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: N-Cyclopropylformamide 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, N-Cyclopropylformamide (cas: 58644-54-5Recommanded Product: N-Cyclopropylformamide).
N-Cyclopropylformamide (cas: 58644-54-5) belongs to amides. Because of the greater electronegativity of oxygen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors. Amides can be freed from solvent or water by drying below their melting points. These purifications can also be used for sulfonamides and acid hydrazides.Recommanded Product: N-Cyclopropylformamide
Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics