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Asymmetric Synthesis of Bicyclic Pyrazolidinones through Alkaloid‐Catalyzed [3+2]‐Cycloadditions of Ketenes and Azomethine Imines
A versatile asymmetric synthesis of bicyclic pyrazolidinones through alkaloid‐catalyzed formal [3+2]‐ and [3+2+2]‐cycloadditions of ketenes with azomethine imines is described. The methodology was found to be tolerant of ketene and a variety of monosubstituted ketenes (R=alkyl, OAc). The products we...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9311188/ https://www.ncbi.nlm.nih.gov/pubmed/35175649 http://dx.doi.org/10.1002/chem.202104391 |
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author | Mondal, Mukulesh Mitra, Shubhanjan Twardy, Dylan J. Panda, Manashi Wheeler, Kraig A. Kerrigan, Nessan J. |
author_facet | Mondal, Mukulesh Mitra, Shubhanjan Twardy, Dylan J. Panda, Manashi Wheeler, Kraig A. Kerrigan, Nessan J. |
author_sort | Mondal, Mukulesh |
collection | PubMed |
description | A versatile asymmetric synthesis of bicyclic pyrazolidinones through alkaloid‐catalyzed formal [3+2]‐ and [3+2+2]‐cycloadditions of ketenes with azomethine imines is described. The methodology was found to be tolerant of ketene and a variety of monosubstituted ketenes (R=alkyl, OAc). The products were formed in good to excellent yields (71–99 % for 24 examples, 39 examples in all), with good to excellent diastereoselectivity in many cases (dr 3 : 1 to 27 : 1 for 22 examples), and with excellent enantioselectivity for most examples (≥93 % ee for 34 products). In the case of most disubstituted ketenes, the reaction proceeded through a [3+2+2]‐cycloaddition to form structurally interesting bicyclic pyrazolo‐oxadiazepinediones with moderate diastereoselectivity (dr up to 3.7 : 1) and as racemic mixtures (3 examples). The method represents the first unambiguous example of an enantioselective reaction between ketenes and a 1,3‐dipole. |
format | Online Article Text |
id | pubmed-9311188 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-93111882022-07-29 Asymmetric Synthesis of Bicyclic Pyrazolidinones through Alkaloid‐Catalyzed [3+2]‐Cycloadditions of Ketenes and Azomethine Imines Mondal, Mukulesh Mitra, Shubhanjan Twardy, Dylan J. Panda, Manashi Wheeler, Kraig A. Kerrigan, Nessan J. Chemistry Research Articles A versatile asymmetric synthesis of bicyclic pyrazolidinones through alkaloid‐catalyzed formal [3+2]‐ and [3+2+2]‐cycloadditions of ketenes with azomethine imines is described. The methodology was found to be tolerant of ketene and a variety of monosubstituted ketenes (R=alkyl, OAc). The products were formed in good to excellent yields (71–99 % for 24 examples, 39 examples in all), with good to excellent diastereoselectivity in many cases (dr 3 : 1 to 27 : 1 for 22 examples), and with excellent enantioselectivity for most examples (≥93 % ee for 34 products). In the case of most disubstituted ketenes, the reaction proceeded through a [3+2+2]‐cycloaddition to form structurally interesting bicyclic pyrazolo‐oxadiazepinediones with moderate diastereoselectivity (dr up to 3.7 : 1) and as racemic mixtures (3 examples). The method represents the first unambiguous example of an enantioselective reaction between ketenes and a 1,3‐dipole. John Wiley and Sons Inc. 2022-03-14 2022-04-12 /pmc/articles/PMC9311188/ /pubmed/35175649 http://dx.doi.org/10.1002/chem.202104391 Text en © 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH https://creativecommons.org/licenses/by/4.0/This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Articles Mondal, Mukulesh Mitra, Shubhanjan Twardy, Dylan J. Panda, Manashi Wheeler, Kraig A. Kerrigan, Nessan J. Asymmetric Synthesis of Bicyclic Pyrazolidinones through Alkaloid‐Catalyzed [3+2]‐Cycloadditions of Ketenes and Azomethine Imines |
title | Asymmetric Synthesis of Bicyclic Pyrazolidinones through Alkaloid‐Catalyzed [3+2]‐Cycloadditions of Ketenes and Azomethine Imines |
title_full | Asymmetric Synthesis of Bicyclic Pyrazolidinones through Alkaloid‐Catalyzed [3+2]‐Cycloadditions of Ketenes and Azomethine Imines |
title_fullStr | Asymmetric Synthesis of Bicyclic Pyrazolidinones through Alkaloid‐Catalyzed [3+2]‐Cycloadditions of Ketenes and Azomethine Imines |
title_full_unstemmed | Asymmetric Synthesis of Bicyclic Pyrazolidinones through Alkaloid‐Catalyzed [3+2]‐Cycloadditions of Ketenes and Azomethine Imines |
title_short | Asymmetric Synthesis of Bicyclic Pyrazolidinones through Alkaloid‐Catalyzed [3+2]‐Cycloadditions of Ketenes and Azomethine Imines |
title_sort | asymmetric synthesis of bicyclic pyrazolidinones through alkaloid‐catalyzed [3+2]‐cycloadditions of ketenes and azomethine imines |
topic | Research Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9311188/ https://www.ncbi.nlm.nih.gov/pubmed/35175649 http://dx.doi.org/10.1002/chem.202104391 |
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