20190-03-8Relevant articles and documents
Crystal chemistry of 1:1 molecular complexes of carbamate salts formed by slow aerial carbonation of amines
Mondal, Raju,Bhunia, Manas Kumar
, p. 787 - 792 (2008)
Amines do have rare tendency to undergo aerial carbonation to form carbamic acid. Four different 1:1 molecular complex of carbamate salts reported herein obtained by the aerial carbonation of cyclic amines. X-ray crystal structures show a systematic change in the molecular structure did bring some gradual supramolecular change from one structural motif to another.
Indirect conversion of ambient pressure CO2 into oxazolidin-2-ones by a copper-based magnetic nanocatalyst
Cheng, Bin-Bin,Yu, Bing,Hu, Chang-Wen
, p. 87179 - 87187 (2016)
An efficient, practical and magnetically recyclable Cu-based catalytic system for the synthesis of oxazolidin-2-ones via the multicomponent reaction of carbamate salts, aromatic aldehydes and aromatic terminal alkynes was developed. The magnetic nanocatalyst, namely FeDOPACu, could efficiently promote the construction of oxazolidin-2-ones with different functional groups in good to excellent yields. Importantly, the catalyst can be easily recovered by applying an external magnet, which rendered this protocol economic and environmentally begin. This method represents an attractive heterogeneous protocol for indirect transformation of CO2 into value-added heterocyles as the carbamate salts are easily obtained by capturing CO2 with primary amines.
Atmospheric Pressure of CO2 as Protecting Reagent and Reactant: Efficient Synthesis of Oxazolidin-2-ones with Carbamate Salts, Aldehydes and Alkynes
Yu, Bing,Cheng, Bin-Bin,Liu, Wei-Qi,Li, Wei,Wang, Shan-Shan,Cao, Jie,Hu, Chang-Wen
, p. 90 - 97 (2016)
Carbon dioxide (CO2) has been wildly employed as an environmentally benign C1 resource for organic synthesis in the recent years. The capture of CO2 with primary amines easily provides the corresponding carbamate salts. We described herein that carbamate salts are a useful reactant for the synthesis of oxazolidin-2-ones via the reaction with aromatic aldehydes and aromatic terminal alkynes. A variety of oxazolidin-2-ones with different functional groups were synthesized in 68-91% yields with only a 5 mol% amount of CuI as catalyst. It was found that the synergetic effect of iodide is important for the transformation. Notable, the captured CO2 serves not only as a protecting reagent for electron-rich primary amine to avoid catalyst poisoning, but also as a reactant for the construction of oxazolidin-2-ones.
Cooperative Catalysis of Ru(III)-Porphyrin in CO2-Involved Synthesis of Oxazolidinones
Chen, Xiao-Chao,Yao, Yin-Qing,Zhao, Kai-Chun,Liu, Lei,Lu, Yong,Liu, Ye
, p. 2504 - 2510 (2021/07/28)
CO2-transformations into high value-added products have become a fascinating area in green chemistry. Herein, a Ru(III)-porphyrin catalyst (RuCl3 ? 3H2O?H2TPP) was found highly efficient in the three-component reaction of CO2, aliphatic amines and dichloroethane (or its derivative) for synthesis of oxazolidinones in the yields of 71～91%. It was indicated by means of the control experiments and UV-vis spectra that CO2 was stoichiometrically activated by the involved aliphatic amine substrates to form a stable carbamate salt while 1,2-dichloroethane (or its derivative) was independently activated by the involved Ru(III)-porphyrin catalyst. The combination of CO2-activation by aliphatic amines with 1,2-dichloroethane activation by Ru(III)-porphyrin catalyst cooperatively contributed to this successful transformation.
Direct NHC-catalysed redox amidation using CO2 for traceless masking of amine nucleophiles
Davidson, Robert W. M.,Fuchter, Matthew J.
supporting information, p. 11638 - 11641 (2016/10/04)
The N-heterocyclic carbene (NHC)-catalysed redox amidation reaction is poorly developed and usually requires catalytic co-additives for electron-rich amine nucleophiles. We report a masking strategy (using CO2) that couples release of the free amine nucleophile to catalytic turnover, and in doing so, enables direct catalytic redox amidation of electron-rich amines.
Organocatalytic knoevenagel condensations by means of carbamic acid ammonium salts
Mase, Nobuyuki,Horibe, Takuya
supporting information, p. 1854 - 1857 (2013/06/04)
The Knoevenagel condensation between an active methylene compound and an aromatic aldehyde with a carbamic acid ammonium salt used as an organocatalyst gave the desired Knoevenagel products in up to 98% yield. The reaction occurred at rt and in a short reaction time under solvent-free conditions. In addition, no extraction, wash, or chromatography steps were needed to obtain a high-purity Knoevenagel product.
Synthesis of urea derivatives from amines and CO2 in the absence of catalyst and solvent
Wu, Chaoyong,Cheng, Haiyang,Liu, Ruixia,Wang, Qiang,Hao, Yufen,Yu, Yancun,Zhao, Fengyu
body text, p. 1811 - 1816 (2011/02/22)
Urea derivatives are obtained in mild to good yield from the reactions of primary aliphatic amines with CO2 in the absence of any catalysts, organic solvents or other additives. To optimize reaction conditions, experimental variables including temperature, pressure, the concentration of amine, reaction time etc. were studied. Satisfactory yields were obtained at the optimized conditions that are comparable to the presence of catalyst and solvent. The preliminary investigation of the reaction mechanism showed that alkyl ammonium alkyl carbamate was quickly formed as the intermediate, and then the final product was formed by the intramolecular dehydration.
Reaction of Alkali-metal Tetraphenylborates with Amines in the Presence of CO2: a New Easy Way to Aliphatic and Aromatic Alkali-metal Carbamates
Aresta, Michele,Dibenedetto, Angela,Quaranta, Eugenio
, p. 3359 - 3364 (2007/10/03)
A new method of synthesis of both aliphatic and aromatic alkali-metal carbamates and anhydrous alkylammonium tetraphenylborates by reaction, at room temperature, of amines with alkali-metal tetraphenylborates in the presence of CO2 (0.1 MPa) has been determined.This reaction represents the first step of a new very selective synthetic route to alkali-metal carbamates from amines, carbon dioxide and alkali-metal hydroxides at room temperature and pressure.It is also the first example of the isolation of aromatic amine alkali-metal carbamates through a non-isocyanate route.
Role of the macrocyclic polyether in the synthesis of N-alkylcarbamate ester from primary amines, CO2 and alkyl halides in the presence of crown-ethers
Aresta,Quaranta
, p. 1515 - 1530 (2007/10/02)
Primary amines, RNH2 1, and CO2 easily afford monoalkylammonium N-alkylcarbamates, [RNH3][O2CNHR] 2, that have been reacted with alkyl halides, R'X, in the presence of crown-ethers to give organic carbamates in good yield. We report here the synthesis and spectroscopic characterization of some alkylammonium carbamates 2, where R - benzyl 2a, allyl 2b, ter-butyl 2c, cyclohexyl 2d, and discuss their stability in solution and the conditions in which they can react with alkyl halides to give organic carbamates, RNHC(O)OR'. The role played by the macrocyclic ligand in modifying the reactivity of monoalkylammonium carbamates 2 towards R'X has been rationalized and the influence of parameters such as solvent, temperature and CO2 pressure on the yield and selectivity of the process leading to organic carbamates has been also settled.
Mechanistic Studies on the Role of Carbon Dioxide in the Synthesis of Methylcarbamates from Amines and Dimethylcarbonate in the Presence of CO2
Aresta, Michele,Quaranta, Eugenio
, p. 9489 - 9502 (2007/10/02)
N-Alkylmethylcarbamates have been synthesized from amines and dimethylcarbonate (DMC) in the presence of carbon dioxide.The catalytic role of CO2 in the overall process has been investigated and elucidated.Key words: carbon dioxide; organic carbamates; dimethylcarbonate; carbamic-carbonic anhydride
