A substituent- and temperature-controllable NHC-derived zwitterionic catalyst enables CO2 upgrading for high-efficiency construction of formamides and benzimidazoles
| العنوان: | A substituent- and temperature-controllable NHC-derived zwitterionic catalyst enables CO2 upgrading for high-efficiency construction of formamides and benzimidazoles |
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| المؤلفون: | Song Yang, Hongguo Wu, Zhaozhuo Yu, Kaixun Zhu, Hu Li, Li-Long Zhang, Zhengyi Li |
| المصدر: | Green Chemistry. 23:5759-5765 |
| بيانات النشر: | Royal Society of Chemistry (RSC), 2021. |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | chemistry.chemical_classification, Decarboxylation, Hydrosilylation, Substituent, Pollution, Combinatorial chemistry, Catalysis, chemistry.chemical_compound, chemistry, Nucleophile, Environmental Chemistry, Amine gas treating, Formamides, Alkyl |
| الوصف: | Chemocatalytic upgrading of the greenhouse gas CO2 to valuable chemicals and biofuels has attracted broad attention in recent years. Among the reported approaches, N-formylation of CO2 with an amine is of great significance due to its versatility in the construction of N-containing linear and cyclic skeletons. Herein, a stable N-heterocyclic carbene-carboxyl adduct (NHC-CO2) was facilely prepared and could be used as a recyclable zwitterionic catalyst for efficient CO2 reductive upgrading via either N-formylation or further coupling with cyclization under mild conditions (25 °C, 1 atm CO2) using hydrosilane as a hydrogen source. More than 30 different alkyl and aromatic amines could be transformed into the corresponding formamides or benzimidazoles with remarkable yields (74%–98%). The electronic effect of the introduced substituent on NHC-CO2 was found to evidently affect the thermostability and nucleophilicity of the zwitterionic catalyst, which is directly correlated with its catalytic activity. Moreover, NHC-CO2 could supply CO2 by in situ decarboxylation at a specific temperature that is dependent on the introduced substituent type. Experimental and computational studies showed that the carboxyl species on NHC-CO2 was not only a nucleophilic center, but also a C1 source which rapidly captures or substitutes ambient CO2 during hydrosilylation. In addition, a simple and green conceptual process was designed for the product purification and catalyst recycling, with a good feasibility for small-scale production. |
| تدمد: | 1463-9270 1463-9262 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::5b3fc3ff96b5553afa8243678ff83f65 https://doi.org/10.1039/d1gc01897c |
| حقوق: | CLOSED |
| رقم الأكسشن: | edsair.doi...........5b3fc3ff96b5553afa8243678ff83f65 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14639270 14639262 |
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