Similarities and Differences between Site-Selective Acylation and Phosphorylation of Amphiphilic Diols, Promoted by Nucleophilic Organocatalysts Decorated with Outer-Sphere Appendages
We demonstrated recently that organocatalysts, based on a nucleophilic core (N-alkylimidazole or 4-aminopyridine) and decorated with an extensive secondary-sphere envelope (connected to the core through a benzyl substituent), strongly affect the site selectivity in acylation and phosphorylation of a...
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MDPI AG
2023-02-01
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| author | Or Fleischer Tom Targel Fatma Saady Moshe Portnoy |
| author_facet | Or Fleischer Tom Targel Fatma Saady Moshe Portnoy |
| author_sort | Or Fleischer |
| collection | DOAJ |
| description | We demonstrated recently that organocatalysts, based on a nucleophilic core (N-alkylimidazole or 4-aminopyridine) and decorated with an extensive secondary-sphere envelope (connected to the core through a benzyl substituent), strongly affect the site selectivity in acylation and phosphorylation of amphiphilic diols, sometimes entirely overriding the innate predisposition of the substrate. Preliminary studies pointed out that, despite some similarities, there are differences between the two transformations, regarding the influence of various catalyst features on the selectivity. To fully elucidate this, extended families of organocatalysts of the said design were examined, activity- and selectivity-wise, in the abovementioned transformations of model alcohol and amphiphilic diol substrates. A comparison of the influence of the catalyst design on the two reactions revealed that while the inductive electron donation of the <i>o</i>,<i>o</i>-dialkoxybenzyl substituent of the core, combined with the catalytic intermediate-stabilizing influence of some of the secondary-sphere components, causes an increase in the catalyst activity in both reactions and in the site selectivity in phosphorylation, its effect on the site selectivity in acylation is opposite. On the other hand, the lipophilicity of the secondary-sphere appendages improves the apolar site-favoring selectivity in both reactions. Thus, both factors work in concert in phosphorylation, but in opposite directions in acylation. |
| first_indexed | 2024-03-11T09:00:50Z |
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| id | doaj.art-59399740be4f4fb990bdbf9f3a44f27c |
| institution | Directory Open Access Journal |
| issn | 2073-4344 |
| language | English |
| last_indexed | 2024-03-11T09:00:50Z |
| publishDate | 2023-02-01 |
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| series | Catalysts |
| spelling | doaj.art-59399740be4f4fb990bdbf9f3a44f27c2023-11-16T19:42:04ZengMDPI AGCatalysts2073-43442023-02-0113236110.3390/catal13020361Similarities and Differences between Site-Selective Acylation and Phosphorylation of Amphiphilic Diols, Promoted by Nucleophilic Organocatalysts Decorated with Outer-Sphere AppendagesOr Fleischer0Tom Targel1Fatma Saady2Moshe Portnoy3School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, IsraelSchool of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, IsraelSchool of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, IsraelSchool of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, IsraelWe demonstrated recently that organocatalysts, based on a nucleophilic core (N-alkylimidazole or 4-aminopyridine) and decorated with an extensive secondary-sphere envelope (connected to the core through a benzyl substituent), strongly affect the site selectivity in acylation and phosphorylation of amphiphilic diols, sometimes entirely overriding the innate predisposition of the substrate. Preliminary studies pointed out that, despite some similarities, there are differences between the two transformations, regarding the influence of various catalyst features on the selectivity. To fully elucidate this, extended families of organocatalysts of the said design were examined, activity- and selectivity-wise, in the abovementioned transformations of model alcohol and amphiphilic diol substrates. A comparison of the influence of the catalyst design on the two reactions revealed that while the inductive electron donation of the <i>o</i>,<i>o</i>-dialkoxybenzyl substituent of the core, combined with the catalytic intermediate-stabilizing influence of some of the secondary-sphere components, causes an increase in the catalyst activity in both reactions and in the site selectivity in phosphorylation, its effect on the site selectivity in acylation is opposite. On the other hand, the lipophilicity of the secondary-sphere appendages improves the apolar site-favoring selectivity in both reactions. Thus, both factors work in concert in phosphorylation, but in opposite directions in acylation.https://www.mdpi.com/2073-4344/13/2/361alcoholsorganocatalysissite selectivityacylationphosphorylationsecondary-sphere interactions |
| spellingShingle | Or Fleischer Tom Targel Fatma Saady Moshe Portnoy Similarities and Differences between Site-Selective Acylation and Phosphorylation of Amphiphilic Diols, Promoted by Nucleophilic Organocatalysts Decorated with Outer-Sphere Appendages Catalysts alcohols organocatalysis site selectivity acylation phosphorylation secondary-sphere interactions |
| title | Similarities and Differences between Site-Selective Acylation and Phosphorylation of Amphiphilic Diols, Promoted by Nucleophilic Organocatalysts Decorated with Outer-Sphere Appendages |
| title_full | Similarities and Differences between Site-Selective Acylation and Phosphorylation of Amphiphilic Diols, Promoted by Nucleophilic Organocatalysts Decorated with Outer-Sphere Appendages |
| title_fullStr | Similarities and Differences between Site-Selective Acylation and Phosphorylation of Amphiphilic Diols, Promoted by Nucleophilic Organocatalysts Decorated with Outer-Sphere Appendages |
| title_full_unstemmed | Similarities and Differences between Site-Selective Acylation and Phosphorylation of Amphiphilic Diols, Promoted by Nucleophilic Organocatalysts Decorated with Outer-Sphere Appendages |
| title_short | Similarities and Differences between Site-Selective Acylation and Phosphorylation of Amphiphilic Diols, Promoted by Nucleophilic Organocatalysts Decorated with Outer-Sphere Appendages |
| title_sort | similarities and differences between site selective acylation and phosphorylation of amphiphilic diols promoted by nucleophilic organocatalysts decorated with outer sphere appendages |
| topic | alcohols organocatalysis site selectivity acylation phosphorylation secondary-sphere interactions |
| url | https://www.mdpi.com/2073-4344/13/2/361 |
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