1226-26-2Relevant academic research and scientific papers
Microwave-Assisted Electrostatically Enhanced Phenol-Catalyzed Synthesis of Oxazolidinones
Rostami, Ali,Ebrahimi, Amirhossein,Sakhaee, Nader,Golmohammadi, Farhad,Al-Harrasi, Ahmed
, p. 40 - 55 (2021/10/20)
An electrostatically enhanced phenol is utilized as a straightforward, sustainable, and potent one-component organocatalyst for the atom-economic transformation of epoxides to oxazolidinones under microwave irradiation. Integrating a positively charged center into phenols over a modular one-step preparation gives rise to a bifunctional system with improved acidity and activity, competent in rapid assembly of epoxides and isocyanates under microwave irradiation in a short reaction time (20-60 min). A careful assessment of the efficacy of various positively charged phenols and anilines and the impact of several factors, such as catalyst loading, temperature, and the kind of nucleophile, on catalytic reactivity were examined. Under neat conditions, this one-component catalytic platform was exploited to prepare more than 40 examples of oxazolidinones from a variety of aryl- and alkyl-substituted epoxides and isocyanates within minutes, where up to 96% yield and high degree of selectivity were attained. DFT calculations to achieve reaction barriers for different catalytic routes were conducted to provide mechanistic understanding and corroborated the experimental findings in which concurrent epoxide ring-opening and isocyanate incorporation were proposed.
Squaramide–Quaternary Ammonium Salt as an Effective Binary Organocatalytic System for Oxazolidinone Synthesis from Isocyanates and Epoxides
Rostami, Ali,Ebrahimi, Amirhossein,Husband, John,Anwar, Muhammad Usman,Csuk, Rene,Al-Harrasi, Ahmed
, p. 1881 - 1895 (2020/03/13)
Squaramide–quaternary ammonium salt is illustrated as a simple, tunable, and competent metal-free binary catalytic platform for the atom-economic conversion of epoxides and isocyanates into oxazolidinones. Although, various metal catalysts have been employed for the title reaction, application of organocatalysis is scarce. At first, a rational survey of catalytic activity of several air-stable and architecturally distinct squaramides was undertaken. Thereafter, the impact on catalytic capability of different parameters, such as temperature, catalyst loading, and nature of nucleophiles, was examined. This binary organocatalytic system for the oxazolidinone synthesis, composed of a squaramide entity along with a suitable halide anion, was applied to the challenging conversion of a plethora of alkyl- and aryl-substituted epoxides– including disubstituted and enantioenriched ones– and isocyanates into the corresponding oxazolidinones in high-to-excellent yields. The time-dependent formation of oxazolidinone from epoxide and isocyanate was monitored by FTIR-ATR and 1H NMR spectroscopy and the scalability of this process was also described. In light of 1H NMR experiment, a hydrogen-bonding/anion-binding mechanism was proposed wherein the nucleophilic ring-opening operation, and oxo- and carbamate-anions stabilization occur cooperatively towards isocyanate fixation.
Triethylamine Hydroiodide as a Bifunctional Catalyst for the Solvent-Free Synthesis of 2-Oxazolidinones
Nishiyori, Ryuichi,Okuno, Ken,Shirakawa, Seiji
, p. 4937 - 4941 (2020/07/30)
Among the wide variety of heterocycles, 2-oxazolidinones are recognized as some of the most important heterocyclic compounds in medicinal chemistry. Therefore, the development of a practical method for their synthesis would be an important development. He
A Multicomponent Approach to Oxazolidinone Synthesis Catalyzed by Rare-Earth Metal Amides
Zhou, Meixia,Zheng, Xizhou,Wang, Yaorong,Yuan, Dan,Yao, Yingming
, p. 5783 - 5787 (2019/04/14)
Three-component reaction of epoxides, amines, and dimethyl carbonate catalyzed by rare-earth metal amides has been developed to synthesize oxazolidinones. 47 examples of 3,5-disubstituted oxazolidinones were prepared in 13–97 % yields. This is a simple and most practical method which employs easily available substrates and catalysts, and is applicable to a wide range of aromatic and aliphatic amines, as well as mono-substituted epoxides. Scope of disubstituted epoxides is rather limited, which requires further study. Preliminary mechanistic study reveals two possible reaction pathways through intermediates of β-amino alcohols or amides.
Method for synthesizing N - aryl oxazolidine -2 - ketone compound by ionic liquid catalysis
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Paragraph 0031-0032; 0069-0070, (2019/10/01)
The invention discloses a method for catalytic synthesis of a N-aryloxazolane-2-one compound or a chiral N-aryloxazolane-2-one compound from an ionic liquid. The process of the preparation method is as follows: a catalytic amount of ionic liquid is added
Tetraarylphosphonium Salt-Catalyzed Synthesis of Oxazolidinones from Isocyanates and Epoxides
Toda, Yasunori,Gomyou, Shuto,Tanaka, Shoya,Komiyama, Yutaka,Kikuchi, Ayaka,Suga, Hiroyuki
supporting information, p. 5786 - 5789 (2017/11/10)
Preparation of a range of oxazolidinones, including enantioenriched N-aryl-substituted oxazolidinones, in which tetraarylphosphonium salts (TAPS) catalyze the [3 + 2] coupling reaction of isocyanates and epoxides effectively, is described. The key finding is a Br?nsted acid/halide ion bifunctional catalyst that can accelerate epoxide ring opening with high regioselectivity. Mechanistic studies disclosed that the ylide generated from TAPS, along with the formation of halohydrins, plays a crucial role in the reaction with isocyanates.
Isocyanurate Formation During Oxazolidinone Synthesis from Epoxides and Isocyanates Catalysed by a Chromium(Salphen) Complex
Wu, Xiao,Mason, Jess,North, Michael
, p. 12937 - 12943 (2017/09/25)
Chromium(salphen) complex 10 is found to be a catalyst for the preparation of oxazolidinones from epoxides and isocyanates. Using the optimal reaction conditions (1.5 mol % of chromium(salphen) complex 10 at 80 °C in toluene for 4 hours), six epoxides wer
Transformation of Carbon Dioxide into Oxazolidinones and Cyclic Carbonates Catalyzed by Rare-Earth-Metal Phenolates
Xu, Bin,Wang, Peng,Lv, Min,Yuan, Dan,Yao, Yingming
, p. 2466 - 2471 (2016/08/24)
Rare-earth-metal complexes stabilized by amine-bridged tri(phenolato) ligands were developed, and their activities in catalyzing transformations of CO2 were studied. A series of terminal epoxides and challenging disubstituted epoxides were converted into the respective cyclic carbonates in the presence of CO2 in yields of 58 to 96 %. In addition, these rare-earth-metal complexes also showed good activities in catalyzing three-component reactions of anilines, epoxides, and CO2, which generated 5-substituted-3-aryl-2-oxazolidines in yields of 48 to 96 %, as a useful strategy to construct oxazolidinones.
Selective Synthesis of 5-Substituted N-Aryloxazolidinones by Cycloaddition Reaction of Epoxides with Arylcarbamates Catalyzed by the Ionic Liquid BmimOAc
Elageed, Elnazeer H. M.,Chen, Bihua,Wang, Binshen,Zhang, Yongya,Wu, Shi,Liu, Xiuli,Gao, Guohua
supporting information, p. 3650 - 3656 (2016/07/28)
A selective procedure for the synthesis of 5-substituted N-aryloxazolidinones by the coupling of epoxides with arylcarbamates catalyzed by ionic liquids has been developed. The effects of reaction time, reactant molar ratio, amount of catalyst, and temper
Synthesis of Oxazolidinones from Epoxides and Isocyanates Catalysed by Aluminium Heteroscorpionate Complexes
Castro-Osma, José A.,Earlam, Amy,Lara-Sánchez, Agustín,Otero, Antonio,North, Michael
, p. 2100 - 2108 (2016/07/07)
The combination of an aluminium(heteroscorpionate) complex and tetrabutylammonium bromide acts as a highly efficient catalyst system for the synthesis of oxazolidinones from epoxides and isocyanates. Twenty two complexes were tested derived from a range o
