- Synergetic activation of CO2by the DBU-organocatalyst and amine substrates towards stable carbamate salts for synthesis of oxazolidinones
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The development of an efficient methodology to transform CO2 into valuable chemicals has attracted increasing attention concerning the challenging issues of CO2-utilization. Herein, an efficient approach for the preparation of oxazolidinones from CO2, primary (aliphatic/aromatic) amines and 1,2-dichloroethane (or its derivatives) catalyzed by DBU organo-superbase was achieved with yields of 47-97% under mild conditions (80-100 °C, 12 h, 1.0 MPa CO2). Control experiments demonstrated that the formation of an ion-pair carbamate salt intermediate IS-B derived from the reaction of CO2, DBU (catalyst) and an amine (substrate) was the key step for this three-component reaction. The available DBU-amine-CO2 adduct intermediate (like IS-B-2) with fair stability will evolve into the thermodynamically stable product oxazolidinones upon attack of 1,2-dichloroethane (or its derivatives), along with the regeneration of the DBU catalyst. Alternatively, the decomposition of the DBU-aryl amine-CO2 adduct (like IS-B-1) with relatively poor stability also could result in the competitive substitution reaction of 1,2-dichloroethane (or its derivatives) with the aryl amine. This work provides insights into synergetic CO2-activation by the DBU-catalyst and a nucleophilic amine-substrate via the formation of robust carbamate salt intermediates responsible for the final production of oxazolidinones. This journal is
- Chen, Xiao-Chao,Liu, Ye,Lu, Yong,Yao, Yin-Qing,Zhao, Kai-Chun
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p. 7072 - 7082
(2021/11/17)
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- Synthesis of Oxazolidinones and Derivatives through Three-Component Fixation of Carbon Dioxide
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An effective three-component fixation of atmospheric CO2 with readily available 1,2-dichloroethane and aromatic amine toward oxazolidinones catalyzed by in situ NHC was developed. The reaction occurred in good to excellent yields with good gene
- Mei, Congmin,Zhao, Yibo,Chen, Qianwei,Cao, Changsheng,Pang, Guangsheng,Shi, Yanhui
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p. 3057 - 3068
(2018/06/04)
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- Synthesis of N-aryl-2-oxazolidinones from cyclic carbonates and aromatic amines catalyzed by bio-catalyst
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A convenient and effective method of synthesizing 3-aryl-2-oxazolidinones from cyclic carbonates and aryl amines catalyzed by bio-catalyst adenine in the presence of Et3N under solvent-free conditions is described. The protocol is suitable for the wide scope of substrates, e.g. cyclic carbonates with or without substitutes, and aryl amines with either electron-withdrawing or electron-donating group. The products were obtained in good to excellent yields under the optimal conditions, even in steric hindered cases. The effect of reaction time, temperature, loading of catalyst, and amount of starting materials in the reaction were investigated, and the reaction mechanism is discussed.
- Mei, Congmin,Zhao, Yibo,Zou, Ke,Cao, Changsheng,Pang, Guangsheng,Shi, Yanhui
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p. 2179 - 2194
(2017/12/28)
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- DBU and DBU-Derived Ionic Liquid Synergistic Catalysts for the Conversion of Carbon Dioxide/Carbon Disulfide to 3-Aryl-2-oxazolidinones/[1,3]Dithiolan-2-ylidenephenyl- Amine
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An intermolecular synergistic catalytic combination of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and a DBU-derived bromide ionic liquid has been developed for the conversion of CO2, epoxides, and amines under metal- And solvent-free conditions. Various 3-aryl-2-oxazolidinones are produced in moderate to excellent yields within a short reaction time. NMR spectroscopy and DFT calculations demonstrate that DBU as a hydrogen bond acceptor and the ionic liquid as a hydrogen bond donor activate the substrates cooperatively by inducing hydrogen bonds to promote the reaction effectively. Based on these results, a possible reaction mechanism on the synergistic catalysis of DBU and the ionic liquid is proposed. In addition, the reaction of CS2, ethylene oxide, and aniline catalyzed by the combination of DBU and the DBU-derived ionic liquid also proceeds smoothly, which opens a hitherto unreported route to [1,3]dithiolan-2-ylidenephenylamine in a straightforward way.
- Wang, Binshen,Luo, Zhoujie,Elageed, Elnazeer H. M.,Wu, Shi,Zhang, Yongya,Wu, Xiaopei,Xia, Fei,Zhang, Guirong,Gao, Guohua
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p. 830 - 838
(2016/03/05)
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- BmimOAc ionic liquid: A highly efficient catalyst for synthesis of 3-aryl-2-oxazolidinones by direct condensation of 2-(arylamino) alcohols with diethyl carbonate
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An efficient convenient procedure for the synthesis of 3-aryl-2-oxazolidinones from 2-(arylamino) alcohols and diethyl carbonate (DEC) catalyzed by ionic liquids is described. The effects of reaction time, amount of catalyst and temperature were investigated. Excellent yields of products were obtained under the optimized reaction conditions, when using BmimOAc as a catalyst. An intermediate ethyl 2-(phenyl amino) ethyl carbonate was isolated and characterized. 1H NMR spectroscopy and DFT calculations indicated that BmimOAc cooperatively activate the substrates through hydrogen bonding with its anion and cation sites. According to these results, a possible reaction mechanism was discussed.
- Elageed, Elnazeer H.M.,Wang, Binshen,Zhang, Yongya,Wu, Shi,Gao, Guohua
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p. 271 - 277
(2015/09/01)
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- One-pot conversion of carbon dioxide, ethylene oxide, and amines to 3-aryl-2-oxazolidinones catalyzed with binary ionic liquids
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An effective one-pot method for the conversion of carbon dioxide, ethylene oxide, and amines to 3-aryl-2-oxazolidinones has been developed. This one-pot method consists of two parallel reactions and a subsequent cascade reaction between the two products of the corresponding parallel reactions. Notably, the binary ionic liquids of 1-butyl-3-methyl-imidazolium bromide and 1-butyl-3-methyl-imidazolium acetate demonstrate a synergistic catalytic effect on this new strategy. 1-Butyl-3-methyl-imidazolium bromide is essential in two parallel reactions owing to the good nucleophilicity and leaving ability of bromide, and 1-butyl-3-methyl-imidazolium acetate plays a dominant role in the subsequent cascade reaction owing to the strong basicity of acetate. In addition, the binary ionic liquids can be used thrice without significant loss of catalytic activity. Copyright
- Wang, Binshen,Elageed, Elnazeer H.M.,Zhang, Dawei,Yang, Sijuan,Wu, Shi,Zhang, Guirong,Gao, Guohua
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p. 278 - 283
(2014/01/23)
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- Copper-Catalyzed One-Pot Synthesis of N -Aryl Oxazolidinones from Amino Alcohol Carbamates
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An efficient sequential intramolecular cyclization of amino alcohol carbamates followed by Cu-catalyzed cross-coupling with aryl iodides under mild conditions has been developed. The reaction occurred in good yields and tolerated aryl iodides containing functionalities such as nitriles, ketones, ethers, and halogens. Heteroaryl iodides and substituted amino alcohol carbamates were also well tolerated.
- Mahy, William,Plucinski, Pawel K.,Frost, Christopher G.
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supporting information
p. 5020 - 5023
(2015/01/08)
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- Copper-catalyzed N-arylation of 2-oxazolidinones. An expeditious route to toloxatone
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3-Aryl-2-oxazolidinones are obtained in excellent yields through the copper-catalyzed N-arylation of 2-oxazolidinones with a variety of aryl iodides. With aryl halides containing both iodo and bromo substituents, a high C-I/C-Br selectivity can be achieved. The procedure has been successfully applied to the preparation of a key intermediate in the synthesis of linezolid and to develop an expeditious route to toloxatone.
- Cacchi, Sandro,Fabrizi, Giancarlo,Goggiamani, Antonella
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p. 505 - 512
(2007/10/03)
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- 3-Aryl-2-oxazolidinones through the palladium-catalyzed N-arylation of 2-oxazolidinones.
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[reaction: see text] 3-Aryl-2-oxazolidinones are obtained in good yields through the palladium-catalyzed N-arylation of 2-oxazolidinones with aryl bromides. The nature of aryl bromides, phosphine ligands, bases, and solvents strongly affects the reaction
- Cacchi,Fabrizi,Goggiamani,Zappia
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p. 2539 - 2541
(2007/10/03)
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- A novel phosphate protection for oligonucleotide synthesis: The 2-[(1- naphthyl)carbamoyloxy]ethyl (NCE) group
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The utility of the 2-(arylcarbamoyloxy)ethyl group for protection of internucleosidic phosphate linkages in oligonucleotide synthesis was studied. Of the three protecting groups tested, the 2-[(1-naphthyl)carbamoyloxy]ethyl demonstrated high coupling yields, favorable deprotection kinetics and the highest hydrolytic stability of the thymidine phosphoramidite building block. The mechanism of deprotection was confirmed by deprotecting a model phosphate triester and synthetic dodecathymidylate. (C) 2000 Elsevier Science Ltd.
- Guzaev, Andrei P.,Manoharan, Muthiah
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p. 5623 - 5626
(2007/10/03)
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- Investigation of aryl oxazolidinones and aryl thiazolidinethiones by NMR spectroscopy
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The 1H and 13C resonances of 3-aryl-2-oxazolidinones and 3-aryl-2-thiazolidinethiones have been examined.The conformational isomers of restricted rotation about the aryl C-N bond could not be detected for both of the nuclei.The additive shift parameters, measured for carbon chemical shifts, are found to be higher in the sulphur substituted hetero ring.
- Aksac, Z.,Altinok, A.,Icli, S.
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p. 1029 - 1032
(2007/10/02)
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