A substituent- and temperature-controllable NHC-derived zwitterionic catalyst enables CO2 upgrading for high-efficiency construction of formamides and benzimidazoles was written by Yu, Zhaozhuo;Li, Zhengyi;Zhang, Lilong;Zhu, Kaixun;Wu, Hongguo;Li, Hu;Yang, Song. And the article was included in Green Chemistry in 2021.Recommanded Product: 1-Methylbenzimidazole This article mentions the following:
Chemocatalytic upgrading of the greenhouse gas CO2 to valuable chems. 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. Exptl. 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 In the experiment, the researchers used many compounds, for example, 1-Methylbenzimidazole (cas: 1632-83-3Recommanded Product: 1-Methylbenzimidazole).
1-Methylbenzimidazole (cas: 1632-83-3) belongs to imidazole derivatives. Many natural products, especially alkaloids, contain the imidazole ring. These imidazoles share the 1,3-C3N2 ring but feature varied substituents. The pharmacophore of imidazole exists in bioactive compounds including amino acids, plant growth regulators and therapeutic agents.n increase of the alkyl chain length of the alcohols. Recommanded Product: 1-Methylbenzimidazole
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem