6744-65-6Relevant articles and documents
A substituent- And temperature-controllable NHC-derived zwitterionic catalyst enables CO2upgrading for high-efficiency construction of formamides and benzimidazoles
Li, Hu,Li, Zhengyi,Wu, Hongguo,Yang, Song,Yu, Zhaozhuo,Zhang, Lilong,Zhu, Kaixun
supporting information, p. 5759 - 5765 (2021/08/23)
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.
An efficient way for the: N -formylation of amines by inorganic-ligand supported iron catalysis
Wu, Zhikang,Zhai, Yongyan,Zhao, Wenshu,Wei, Zheyu,Yu, Han,Han, Sheng,Wei, Yongge
supporting information, p. 737 - 741 (2020/02/25)
The first example of an inorganic-ligand supported iron(iii) catalysed coupling of formic acid and amines to form formamides is reported. The pure inorganic catalyst (NH4)3[FeMo6O18(OH)6] (1), which consists of a central FeIII single-atomic core supported within a cycle-shaped inorganic ligand consisting of six MoVIO6 octahedra, shows excellent activity and selectivity, and avoids the use of complicated/commercially unavailable organic ligands. Various primary amines and secondary amines have been successfully transformed into the corresponding formamides under mild conditions, and the formylation of primary diamines has also been achieved for the first time. The Fe catalyst 1 can be reused several times without appreciable loss of activity.
Metal-free Carbon Monoxide (CO) Capture and Utilization: Formylation of Amines
Noh, Hyeong-Wan,An, Youngjoon,Lee, Seulchan,Jung, Jaehoon,Son, Seung Uk,Jang, Hye-Young
, (2019/04/26)
The capture and utilization of CO by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) were performed in the absence of transition-metal complexes. The reaction of TBD with CO afforded TBD-CO adducts, which were converted to formylated TBD (TBD-CHO). TBD-CO adducts may include an interaction of CO with positively charged species based on NMR and IR analysis. In the presence of amines, CO was transferred from TBD-CO to amines, producing formylated amines with good yields. The reaction mechanism involving TBD-CO adducts is presented based on theoretical calculations. (Figure presented.).
