cas 86217-38-1, (S)-(+)-4-Phenyl-2-oxazolidinone

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Versatile Cp*Co(III)(LX) Catalyst System for Selective Intramolecular C-H Amidation Reactions
Herein, we report the development of a tailored cobalt catalyst system of Cp*Co(III)(LX) toward intramolecular C-H nitrene insertion of azidoformates to afford cyclic carbamates. The cobalt complexes were easy to prepare and bench-stable, thus offering a convenient reaction protocol. The catalytic reactivity was significantly improved by the electronic tuning of the bidentate LX ligands, and the observed regioselectivity was rationalized by the conformational analysis and DFT calculations of the transition states. The superior performance of the newly developed cobalt catalyst system could be broadly applied to both C(sp2)-H and C(sp3)-H carbamation reactions under mild conditions.
Chang, Sukbok,Jung, Hoimin,Kim, Dongwook,Lee, Jeonghyo,Lee, Jia,Park, Juhyeon
supporting information
p. 12324 - 12332
(2020/08/06)

One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: Theoretical evidence for an asynchronous concerted pathway
The one-pot reaction of chlorosulfonyl isocyanate (CSI) with epoxides having phenyl, benzyl and fused cyclic alkyl groups in different solvents under mild reaction conditions without additives and catalysts was studied. Oxazolidinones and five-membered cyclic carbonates were obtained in ratios close to 1:1 in the cyclization reactions. The best yields of these compounds were obtained in dichloromethane (DCM). Together with 16 known compounds, two novel oxazolidinone derivatives and two novel cyclic carbonates were synthesized with an efficient and straightforward method. Compared to the existing methods, the synthetic approach presented here provides the following distinct advantageous: being a one-pot reaction with metal-free reagent, having shorter reaction times, good yields and a very simple purification method. Moreover, using the density functional theory (DFT) method at the M06-2X/6-31+G(d,p) level of theory the mechanism of the cycloaddition reactions has been elucidated. The further investigation of the potential energy surfaces associated with two possible channels leading to oxazolidinones and five-membered cyclic carbonates disclosed that the cycloaddition reaction proceeds via an asynchronous concerted mechanism in gas phase and in DCM.
Demir, Esra,Sari, Ozlem,?etinkaya, Yasin,Atmaca, Ufuk,Erdem, Safiye Sa?,?elik, Murat
p. 1805 - 1819
(2020/11/07)

Tuning Triplet Energy Transfer of Hydroxamates as the Nitrene Precursor for Intramolecular C(sp3)-H Amidation
Reported herein is the design of a photosensitization strategy to generate triplet nitrenes and its applicability for the intramolecular C-H amidation reactions. Substrate optimization by tuning physical organic parameters according to the proposed energy transfer pathway led us to identify hydroxamates as a convenient nitrene precursor. While more classical nitrene sources, representatively organic azides, were ineffective under the current photosensitization conditions, hydroxamates, which are readily available from alcohols or carboxylic acids, are highly efficient in accessing synthetically valuable 2-oxazolidinones and γ-lactams by visible light. Mechanism studies supported our working hypothesis that the energy transfer path is mainly operative.
Chang, Sukbok,Jung, Hoimin,Keum, Hyeyun,Kweon, Jeonguk
supporting information
p. 5811 - 5818
(2020/04/10)

Synthesis of Chiral 5-Aryl-2-oxazolidinones via Halohydrin Dehalogenase-Catalyzed Enantio- and Regioselective Ring-Opening of Styrene Oxides
An efficient biocatalytic approach for enantio- and regioselective ring-opening of styrene oxides with cyanate was developed by using the halohydrin dehalogenase HheC from Agrobacterium radiobacter AD1, generating the corresponding chiral 5-aryl-2-oxazoli
Wan, Nanwei,Zhou, Xiaoying,Ma, Ran,Tian, Jiawei,Wang, Huihui,Cui, Baodong,Han, Wenyong,Chen, Yongzheng
supporting information
p. 1201 - 1207
(2020/02/05)

Cycloaddition of Aziridine with CO2/CS2 Catalyzed by Amidato Divalent Lanthanide Complexes
This is the first time that the amidato lanthanide amides ({LnLn[N(SiMe3)2]THF}2 (n = 1, Ln = Eu (1); n = 2, Ln = Eu (3), Yb (4); HL1 = tBuC6H4CONHC6H3(iPr)2; HL2 = C6H5CONHC6H3(iPr)2) and {L3Eu[N(SiMe3)2]THF}{L32Eu(THF)2} (2) (HL3 = ClC6H4CONHC6H3(iPr)2)) were applied in the cycloaddition reactions of aziridines with carbon dioxide (CO2) or carbon disulfide (CS2) under mild conditions. The corresponding oxazolidinones and thiazolidine-2-thiones were obtained in good to excellent yields with good functional group tolerance.
Xie, Yueqin,Lu, Chengrong,Zhao, Bei,Wang, Qianyu,Yao, Yingming
(2019/02/14)

Synthesis method and application of chiral 2-carbonyl oxazoline
The invention discloses a synthesis method of a chiral compound with a structural formula. According to the synthesis method, 50 mol% zinc chloride is used as a catalyst, 20.0 mmol of dicyandiamide and 10.5335 g of D-phenylglycinol are added, 50 mL of chlorobenzene is taken as a solvent, after a reflux reaction is carried out for 3 days, column chromatography isolation is conducted, petroleum ether/dichloromethane (1/9) is utilized for elution, collected second component points are naturally volatilized, and then monocrystal(R)-4-phenyloxazoline-2-ketone is obtained. According to application of the chiral compound crystal (I), a good catalysis effect is shown in a Henry reaction of ethyl pyruvate and nitromethane, and the conversion rate of the ethyl pyruvate and nitromethane reaches 95%.
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Paragraph 0007-0009

(2019/10/23)

Regioselective Ring-Opening of Styrene Oxide Derivatives Using Halohydrin Dehalogenase for Synthesis of 4-Aryloxazolidinones
A biocatalytic approach towards a range of 4-aryloxazolidinones is developed using a halohydrin dehalogenase from Ilumatobacter coccineus (HheG) as biocatalyst. The method is based on the HheG-catalyzed α-position regioselective ring-opening of styrene oxide derivatives with cyanate as a nucleophile, producing the corresponding 4-aryloxazolidinones in moderate to good yields. Synthesis of enantiopure 4-aryloxazolidinones is also achievable using chiral epoxide materials. (Figure presented.).
Wan, Nanwei,Tian, Jiawei,Zhou, Xiaoying,Wang, Huihui,Cui, Baodong,Han, Wenyong,Chen, Yongzheng
supporting information
p. 4651 - 4655
(2019/08/27)

Method of biocatalytically synthesizing 4-substituted oxazolidinone compound
The invention discloses a biocatalytic technology of synthesizing a 4-substituted oxazolidinone compound by carrying out a reaction on a halohydrin dehalogenase catalyzed epoxy compound and cyanate. The reaction takes the epoxy compound as a primer, cyanate as a nucleophilic ring opening reagent and halohydrin dehalogenase which is originated from an Ilumatobacter coccineus strain and has high alpha-offensive ring opening area selectivity as a biocatalyst. The reaction is carried out in a water phase and is mild in reaction condition. The invention is the biocatalytic method of catalyzing theepoxy compound to synthesize the 4-substituted oxazolidinone compound by using the halohydrin dehalogenase for the first time. The method has a wide application prospect in design of an oxazolidinonedrug and green manufacturing aspect thereof.
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Paragraph 0023; 0024; 0025; 0026

(2019/04/27)

Oxazoline metal compound, preparation method thereof and application of oxazoline metal compound as catalyst
The invention provides an oxazoline metal compound which has a structure shown as a formula (I), wherein n is 2 or 3, R1 is -OCH3 or -N(CH3)2, R2 is one of an alkyl group and a phenyl group, and M isMg or Zn. The oxazoline metal compound provided by the invention has high-activity silazane-based metal center; compared with a catalyst with a zinc alkyl or aluminum alkyl center in the prior art, the oxazoline metal compound provided by the invention has very high activity when catalyzing lactide or caprolactone to perform ring-opening polymerization, can realize monomer polymerization at room temperature, has equivalent selectivity to racemic lactide and improves the regularity of the microscopic chain structure of a polymerization product. Shown by experimental results, for polylactic acidprepared with the method, the conversion rate can reach 98 percent, the stereoscopic regularity (Pm) of the obtained polylactic acid can reach 0.53, and the conversion rate of polycaprolactone can reach 99 percent.
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Paragraph 0137-0140

(2018/12/14)

Directed β C-H Amination of Alcohols via Radical Relay Chaperones
A radical-mediated strategy for β C-H amination of alcohols has been developed. This approach employs a radical relay chaperone, which serves as a traceless director that facilitates selective C-H functionalization via 1,5-hydrogen atom transfer (HAT) and enables net incorporation of ammonia at the β carbon of alcohols. The chaperones presented herein enable direct access to imidate radicals, allowing their first use for H atom abstraction. A streamlined protocol enables rapid conversion of alcohols to their β-amino analogs (via in situ conversion of alcohols to imidates, directed C-H amination, and hydrolysis to NH2). Mechanistic experiments indicate HAT is rate-limiting, whereas intramolecular amination is product- and stereo-determining.
Wappes, Ethan A.,Nakafuku, Kohki M.,Nagib, David A.
supporting information
p. 10204 - 10207
(2017/08/10)

Synthesis of oxazolidinones: Rhodium-catalyzed C-H amination of: N -mesyloxycarbamates
N-Mesyloxycarbamates undergo intramolecular C-H amination reactions to afford oxazolidinones in good to excellent yields in the presence of rhodium(ii) carboxylate catalysts. The reaction is performed under green conditions and potassium carbonate is used, forming biodegradable potassium mesylate as a reaction by-product. This method enables the production of electron-rich, electron-deficient, aromatic and heteroaromatic oxazolidinones in good to excellent yields. Conformationally restricted cyclic secondary N-mesyloxycarbamates furnish cis-oxazolidinones in high yields and selectivity; DFT calculations are provided to account for the observed selectivity. trans-Oxazolidinones were prepared from acyclic secondary N-mesyloxycarbamates using Rh2(oct)4. The selectivity was reverted with a cytoxazone N-mesyloxycarbamate precursor using large chiral rhodium(ii) carboxylate complexes, affording the corresponding cis-oxazolidinone. This orthogonal selectivity was used to achieve the formal synthesis of (-)-cytoxazone.
Lebel, Hélène,Mamani Laparra, Laura,Khalifa, Maroua,Trudel, Carl,Audubert, Clément,Szponarski, Mathieu,Dicaire Leduc, Cédric,Azek, Emna,Ernzerhof, Matthias
supporting information
p. 4144 - 4158
(2017/07/10)

Catalyst-Controlled Nitrene Transfer by Tuning Metal:Ligand Ratios: Insight into the Mechanisms of Chemoselectivity
Catalyst-controlled, selective nitrene transfer is often challenging when both C-H and C - C bonds are present in a substrate. Interestingly, a simple change in the Ag(I):L ratio (L = bidentate N,N-donor ligand) enables tunable, chemoselective nitrene transfer that favors either C - C bond aziridination using an 1:1 Ag:L ratio (AgLOTf) or insertion into a C-H bond when the Ag:L ratio in the catalyst is 1:2 (AgL2OTf). In this paper, mechanistic studies, coupled with kinetic profiling of the entire reaction course, are employed to examine the reasons for this unusual behavior. Steady-state kinetics were found to be similar for both AgLOTf and AgL2OTf; both complexes yield electronically similar reactive intermediates that engage in nitrene transfer involving formation of a short-lived radical intermediate and barrierless radical recombination. Taken together, experimental and computational studies point to two effects that control tunable chemoselectivity: suppression of aziridination as the steric congestion around the silver center is increased in AgL2OTf and a decrease in the rate of C-H insertion with AgLOTf in comparison to AgL2OTf. The observation that the sterics of Ag catalysts can be varied, with minor effects on the electronic features of the putative nitrene, has important implications for the development of other silver catalysts that enable tunable, site-selective C-H bond aminations.
Weatherly, Cale,Alderson, Juliet M.,Berry, John F.,Hein, Jason E.,Schomaker, Jennifer M.
supporting information
p. 1649 - 1661
(2017/04/28)

Iron-Catalyzed Synthesis of Five-Membered Cyclic Carbonates from Vicinal Diols: Urea as Sustainable Carbonylation Agent
A new iron-catalyzed synthesis of cyclic carbonates from the corresponding vicinal diols and urea is described. This straightforward transformation allows for the preparation of a variety of five-membered carbonates by employing an inexpensive and environmentally benign iron salt as the catalyst. The use of readily available feedstocks such as urea and polyols makes this a sustainable process. As ammonia is formed as the only stoichiometric byproduct, this process can also be characterized by its high atom economy.
Pe?a-López, Miguel,Neumann, Helfried,Beller, Matthias
supporting information
p. 3721 - 3727
(2016/08/16)

Converting urea into high value-added 2-oxazolidinones under solvent-free conditions
Zn-modified mesoporous Mg-Al nanoplates oxides were prepared by co-precipitation and further characterized and used in the synthesis of 2-oxazolidinones from urea and epoxides under solvent-free conditions. The characterization results suggested that Zn1.1Mg2.0AlO4.6, which featured more accessible active medium basic sites, were favorable for obtaining superior catalytic activity. This synthetic process is mild, convenient, simple and gives good yields up to 80%.
Wang, Peixue,Li, Qinghe,Liu, Shimin,Deng, Youquan
p. 94382 - 94386
(2016/10/21)

Computer-assisted design, synthesis, binding and cytotoxicity assessments of new 1-(4-(aryl(methyl)amino)butyl)-heterocyclic sigma 1 ligands
In this work we applied a blend of computational and synthetic techniques with the aim to design, synthesize, and characterize new σ1 receptor (σ1R) ligands. Starting from the structure of previously reported, high-affinity benzoxazolone-based σ1 ligands, the three-dimensional homology model of the σ1R was exploited for retrieving the molecular determinants to fulfill the optimal pharmacophore requirements. Accordingly, the benzoxazolone moiety was replaced by other heterocyclic scaffolds, the relevant conformational space in the σ1R binding cavity was explored, and the effect on σ1R binding affinity was ultimately assessed. Next, the compounds designed in silico were synthesized, and their affinity and selectivity toward σ1and σ2receptors were tested. Finally, a representative series of best σ1R binders were assayed for cytotoxic activity on the SH-SY5Y human neuroblastoma cell line. Specifically, the new 4-phenyloxazolidin-2-one derivatives 2b (i.e., (R)-2b and (S)-2b) emerged as potential leads for further development as σ1R agents, as they were found endowed with the highest σ1R affinity (Kiσ1 values in the range 0.95–9.3?nM), and showed minimal cytotoxic levels exhibited in the selected, cell-based test, in line with a σ1R agonist behavior.
Zampieri, Daniele,Vio, Luciano,Fermeglia, Maurizio,Pricl, Sabrina,Wünsch, Bernhard,Schepmann, Dirk,Romano, Maurizio,Mamolo, Maria Grazia,Laurini, Erik
p. 712 - 726
(2016/07/06)

(Enantio)selective Hydrogen Autotransfer: Ruthenium-Catalyzed Synthesis of Oxazolidin-2-ones from Urea and Diols
A novel strategy for the synthesis of oxazolidin-2-ones from vicinal diols and urea is described. In this heterocycle synthesis, two different C?O and C?N bonds are sequentially formed in a domino process consisting of nucleophilic substitution and alcohol amination. The use of readily available starting materials and the good atom economy render this process environmentally benign. While this transformation is already highly chemo- and regioselective, we also developed the first asymmetric version of this method using (R)-(+)-MeO-BIPHEP as the chiral ligand.
Pe?a-López, Miguel,Neumann, Helfried,Beller, Matthias
supporting information
p. 7826 - 7830
(2016/07/07)

Enzymatic C(sp3)-H amination: P450-catalyzed conversion of carbonazidates into oxazolidinones
Cytochrome P450 enzymes can effectively promote the activation and cyclization of carbonazidate substrates to yield oxazolidinones via an intramolecular nitrene C-H insertion reaction. Investigation of the substrate scope shows that while benzylic/allylic C-H bonds are most readily aminated by these biocatalysts, stronger, secondary C-H bonds are also accessible to functionalization. Leveraging this "non-native" reactivity and assisted by fingerprint-based predictions, improved active-site variants of the bacterial P450 CYP102A1 could be identified to mediate the aminofunctionalization of two terpene natural products with high regio- and stereoselectivity. Mechanistic studies and KIE experiments show that the C-H activation step in these reactions is rate-limiting and proceeds in a stepwise manner, namely, via hydrogen atom abstraction followed by radical recombination. This study expands the reactivity scope of P450-based catalysts in the context of nitrene transfer transformations and provides first-time insights into the mechanism of P450-catalyzed C-H amination reactions.
Singh, Ritesh,Kolev, Joshua N.,Sutera, Philip A.,Fasan, Rudi
p. 1685 - 1691
(2015/03/14)

Aluminium-Catalysed Oxazolidinone Synthesis and their Conversion into Functional Non-Symmetrical Ureas
An efficient and practical aluminium-catalysed approach towards a range of functional oxazolidinones is reported. The method is based on cheap and readily available starting materials including terminal and internal (bicyclic) epoxides and phenyl carbamate. The oxazolidinones serve as highly useful synthons for the high yield preparation of non-symmetrical ureas by nucleophilic ring-opening affording the targeted urea compounds with excellent functional group diversity, high regioselectivity and isolated yields up to >99%.
Laserna, Victor,Guo, Wusheng,Kleij, Arjan W.
p. 2849 - 2854
(2015/09/28)

Efficient synthesis of 2-oxazolidinones from epoxides and carbamates catalyzed by amine-functionalized ionic liquids
A series of amine-functionalized ionic liquids were prepared and their catalytic performance was tested in the synthesis of 2-oxazolidinones from epoxides and carbamates. Under optimized reaction conditions, good to excellent yields of various 2-oxazolidinones were achieved with different epoxides and carbamates. Moreover, the amine-functionalized ionic liquid catalyst could be easily recovered and reused without significant loss in activity.
Shang, Jianpeng,Li, Zuopeng,Su, Caina,Guo, Yong,Deng, Youquan
p. 71765 - 71769
(2015/09/08)

Hydroxyamination of olefins using Br-n-(co2me)2
The hydroxyamination reagent Br-N-(CO2Me)2 underwent Markovnikov addition to various olefins in the presence of catalytic BF3·OEt2 and provides efficient access to aminoalcohols. The reaction provided the trans-1-bromo, 2-N-bis-carbamate adduct stereoisomer in all cases. The resulting adduct underwent cyclization to give an oxazolidinone, which could be readily hydrolyzed to an oxazolidin-2-one or an amino alcohol.
Kuszpit, Michael R.,Giletto, Matthew B.,Jones, Corey L.,Bethel, Travis K.,Tepe, Jetze J.
p. 1440 - 1445
(2015/02/19)

Efficient synthesis of 2-oxazolidinone from epoxides and carbamates with binary MgFe oxides as a magnetic solid base catalyst
Magnetic binary MgFe oxides were prepared by co-precipitation method, characterized and tested in the synthesis of 2-oxazolidinones from epoxides and carbamates. The catalytic results showed that the catalyst with Mg/Fe molar ratio of 1 and calcined at 400°C exhibited superior catalytic activity. The catalyst could be magnetically separated, recycled and reused for five runs without noticeable deactivation. Under the optimized conditions, various 2-oxazolidinones derivatives were successfully synthesized with good to excellent isolated yields.
Shang, Jianpeng,Liu, Shimin,Lu, Liujin,Ma, Xiangyuan,He, Yude,Deng, Youquan
p. 13 - 17
(2013/01/14)

Copper-catalyzed intramolecular C-H amination
The amino-functionalization of tertiary, secondary and benzylic C-H bonds of tethered carbamates and sulfamates by iodosobenzene is catalyzed by Cu I-diimine complexes in moderate to good yield. Employing homochiral imine-Cucatalysts affords oxazolidinones and oxathiazinanes with modest enantioselectivity.
Barman, Dipti N.,Nicholas, Kenneth M.
p. 908 - 911
(2011/04/26)

Naturally occurring α-amino acid: a simple and inexpensive catalyst for the selective synthesis of 5-aryl-2-oxazolidinones from CO2 and aziridines under solvent-free conditions
Naturally occurring α-amino acid successfully catalyzed cycloaddition of aziridine with carbon dioxide to afford 5-aryl-2-oxazolisinones under mild conditions without the need of any additives. The scope of this reaction is very general, providing the corresponding products in good yields and excellent regioselectivity (87:13-100:0) regardless of the α-amino acid examined and a wide variety of N-substituted aziridines employed. Two possible reaction pathways for the reaction were also discussed.
Jiang, Huan-Feng,Ye, Jin-Wu,Qi, Chao-Rong,Huang, Liang-Bin
experimental part
p. 928 - 932
(2010/05/18)

Catalyst-free process for the synthesis of 5-aryl-2-oxazolidinones via cycloaddition reaction of aziridines and carbon dioxide
A simple approach for facile synthesis of 5-aryl-2-oxazolidinones in excellent regioselectivity from aziridines under compressed CO2 conditions was developed in the absence of any catalyst and organic solvent. The reaction outcome was found to be tuned by subtly adjusting CO2 pressure. The adduct formed in situ of aziridine and CO2 is assumed to act as a catalyst in this reaction, which was also studied by means of in situ FT-IR technique.
Dou, Xiao-Yong,He, Liang-Nian,Yang, Zhen-Zhen,Wang, Jing-Lun
supporting information; experimental part
p. 2159 - 2163
(2010/10/21)

Environmentally benign chemical fixation of CO2 catalyzed by the functionalized ion-exchange resins
Basic ion-exchange resins, one kind of polystyryl-supported tertiary amine, were demonstrated to be highly efficient and recyclable catalysts for the fixation of carbon dioxide with aziridines under mild conditions, leading to the formation of 5-aryl-2-oxazolidinone with excellent regio-selectivities. Notably, neither solvents nor any additives were required, and the catalyst could be recovered by simple filtration and directly reused at least five times without significant loss of catalytic activity and selectivity. The present protocol has been applied to reactions of epoxides/propargyl amines with CO 2/CS2. This solvent-free process thus represents environmentally friendly catalytic conversion of CO2 into value-added chemicals and may have potential in various continuous flow reactors in industry.
Liu, Anhua,He, Liangnian,Peng, Shiyong,Pan, Zhongda,Wang, Jinglun,Gao, Jian
experimental part
p. 1578 - 1585
(2010/11/04)

Polystyrene-supported amino acids as efficient catalyst for chemical fixation of carbon dioxide
Four new polystyrene-supported amino acids have been synthesized and applied to the chemical fixation of carbon dioxide for the first time. Two series of experiments with polystyrene-supported threonine (PS-Thr) and polystyrene-supported tyrosine (PS-Tyr) as catalyst, respectively, were conducted to study the effect of the reaction conditions on the carboxylation of propylene oxide/carbon dioxide. There was no considerable decrease in the yield of propylene carbonate after the polystyrene-supported amino acids were used five times, indicating that these catalysts are very stable. It was demonstrated that these catalysts were very efficient in the carboxylation of various epoxides and aziridines with carbon dioxide under mild conditions without any solvents. The mechanism for this carboxylation is also discussed.
Qi, Chaorong,Ye, Jinwu,Zeng, Wei,Jiang, Huanfeng
supporting information; experimental part
p. 1925 - 1933
(2010/11/04)

Zirconyl chloride: an efficient recyclable catalyst for synthesis of 5-aryl-2-oxazolidinones from aziridines and CO2 under solvent-free conditions
Zirconyl chloride was found to be an efficient catalyst for the cycloaddition reaction of aziridines with CO2, thus leading to the preferential formation of 5-aryl-2-oxazolidinones under solvent-free conditions. The methodology could be extended to various substituted aziridines with high conversion and chemo-, regio-, and stereoselectivity. Furthermore, the catalyst could be reused over five times without significant loss in activity. Interestingly, the recovered catalyst showed higher activity in comparison with the fresh catalyst, presumably due to its morphological variation. The use of this cheap and moisture stable catalyst make this protocol practical, environmentally benign, and economically attractive.
Wu, Ying,He, Liang-Nian,Du, Ya,Wang, Jin-Quan,Miao, Cheng-Xia,Li, Wei
experimental part
p. 6204 - 6210
(2011/03/21)

N-tosyloxycarbamates as reagents in rhodium-catalyzed C-H amination reactions
Metal nitrenes for use in C-H insertion reactions were obtained from N-tosyloxycarbamates in the presence of an inorganic base and a rhodium(II) dimer complex catalyst. The C-H amination reaction proceeds smoothly, and the potassium tosylate that forms as a byproduct is easily removed by filtration or an aqueous workup. This new methodology allows the amination of ethereal, benzylic, tertiary, secondary, and even primary C-H bonds. The intramolecular reaction provides an interesting route to various substituted oxazolidinones, whereas the intermolecular reaction gives trichloroethoxycarbonyl-protected amines that can be isolated with moderate to excellent yields and that cleave easily to produce the corresponding free amine. The development, scope, and limitations of the reactions are discussed herein. Isotopic effects and the electronic nature of the transition state are used to discuss the mechanism of the reaction.
Huard, Kim,Lebel, Helene
scheme or table
p. 6222 - 6230
(2009/05/27)

Quaternary ammonium bromide functionalized polyethylene glycol: A highly efficient and recyclable catalyst for selective synthesis of 5-aryl-2-oxazolidinones from carbon dioxide and aziridines under solvent-free conditions
(Chemical Equation Presented) A quaternary ammonium bromide covalently bound to polyethylene glycol (PEG, MW = 6000), i.e., PEG6000- (NBu3Br)2, was found to be an efficient and recyclable catalyst for the cycloaddition reaction of aziridines to CO2 under mild conditions without utilization of additional organic solvents or cocatalysts. As a result, 5-aryl-2-oxazolidinone was obtained in high yield with excellent regioselectivity. The catalyst worked well for a wide variety of 1-alkyl-2-arylaziridines. Besides, the catalyst could be recovered by centrifugation and reused without significant loss of catalytic activity and selectivity.
Du, Ya,Wu, Ying,Liu, An-Hua,He, Liang-Nian
p. 4709 - 4712
(2008/09/21)

An excellent procedure for the synthesis of oxazolidin-2-ones
Synthesis of oxazolidin-2-ones derivatives was carried out starting from urea and ethanolamine reagents using microwave irradiation in a chemical paste medium. Georg Thieme Verlag Stuttgart.
Bratulescu, George
p. 3111 - 3112
(2008/09/16)

Kinetic resolution of 2-oxazolidinones via catalytic, enantioselective N-acylation
Kinetic resolution of racemic 2-oxazolidinones via catalytic, enantioselective N-acylation has been achieved for the first time and with outstanding selectivities. Copyright
Birman, Vladimir B.,Jiang, Hui,Li, Ximin,Guo, Lei,Uffman, Eric W.
p. 6536 - 6537
(2007/10/03)

N-tosyloxycarbamates as a source of metal nitrenes: Rhodium-catalyzed C-H insertion and aziridination reactions
The rhodium-catalyzed decomposition of N-tosyloxycarbamates to generate metal nitrenes which undergo intramolecular C-H insertion or aziridination reaction is described. Aliphatic N-tosyloxycarbamates produce oxazolidinones with high yields and stereospecificity through insertion in benzylic, tertiary, and secondary C-H bonds. Intramolecular aziridination occurs with allylic N-tosyloxycarbamates to produce aziridines as single diastereomers. The reaction proceeds at room temperature using a rhodium catalyst and an excess of potassium carbonate and does not require the use of strong oxidant, such as hypervalent iodine reagents. A rhodium nitrene species is presumably involved, as both reactions are stereospecific. Copyright
Lebel, Helene,Huard, Kim,Lectard, Sylvain
p. 14198 - 14199
(2007/10/03)

Chemical fixation of carbon dioxide co-catalyzed by a combination of Schiff bases or phenols and organic bases
Binaphthyldiamino, ethyldiamino and cyclohexyldiamino Schiff bases can catalyze the reaction of epoxides with carbon dioxide in the presence of catalytic amounts of various organic bases to give the corresponding cyclic carbonates in high yields. The simplest binaphthyldiamino Schiff base, derived from the reaction of binaphthyldiamine with salicylaldehyde, gave the highest yield of cyclic carbonate. This catalytic system can be further simplified by use of a phenol instead of the Schiff base to give the corresponding cyclic carbonates in high yields as well. Mechanistic insights were obtained based on a deuterium labeling experiment, The reaction of aziridines with CO2 and epoxide with CS2 were also examined under the same reaction conditions. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Shen, Yu-Mei,Duan, Wei-Liang,Shi, Min
p. 3080 - 3089
(2007/10/03)

A silver-catalyzed intramolecular amidation of saturated C-H bonds
Opportunities with silver: A dinuclear silver(I) compound was found to efficiently catalyze the intramolecular amidation of saturated C-H bonds of carbamates and sulfamates (see scheme). This highly regioselective, stereospecific reaction offers a practical method for the construction of cyclic nitrogen-containing organic molecules.
Cui, Yong,He, Chuan
p. 4210 - 4212
(2007/10/03)

Highly Enantioselective Synthesis of 1,2-Amino Alcohol Derivatives via Proline-Catalyzed Mannich Reaction
Here we report a new catalytic asymmetric synthesis of oxazolidin-2-ones 4 and Cbz-protected 1,2-amino alcohols 5. Our sequence is based on the chemistry of previously unknown 5-acyloxy-oxazolidin-2-ones, which are obtained via proline-catalyzed direct asymmetric three-component Mannich reaction and Baeyer-Villiger oxidation.
Pojarliev, Peter,Biller, William T.,Martin, Harry J.,List, Benjamin
p. 1903 - 1905
(2007/10/03)

Highly efficient chemical fixations of carbon dioxide and carbon disulfide by cycloaddition to aziridine under atmospheric pressure
Cycloaddition of aziridine with carbon dioxide was successfully catalyzed by alkali metal halide or tetraalkylammonium halide to give the corresponding 5-membered cyclic urethane, 1,3-oxazolidin-2-one, selectively. The reaction can be performed at ambient
Sudo, Atsushi,Morioka, Yosuke,Koizumi, Eri,Sanda, Fumio,Endo, Takeshi
p. 7889 - 7891
(2007/10/03)

Highly efficient CuI-catalyzed coupling of aryl bromides with oxazolidinones using Buchwald's protocol: a short route to linezolid and toloxatone.
[reaction: see text] Coupling of a variety of substituted aryl bromides with oxazolidinones has been achieved using the Buchwald protocol for the amidation of aryl halides. This procedure is exemplified by the synthesis of two medicinally important molecules, linezolid and toloxatone.
Mallesham,Rajesh,Reddy, P Rajamohan,Srinivas,Trehan, Sanjay
p. 963 - 965
(2007/10/03)

Chemoselective debezylation of the N-1-phenylethyl group in 2-oxazolidinones by the anisole-methanesulfonic acid system
The chemoselective removal of N-1-phenylethyl group in 2-oxazolidinones by the anisole-methanesulfonic acid system was investigated. Optically active 4,5-cis- and 4,5-trans-diphenyl-2-oxazolidinones (1a-d) were easily synthesized from dl-stilbene oxides (trans- and cis-7a) using this debenzylation.
Sugiyama, Shigeo,Morishita, Kenji,Chiba, Mariko,Ishii, Keitaro
p. 637 - 648
(2007/10/03)

From vicinal azido alcohols to Boc-amino alcohols or oxazolidinones, with trimethylphosphine and Boc2O or CO2
A practical solution to the problem of converting directly 1,2-azido alcohols to Boc-amino alcohols, without recourse to catalytic hydrogenation, involves the use of Me3P/Boc2O in THF (or CH2Cl2) and aqueous NaOH at rt (90-98% yields). The same azido alcohols can be converted in one-pot to the corresponding oxazolidinones with Boc2O/DMAP/Me3P or even better with CO2 and Me3P under basic catalysis (91-96% yields).
Ariza, Xavier,Pineda, Oriol,Urpí, Fèlix,Vilarrasa, Jaume
p. 4995 - 4999
(2007/10/03)

A Rh-catalyzed C-H insertion reaction for the oxidative conversion of carbamates to oxazolidinones
Selective intramolecular alkane oxidations: an RhII carboxylate catalyzed C-H amination reaction facilitates the preparation of 1,2-amino alcohols from primary carbamates. The reaction is stereospecific, providing access to chiral α-branched amines from optically pure starting with no loss in enantiomeric excess (see scheme).
Espino, Christine G.,Du Bois
p. 598 - 600
(2007/10/03)

Electrosynthesis of cyclic carbamates from aziridines and carbon dioxide
A new and selective synthesis of five-membered ring cyclic carbamates involving nickel-catalyzed CO2 incorporation into aziridines under mild electrochemical conditions was carried out in good yields.
Tascedda, Patricia,Dunach, Elisabet
p. 449 - 450
(2007/10/03)

One-pot conversion of alkenes into oxazolines and oxazolidin-2-ones promoted by diphenyl diselenide
Oxazolines or oxazolidin-Zones are produced from the reaction of diphenyl diselenide, ammonium persulfate and trifluoromethanesulfonic acid with alkenes in the presence of MeCN/H2O, NH2CN/H2O or NH2CO2Et.
Tiecco, Marcello,Testaferri, Lorenzo,Marini, Francesca,Temperini, Andrea,Bagnoli, Luana,Santi, Claudio
p. 4131 - 4140
(2007/10/03)

1H NMR Spectroscopic Studies on the Reactions of Haloalkylamines with Bicarbonate Ions: Formation of N-Carbamates and 2-Oxazolidones in Cell Culture Media and Blood Plasma
1H NMR spectroscopic methods have been applied to compare the in vitro reactivity of the renal papillary nephrotoxin 2-bromoethanamine (BEA) with those of selected halide-substituted nephrotoxic analogues, 2-chloroethanamine (CEA), 2-fluoroethanamine (FEA), and 1-phenyl-2-iodoethanamine (PIEA). The primary 1H NMR-detectable transformation during a 24 h incubation of confluent Madin Darby canine kidney (MDCK) cells with BEA, CEA, and FEA (at concentrations up to the IC50 determined by neutral red uptake) was the appearance in cell culture media of 2-oxazolidone (OX). Additional novel signals assigned as FEA carbamate (N-carbanoyl-2-fluoroethanamine) were observed in media collected following incubation of cells with FEA. We propose that N-carbamate intermediates are formed from the spontaneous reaction of these haloalkylamines with HCO3--buffered growth media and that OX is formed from the carbamate via elimination of the hydrogen halide. Further 1H NMR experiments, conducted for up to 8 h at 25 deg C on 5 mM solutions of BEA, CEA, and FEA in (2)H2O containing a 20-fold excess of HCO3- at pH 7.6, demonstrated a time-dependent decrease in the concentration of the free haloalkylamines accompanied by the production of N-carbamate intermediates and OX. Under these pseudo-first-order reaction conditions, the formation of OX from BEA was complete within approximately 6 h. In similar reaction conditions OX formation from CEA (24 h after initiation) had reached 54 percent of its final equilibrium concentration. Equivalent experiments demonstrated that PIEA was almost completely converted to 4-phenyl-2-oxazolidinone (PHOX) within 2 h. These observations reveal the strong disposition of this series of haloalkylamines toward reaction with HCO3- and indicate that the compounds in this family may exist only transiently as free amines in vivo, where there will virtually always be excess HCO3-. The physiological relevance of the in vitro findings is further indicated by the NMR-detectable conversion of BEA to OX and also an alkylating aziridine (AZ) moiety in rat plasma containing BEA. The ability to form carbamoylated species and OX (or PHOX) may mediate the toxicity of this series of haloalkylamines and hence is potentially of considerable significance.
Anthony, Maria L.,Holmes, Elaine,McDowell, Peter C. R.,Gray, Tim J. B.,Blackmore, Melanie,Nicholson, Jeremy K.
p. 1046 - 1053
(2007/10/03)

Practical Preparation of Chiral 4-Substituted 2-Oxazolidinones
A versatile and practical route to both enantiomers of a wide variety of 4-substituted 2-oxazolidinones from the parent heterocycle is provided by regioselective substitutions via 4-methoxy derivative followed by chromatographic separation of the diastereomers derived from N-2-exo-methoxy-1-apocamphanecarbonylation.
Ishizuka, Tadao,Kimura, Koreichi,Ishibuchi, Seigo,Kunieda, Takehisa
p. 991 - 994
(2007/10/02)

Oxazolidinone penetration enhancing compounds
Compositions for carrying physiologically active agents through body membranes having the structural formula I: STR1 where: R=H, Alkyl group containing from 1-18 carbon atoms, cycloalkyl, aryl, aralkyl, alkoxy, hydroxyalkyl, alkoyloxyalkyl, acyloxyalkyl and alkoxyalkyl; X=O and NR1, where R1 is selected from H, alkyl, aralkyl acyl group containing from 1-18 carbon atoms, cycloalkyl, hydroxyalkyl, alkoyloxyalkyl acyloxyalkyl and alkoxyalkyl; Y=O and NR2, where R2 is selected from H, alkyl, aralkyl, cycloalkyl, acyl group containing from 1-18 carbon atoms, hydroxyalkyl, alkoyloxyalkyl, acyloxyalkyl and alkoxyalkyl; m=2-4; and n=0-4, are disclosed.
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(2008/06/13)

Carbon dioxide Fixation forming Oxazolidone coupled with a Thio/Fe4S4 Cluster Redox System
Carbon dioxide fixation reactions with ethanolamines to form oxazolidone derivatives have been investigated using 4Fe-Σ ferredoxin analogues as the electron mediator.
Kodaka, Masato,Tomohiro, Takenori,Lee, Ah Lek,Okuno, Hiroaki(Yohmei)
p. 1479 - 1481
(2007/10/02)

Aminotellurinylation of Olefins and Its Utilization for Synthesis of 2-Oxazolidinones
Benzenetellurinyl acetate or trifluoroacetate in combination with ethyl carbamate effected regio- and stereoselective aminotellurinylation of olefins in the presence of boron trifluoride etherate in chloroform under reflux to give ethyl carbamates in high yields.Benzenetellurinyl trifluoromethanesulfonate similarly did it even at the lower temperature of refluxing dichloromethane without Lewis acid.This reaction was successfully extended to cyclofunctionalization of olefinic carbamates into nitrogen heterocycles.Furthermore, when the aminotellurinylation was carried out in refluxing 1,2-dichloroethane, 2-oxazolidinone was obtained in a high yield.A mechanism of addition followed by intramolecular substitution in proposed on the basis of the stereochemistry of 2-oxazolidinone derivatives.
Hu, Nan Xing,Aso, Yoshio,Otsubo, Tetsuo,Ogura, Fumio
p. 4398 - 4404
(2007/10/02)

NEW SYNTHETIC REACTIONS USING ARENETELLURINIC ANHYDRIDES
New synthetic reactions utilizing arenetellurinic acid anhydrides are described.The anhydrides proved to be very useful reagents for the transformation of various functional groups.Furthermore they induced various intramolecular cyclofunctionalizations to yield many oxygen and nitrogen heterocycles.
Hu, Nan Xing,Aso, Yoshio,Otsubo, Tetsuo,Ogura, Fumio
p. 177 - 190
(2007/10/02)

Organotellurium-mediated Synthesis of Oxazolidin-2-ones from Alkenes
Phenyltellurinyl trifluoroacetate in combination with ethyl carbamate and boron trifluoride-diethyl ether reacted with alkenes in refluxed 1,2-dichloroethane, regio- and stereo-selectively giving oxazolidin-2-ones in high yields.
Hu, Nan X.,Aso, Yoshio,Otsubo, Tetsuo,Ogura, Fumio
p. 1447 - 1448
(2007/10/02)

RING ENLARGING DIPOLAR CYCLOADDITIONS OF CHLOROSULFONYLISOCYANATE TO EPOXIDES
Chlorosulfonyl isocyanate cycloadds to epoxides at -78 deg C to give 1,3-dioxolan-2-ones and/or 2-oxazolidones in moderate yields after aqueous work-up.
Lorincz, Tibor,Erden, Ihsan,Naeder, Reinhard,Meijere, Armin de
p. 123 - 130
(2007/10/02)