation under biphasic condition
Highly enantioselective allylic alkynylation of racemic bromides under biphasic condition is furnished in this report. This approach employs functionalized terminal alkynes as pro-nucleophiles and provides 6- and 7-membered cyclic 1,4-enynes with high yields and excellent enantioselectivities (up to...
| Main Authors: | , , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2020
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| Online Access: | https://hdl.handle.net/10356/137033 |
| _version_ | 1826110083053912064 |
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| author | Cui, Xi-Yang Ge, Yicen Tan, Siu Min Jiang, Huan Tan, Davin Lu, Yunpeng Lee, Richmond Tan, Choon-Hong |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Cui, Xi-Yang Ge, Yicen Tan, Siu Min Jiang, Huan Tan, Davin Lu, Yunpeng Lee, Richmond Tan, Choon-Hong |
| author_sort | Cui, Xi-Yang |
| collection | NTU |
| description | Highly enantioselective allylic alkynylation of racemic bromides under biphasic condition is furnished in this report. This approach employs functionalized terminal alkynes as pro-nucleophiles and provides 6- and 7-membered cyclic 1,4-enynes with high yields and excellent enantioselectivities (up to 96% ee) under mild conditions. Enantioretentive derivatizations highlight the synthetic utility of this transformation. Cold-spray ionization mass spectrometry (CSI-MS) and X-ray crystallography were used to identify some catalytic intermediates, which include guanidinium cuprate ion pairs and a copper-alkynide complex. A linear correlation between the enantiopurity of the catalyst and reaction product indicates the presence of a copper complex bearing a single guanidine ligand at the enantio-determining step. Further experimental and computational studies supported that the alkynylation of allylic bromide underwent an anti-SN2' pathway catalyzed by nucleophilic cuprate species. Moreover, metal-assisted racemization of allylic bromide allowed the reaction to proceed in a dynamic kinetic fashion to afford the major enantiomer in high yield. |
| first_indexed | 2024-10-01T02:28:40Z |
| format | Journal Article |
| id | ntu-10356/137033 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T02:28:40Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | ntu-10356/1370332020-09-04T10:21:28Z (Guanidine) copper complex-catalyzed enantioselective dynamic kinetic allylic alkynylation under biphasic condition Cui, Xi-Yang Ge, Yicen Tan, Siu Min Jiang, Huan Tan, Davin Lu, Yunpeng Lee, Richmond Tan, Choon-Hong School of Physical and Mathematical Sciences Science::Chemistry Guanidine Anions Highly enantioselective allylic alkynylation of racemic bromides under biphasic condition is furnished in this report. This approach employs functionalized terminal alkynes as pro-nucleophiles and provides 6- and 7-membered cyclic 1,4-enynes with high yields and excellent enantioselectivities (up to 96% ee) under mild conditions. Enantioretentive derivatizations highlight the synthetic utility of this transformation. Cold-spray ionization mass spectrometry (CSI-MS) and X-ray crystallography were used to identify some catalytic intermediates, which include guanidinium cuprate ion pairs and a copper-alkynide complex. A linear correlation between the enantiopurity of the catalyst and reaction product indicates the presence of a copper complex bearing a single guanidine ligand at the enantio-determining step. Further experimental and computational studies supported that the alkynylation of allylic bromide underwent an anti-SN2' pathway catalyzed by nucleophilic cuprate species. Moreover, metal-assisted racemization of allylic bromide allowed the reaction to proceed in a dynamic kinetic fashion to afford the major enantiomer in high yield. Accepted version 2020-02-13T06:11:54Z 2020-02-13T06:11:54Z 2018 Journal Article Cui, X.-Y., Ge, Y., Tan, S. M., Jiang, H., Tan, D., Lu, Y., . . . Tan, C.-H. (2018). (Guanidine) copper complex-catalyzed enantioselective dynamic kinetic allylic alkynylation under biphasic condition. Journal of The American Chemical Society, 140(27), 8448-8455. doi:10.1021/jacs.7b12806 0002-7863 https://hdl.handle.net/10356/137033 10.1021/jacs.7b12806 29894179 2-s2.0-85048700509 27 140 8448 8455 en Journal of the American Chemical Society This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of the American Chemical Society, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/jacs.7b12806 application/pdf |
| spellingShingle | Science::Chemistry Guanidine Anions Cui, Xi-Yang Ge, Yicen Tan, Siu Min Jiang, Huan Tan, Davin Lu, Yunpeng Lee, Richmond Tan, Choon-Hong (Guanidine) copper complex-catalyzed enantioselective dynamic kinetic allylic alkynylation under biphasic condition |
| title | (Guanidine) copper complex-catalyzed enantioselective dynamic kinetic allylic alkynylation under biphasic condition |
| title_full | (Guanidine) copper complex-catalyzed enantioselective dynamic kinetic allylic alkynylation under biphasic condition |
| title_fullStr | (Guanidine) copper complex-catalyzed enantioselective dynamic kinetic allylic alkynylation under biphasic condition |
| title_full_unstemmed | (Guanidine) copper complex-catalyzed enantioselective dynamic kinetic allylic alkynylation under biphasic condition |
| title_short | (Guanidine) copper complex-catalyzed enantioselective dynamic kinetic allylic alkynylation under biphasic condition |
| title_sort | guanidine copper complex catalyzed enantioselective dynamic kinetic allylic alkynylation under biphasic condition |
| topic | Science::Chemistry Guanidine Anions |
| url | https://hdl.handle.net/10356/137033 |
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