14924-70-0Relevant academic research and scientific papers
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.
N-aryl formamide prepared by using ethyl bromodifluoroacetate as formylating reagent
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Paragraph 0032, (2018/12/02)
The invention discloses a compound of N-aryl formamide prepared by using ethyl bromodifluoroacetate as a formylating reagent. The compound is prepared by using N-alkyl arylamine as a raw material, ethyl bromodifluoroacetate as a formylating reagent and copper as a catalyst, adding different ligands, bases, etc., performing reaction under stirring in a reaction solvent at 100-120 DEG C for 10-14 hours; then filtering the reaction solution to obtain filtrate after reaction ending; concentrating the filtrate, removing the solvent by using a rotary evaporator to obtain a residue, treating the residue by silica gel column chromatography, eluting with an eluent, collecting the effluent according to the actual gradient; combining the effluent containing the product, concentrating the combined effluent to remove the solvent, and performing vacuum drying to obtain the target product. The compound has the advantages of simple and easily obtained raw materials, simple preparation process, less pollution, low energy consumption and high yield.
Copper-Catalyzed N-Formylation of Amines through Tandem Amination/Hydrolysis/Decarboxylation Reaction of Ethyl Bromodifluoroacetate
Li, Xiao-Fang,Zhang, Xing-Guo,Chen, Fan,Zhang, Xiao-Hong
, p. 12815 - 12821 (2018/10/20)
Ethyl bromodifluoroacetate (BrCF2COOEt) was first used as the N-formylating reagent in the copper-catalyzed N-formylation of amines. A range of primary, secondary, cyclic arylamines, and aliphatic amines underwent the N-formylation smoothly to furnish the N-formamides in moderate-to-excellent yields.
CO2 as a C1-building block for the catalytic methylation of amines
Jacquet, Olivier,Frogneux, Xavier,Das Neves Gomes, Christophe,Cantat, Thibault
, p. 2127 - 2131 (2013/05/21)
A novel catalytic reaction has been designed to utilize, for the first time, CO2 as a C1 feedstock in the synthesis of N-methylamines. Simple zinc catalysts, based on commercially available zinc salts and ligands, prove highly efficient in promoting both a 6 electron reduction of carbon dioxide and the formation of a C-N bond, using hydrosilanes and amines.
Pd-catalyzed intermolecular amidation of aryl halides: The discovery that xantphos can be trans-chelating in a palladium complex
Yin, Jingjun,Buchwald, Stephen L.
, p. 6043 - 6048 (2007/10/03)
A general method for the intermolecular coupling of aryl halides and amides using a Xantphos/ Pd catalyst is described. This system displays good functional group compatibility, and the desired C-N bond forming process proceeds in good to excellent yields with 1-4 mol % of the Pd catalyst. Additionally, the arylation of sulfonamides, oxazolidinones, and ureas is reported. The efficiency of these transformations was found to be highly dependent on reaction concentrations and catalyst loadings. A Pd complex resulting from oxidative addition of 4-bromobenzonitrile, (Xantphos)Pd(4-cyanophenyl)(Br) (II), was prepared in one step from Xantphos, Pd2(dba)3, and the aryl bromide. Complex II proved to be an active catalyst for the coupling between 4-bromobenzonitrile and benzamide. X-ray crystallographic analysis of II revealed a rare trans-chelating bisphosphine-Pd(II) structure with a large bite angle of 150.7°.
Palladium-catalyzed intermolecular coupling of aryl halides and amides
Yin, Jingjun,Buchwald, Stephen L.
, p. 1101 - 1104 (2007/10/03)
The first general intermolecular C-N bond-forming reactions between aryl halides and amides were realized using a palladium catalyst with Xantphos as the ligand. Aryl triflates, carbamates, and sulfonamides are also viable substrates for the amidations, which proceed at 45-110 °C with 1-4 mol% of Pd catalyst in 66-99% yields and exhibit good functional group compatibility.
