- Oxovanadium(v)-catalyzed amination of carbon dioxide under ambient pressure for the synthesis of ureas
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Carbon dioxide is regarded as a reliable C1 building block in organic synthesis because of the nontoxic, abundant, and economical characteristics of carbon dioxide. In this manuscript, a commercially available oxovanadium(v) compound was demonstrated to serve as an efficient catalyst for the catalytic amination of carbon dioxide under ambient pressure in the synthesis of ureas. The catalytic transformation of chiral amines into the corresponding chiral ureas without loss of chirality was also performed. Furthermore, a gram-scale catalytic urea synthesis under ambient pressure was successfully achieved to validate the scalability of this catalytic activation of carbon dioxide. This journal is
- Moriuchi, Toshiyuki,Sakuramoto, Takashi,Matsutani, Takanari,Kawai, Ryota,Donaka, Yosuke,Tobisu, Mamoru,Hirao, Toshikazu
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p. 27121 - 27125
(2021/08/24)
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- Development of a Polo-like Kinase-1 Polo-Box Domain Inhibitor as a Tumor Growth Suppressor in Mice Models
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Polo-like kinase-1 (Plk1) plays a key role in mitosis and has been identified as an attractive anticancer drug target. Plk1 consists of two drug-targeting sites, namely, N-terminal kinase domain (KD) and C-terminal polo-box domain (PBD). As KD-targeting inhibitors are associated with severe side effects, here we report on the pyrazole-based Plk1 PBD inhibitor, KBJK557, which showed a remarkable in vitro anticancer effect by inducing Plk1 delocalization, mitotic arrest, and apoptosis in HeLa cells. Further, in vivo optical imaging analysis and antitumorigenic activities in mouse xenograft models demonstrate that KBJK557 preferentially accumulates in cancer cells and selectively inhibits cancer cell proliferation. Pharmacokinetic profiles and partition coefficients suggest that KBJK557 was exposed in the blood and circulated through the organs with an intermediate level of clearance (t1/2, 7.73 h). The present investigation offers a strategy for specifically targeting cancer using a newly identified small-molecule inhibitor that targets the Plk1 PBD.
- Gunasekaran, Pethaiah,Yim, Min Su,Ahn, Mija,Soung, Nak-Kyun,Park, Jung-Eun,Kim, Jaehi,Bang, Geul,Shin, Sang Chul,Choi, Joonhyeok,Kim, Minkyoung,Kim, Hak Nam,Lee, Young-Ho,Chung, Young-Ho,Lee, Kyeong,Eunkyeong Kim, Eunice,Jeon, Young-Ho,Kim, Min Ju,Lee, Kyeong-Ryoon,Kim, Bo-Yeon,Lee, Kyung S.,Ryu, Eun Kyoung,Bang, Jeong Kyu
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p. 14905 - 14920
(2020/12/02)
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- Amine-Responsive Disassembly of AuI–CuI Double Salts for Oxidative Carbonylation
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A sensitive amine-responsive disassembly of self-assembled AuI-CuI double salts was observed and its utilization for the synergistic catalysis was enlightened. Investigation of the disassembly of [Au(NHC)2][CuI2] revealed the contribution of Cu-assisted ligand exchange of N-heterocyclic carbene (NHC) by amine in [Au(NHC)2]+ and the capacity of [CuI2]? on the oxidative step. By integrating the implicative information coded in the responsive behavior and inherent catalytic functions of d10 metal complexes, a catalyst for the oxidative carbonylation of amines was developed. The advantages of this method were clearly reflected on mild reaction conditions and the significantly expanded scope (51 examples); both primary and steric secondary amines can be employed as substrates. The cooperative reactivity from Au and Cu centers, as an indispensable prerequisite for the excellent catalytic performance, was validated in the synthesis of (un)symmetric ureas and carbamates.
- Cao, Yanwei,Yang, Jian-Gong,Deng, Yi,Wang, Shengchun,Liu, Qi,Shen, Chaoren,Lu, Wei,Che, Chi-Ming,Chen, Yong,He, Lin
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supporting information
p. 2080 - 2084
(2019/12/24)
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- Concise and Additive-Free Click Reactions between Amines and CF3SO3CF3
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Trifluoromethyl trifluoromethanesulfonate has proved to be an excellent reservoir of difluorophosgene and a promising click ligation for amines in the preparation of urea derivatives, heterocycles, and carbamoyl fluorides under metal- and additive-free conditions. The reactions are rapid, efficient, selective, and versatile, and can be performed in benign solvents, giving products in excellent yields with minimal efforts for purification. The characteristics of the reactions meet the requirements of a click reaction. The use of trifluoromethyl trifluoromethanesulfonate as a click reagent is advantageous over other “CO” sources (e.g., TsOCF3, PhCO2CF3, CsOCF3, AgOCF3, and triphosgene) because this reagent is readily accessible; easy to scale up; and highly reactive, even under metal- and additive-free conditions. It is anticipated that CF3SO3CF3 will be increasingly as important as SO2F2 as a click agent in future drug design and development.
- Song, Hai-Xia,Han, Zhou-Zhou,Zhang, Cheng-Pan
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supporting information
p. 10907 - 10912
(2019/08/02)
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- Base-Mediated Intramolecular Decarboxylative Synthesis of Alkylamines from Alkanoyloxycarbamates
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A general and effective method for the synthesis of alkylamine via intramolecular decarboxylation of alkanoyloxycarbamates is described. The alkanoyloxycarbamates are readily prepared with alkyl carboxylic acids and hydroxylamine. The reaction shows a broad range of substrates (primary and secondary alkyl) with functional tolerance, and the corresponding products were obtained in good yields under mild conditions.
- Li, Peihe,Ma, Nuannuan,Wang, Zheng,Dai, Qipu,Hu, Changwen
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p. 8233 - 8240
(2018/05/31)
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- Effective approach to ureas through organocatalyzed one-pot process
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An efficient approach to N, N′-unsymmetrically substituted ureas 9 has been developed through the ammonolysis process of N-Boc protected anilines 7 with amines prompted by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD). Moreover, a convenient protocol for the
- Wang, Mingliang,Han, Jilai,Si, Xiaojia,Hu, Yimin,Zhu, Jidong,Sun, Xun
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supporting information
p. 1614 - 1618
(2018/03/28)
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- Iron-catalyzed urea synthesis: Dehydrogenative coupling of methanol and amines
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Substituted ureas have numerous applications but their synthesis typically requires the use of highly toxic starting materials. Herein we describe the first base-metal catalyst for the selective synthesis of symmetric ureas via the dehydrogenative coupling of methanol with primary amines. Using a pincer supported iron catalyst, a range of ureas was generated with isolated yields of up to 80% (corresponding to a catalytic turnover of up to 160) and with H2 as the sole byproduct. Mechanistic studies indicate a stepwise pathway beginning with methanol dehydrogenation to give formaldehyde, which is trapped by amine to afford a formamide. The formamide is then dehydrogenated to produce a transient isocyanate, which reacts with another equivalent of amine to form a urea. These mechanistic insights enabled the development of an iron-catalyzed method for the synthesis of unsymmetric ureas from amides and amines.
- Lane, Elizabeth M.,Hazari, Nilay,Bernskoetter, Wesley H.
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p. 4003 - 4008
(2018/05/04)
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- Method for synthesizing benzothiazolone-based and 1,3-disubstituted urea-based derivatives through activation of CO2
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The present invention relates to a method for synthesizing benzothiazolone-based and 1,3-disubstituted urea-based derivatives through activation of CO2. According to the present invention, an inexpensive and easily-available sulfur-containing metal salt compound is first used as an activation catalyst for CO2, and a reaction raw material and CO2 are converted into a corresponding target compound at a low reaction temperature under a low CO2 pressure; and the method has high atomic economy, can reduce the generation of by-products, meets the standards of environmental friendliness and environmentally friendly chemistry, and is the effective way capable of completely utilizing CO2 as the renewable resource, developing new energy and achieving the beneficial cycle of carbon in nature.
- -
-
Paragraph 0062; 0063; 0064; 0068
(2018/09/12)
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- Ruthenium-Catalyzed Urea Synthesis by N-H Activation of Amines
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Activation of the N-H bond of amines by a ruthenium pincer complex operating via amine-amide metal-ligand cooperation is demonstrated. Catalytic formyl C-H activation of N,N-dimethylformamide (DMF) is observed in situ, which resulted in the formation of CO and dimethylamine. The scope of this new mode of bond activation is extended to the synthesis of urea derivatives from amines using DMF as a carbon monoxide (CO) surrogate. This catalytic protocol allows the synthesis of simple and functionalized urea derivatives with liberation of hydrogen, devoid of any stoichiometric activating reagents, and avoids the direct use of fatal CO. The catalytic carbonylation occurred at low temperature to provide the formamide; a formamide intermediate was isolated. The consecutive addition of different amines provided unsymmetrical urea compounds. The reactions are proposed to proceed via N-H activation of amines followed by CO insertion from DMF and with liberation of dihydrogen.
- Krishnakumar, Varadhan,Chatterjee, Basujit,Gunanathan, Chidambaram
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supporting information
p. 7278 - 7284
(2017/06/23)
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- Sulfated polyborate-catalyzed efficient and expeditious synthesis of (un)symmetrical ureas and benzimidazolones
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The excellent catalytic potential of sulfated polyborate is utilized in the synthesis of (un)symmetrical ureas and benzimidazolones by heating amines or substituted OPDA and urea or N-phenylureas under a solvent-free condition at 120 °C is described. The key advantages of the present protocol are phosgene-free, and other hazardous reagents or organic solvent free, high reaction rates and yields, simple workup procedure, and recyclability of the catalyst.
- Rekunge, Deelip S.,Khatri, Chetan K.,Chaturbhuj, Ganesh U.
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supporting information
p. 4304 - 4307
(2017/10/12)
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- Occurrence of urea-based soluble epoxide hydrolase inhibitors from the plants in the order Brassicales
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Recently, dibenzylurea-based potent soluble epoxide hydrolase (sEH) inhibitors were identified in Pentadiplandra brazzeana, a plant in the order Brassicales. In an effort to generalize the concept, we hypothesized that plants that produce benzyl glucosinolates and corresponding isothiocyanates also produce these dibenzylurea derivatives. Our overall aim here was to examine the occurrence of urea derivatives in Brassicales, hoping to find biologically active urea derivatives from plants. First, plants in the order Brassicales were analyzed for the presence of 1, 3-dibenzylurea (compound 1), showing that three additional plants in the order Brassicales produce the urea derivatives. Based on the hypothesis, three dibenzylurea derivatives with sEH inhibitory activity were isolated from maca (Lepidium meyenii) roots. Topical application of one of the identified compounds (compound 3, human sEH IC50= 222 nM) effectively reduced pain in rat inflammatory pain model, and this compound was bioavailable after oral administration in mice. The biosynthetic pathway of these urea derivatives was investigated using papaya (Carica papaya) seed as a model system. Finally, a small collection of plants from the Brassicales order was grown, collected, extracted and screened for sEH inhibitory activity. Results show that several plants of the Brassicales order could be potential sources of urea-based sEH inhibitors.
- Kitamura, Seiya,Morisseau, Christophe,Harris, Todd R.,Inceoglu, Bora,Hammock, Bruce D.
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- Ruthenium-Catalyzed Urea Synthesis Using Methanol as the C1 Source
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An unprecedented protocol for urea synthesis directly from methanol and amine was accomplished. The reaction is highly atom-economical, producing hydrogen as the sole byproduct. Commercially available ruthenium pincer complexes were used as catalysts. In addition, no additive, such as a base, oxidant, or hydrogen acceptor, was required. Furthermore, unsymmetrical urea derivatives were successfully obtained via a one-pot, two-step reaction.
- Kim, Seung Hyo,Hong, Soon Hyeok
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supporting information
p. 212 - 215
(2016/02/03)
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- Hydrogen bond organocatalysis of benzotriazole in transamidation of carboxamides with amines
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A new method of transamidation of carboxamides with amines catalyzed by benzotriazole has been developed.
- Nguyen, Thanh Binh,Ermolenko, Ludmila,Dau, Marie-Elise Tran Huu,Al-Mourabit, Ali
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p. 403 - 416
(2014/01/17)
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- Mesoporous niobium oxide spheres as an effective catalyst for the transamidation of primary amides with amines
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Mesoporous niobium oxide spheres (MNOS), conveniently prepared by a novel antisolvent precipitation approach, have been shown to be an effective catalyst for the transamidation of primary amides with amines. This novel transamidation can be efficiently carried out under solvent-free conditions and is applicable to a wide range of primary amides and amines to provide N-alkyl amides in good to excellent yields. The catalyst is highly stable and reusable. The application of this transamidation reaction has been demonstrated in the synthesis of antidepressant drug moclobemide and other druglike compounds.
- Ghosh, Subhash Chandra,Li, Cheng Chao,Zeng, Hua Chun,Ngiam, Joyce S. Y.,Seayad, Abdul M.,Chen, Anqi
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p. 475 - 484
(2014/05/20)
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- Trinuclear gold clusters supported by cyclic (alkyl)(amino)carbene ligands: Mimics for gold heterogeneous catalysts
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The synthesis of air- and moisture-stable trinuclear mixed-valence gold(I)/gold(0) clusters is described. They promote the catalytic carbonylation of amines under relatively mild conditions. The synthetic route leading to the trinuclear clusters involves a simple ligand exchange from the readily available μ3-oxo-[(Ph3PAu)3O]+ complex. This synthetic method paves the way for the preparation of a variety of mixed-valence gold(I)/gold(0) polynuclear clusters. Moreover, the well-defined nature of the complexes demonstrates that the catalytic process involves a rare example of a definite change of oxidation state of gold from Au0 2AuI to AuI3.
- Jin, Liqun,Weinberger, David S.,Melaimi, Mohand,Moore, Curtis E.,Rheingold, Arnold L.,Bertrand, Guy
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supporting information
p. 9059 - 9063
(2014/12/09)
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- Synthesis of ureas from titanium imido complexes using CO2 as a C-1 reagent at ambient temperature and pressure
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The coordinatively unsaturated 12-electron complex dichloro t-butylimido bispyridine titanium(iv) (2a) has been shown to react with CO2 to give N,N-bis-t-butyl urea. Two analogous sterically hindered coordinatively saturated 14-electron complexes dichloro t-butylimido trispyridine titanium(iv) (10a) and dichloro 2,6-(i-Pr)2phenylimido trispyridine titanium(iv) (10b) also gave their corresponding symmetrical ureas upon treatment with CO2. Further experiments support the intermediary of metallocycles formed from heterocumulene metathesis reactions. The unsymmetrical urea N-benzyl, N-t-butyl urea (11) was produced from treatment of 2,6-(i-Pr) 2phenylimido trispyridine titanium(iv) (10b) with CO2 and interception with BnNH2. Equimolar quantities of N,N- bistrimethylsilybenzylamine or N,N-bistrimethylsilyphenethylamine were shown to promote the reaction between t-butylimido bispyridine titanium(iv) (2a) and CO2 to give near quantitative yields of symmetrical urea. Other symmetrical ureas could be produced from TiCl4, amine and CO 2 in moderate to quantitative yields depending on the stoichiometry of amine present.
- Anderson, James C.,Moreno, Rafael Bou
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supporting information; experimental part
p. 1334 - 1338
(2012/04/10)
-
- Pyrimidine-2,4,6-trione derivatives and their inhibition of mutant SOD1-dependent protein aggregation. Toward a treatment for amyotrophic lateral sclerosis
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Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motor neurons, leading to muscle weakness, paralysis, and death, most often from respiratory failure. The only FDA-approved drug for the treatment of ALS, riluzole, only extends the median survival in patients by 2-3 months. There is an urgent need for novel therapeutic strategies for this devastating disease. Using a high-throughput screening assay targeting an ALS cultured cell model (PC12-G93A-YFP cell line), we previously identified three chemotypes that were neuroprotective. We present a further detailed analysis of one promising scaffold from that group, pyrimidine-2,4,6-triones (PYTs), characterizing a number of PYT analogues using SAR and ADME. The PYT compounds show good potency, superior ADME data, low toxicity, brain penetration, and excellent oral bioavailability. Compounds from this series show 100% efficacy in the protection assay with a good correlation in activity between the protection and protein aggregation assays. The modifications of the PYT scaffold presented here suggest that this chemical structure may be a novel drug candidate scaffold for use in clinical trials in ALS.
- Xia, Guoyao,Benmohamed, Radhia,Kim, Jinho,Arvanites, Anthony C.,Morimoto, Richard I.,Ferrante, Robert J.,Kirsch, Donald R.,Silverman, Richard B.
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experimental part
p. 2409 - 2421
(2011/06/19)
-
- Cyclodimerization and cyclotrimerization of isocyanates promoted by one praseodymium benzenethiolate complex [Pr(SPh)3(THF)3]
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The cyclotrimerization of aryl isocyanates and the cyclodimerization of alkyl isocyanates initiated by one praseodymium benzenethiolate complex [Pr(SPh)3(THF)3] were investigated. Comparative runs with [Pr(SPh)3(THF)3] and its precursor Pr[(Me 3Si)2N]3 showed that the former has the advantages of a higher selectivity toward isocyanates, easy preparation, low catalyst loading, high conversion as well as mild reaction conditions.
- Wang, He-Ming,Li, Hong-Xi,Yu, Xiang-Yang,Ren, Zhi-Gang,Lang, Jian-Ping
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experimental part
p. 1530 - 1535
(2011/04/15)
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- Direct synthesis of acyl azides from carboxylic acids using 2-azido-l,3-dimethylimidazolinium chloride
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Acyl azides were directly synthesized from carboxylic acids by the treatment with 2-azido-l,3-dimethylimidazolinium chloride (ADMC, 1) and amine. This procedure resulted in acyl azides in good yields and was applied to the amidation of amino acid derivatives without racemization of the products.
- Kitamura, Mitsuru,Tashiro, Norifumi,Takamoto, Yusuke,Okauchi, Tatsuo
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scheme or table
p. 731 - 733
(2011/01/08)
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- Synthesis of urea derivatives from amines and CO2 in the absence of catalyst and solvent
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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.
- Wu, Chaoyong,Cheng, Haiyang,Liu, Ruixia,Wang, Qiang,Hao, Yufen,Yu, Yancun,Zhao, Fengyu
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experimental part
p. 1811 - 1816
(2011/02/22)
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- Phenyl 4,5-dichloro-6-oxopyridazine-1(6H)-carboxylate as carbonyl source: Facile and selective synthesis of carbamates and ureas under mild conditions
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The selective syntheses of carbamates, symmetric -ureas, and unsymmetrical ureas have been accomplished by the -reaction of amines with phenyl 4,5-dichloro-6-oxopyridazine-1(6H)-carboxylate as a carbonyl source under mild conditions. It is noteworthy that this process is mild, economic, and convenient.
- Lee, Hyung-Geun,Kim, Min-Jung,Park, Song-Eun,Kim, Jeum-Jong,Kim, Bo Ram,Lee, Sang-Gyeong,Yoon, Yong-Jin
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experimental part
p. 2809 - 2814
(2010/03/03)
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- Cobalt/rhodium heterobimetallic nanoparticle-catalyzed oxidative carbonylation of amines in the presence of carbon monoxide and molecular oxygen to ureas
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An environmentally friendly oxidative carbonylation of aliphatic and aromatic primary amines to ureas has been successfully achieved in the presence of a catalytic amount of cobalt/rhodium heterobimetallic nanoparticles without any promoters. The catalyst system could be reused with only a slight loss of catalytic activity.
- Park, Ji Hoon,Yoon, Jae Chun,Chung, Young Keun
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supporting information; experimental part
p. 1233 - 1237
(2009/12/07)
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- A high yielding, one-pot synthesis of substituted ureas from the corresponding amines using Mitsunobu's reagent
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A Mitsunobu-based protocol has been developed for the synthesis of symmetrically and unsymmetrically substituted ureas from a variety of primary and secondary amines using gaseous carbon dioxide, in good to excellent yields. This protocol is mild and efficient compared to other reported methods.
- Chaturvedi, Devdutt,Mishra, Nisha,Mishra, Virendra
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experimental part
p. 267 - 270
(2009/05/26)
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- Pd(OAc)2-catalyzed carbonylation of amines
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A phosphine-free catalytic system [Pd(OAc)2-Cu(OAc) 2-air] induced a substrate-specific carbonylation of amines in boiling toluene under CO gas (1 atm). Symmetrical N,N′-dialkylureas were obtained by the carbonylation of primary amines. N,N,N′-Trialkylureas were selectively formed by addition of a secondary amine to the above reaction vessel. Secondary amines did not give tetraalkylureas. However, dialkylamines with a phenyl group on their alkyl chains, such as N-monoalkylated benzylic amine or phenethylamine derivatives, underwent a direct aromatic carbonylation to afford five- or six-membered benzolactams. In the carbonylation, the chelation effect or steric repulsion between Pd(II) and the meta-substituent in the ortho-palladation and the ring sizes of cyclopalladation products that were formed prior to carbonylation were found to generate good site selectivity and increase the reaction rate. In contrast, carbonylation of ω- arylalkylamines with a hydroxyl group gave neither ureas nor benzolactams but instead produced 1,3-oxazolidinones smoothly. Hydrochlorides of amines also underwent carbonylation to afford the corresponding amides under the conditions used. This procedure made it possible to prepare ureas of amino acid esters and N-alkylcarbamates in practical yields.
- Orito, Kazuhiko,Miyazawa, Mamoru,Nakamura, Takatoshi,Horibata, Akiyoshi,Ushito, Harumi,Nagasaki, Hideo,Yuguchi, Motoki,Yamashita, Satoshi,Yamazaki, Tetsuro,Tokuda, Masao
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p. 5951 - 5958
(2007/10/03)
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- Copper(II) reagent-promoted degradation of N,N′-dialkyldiazenedicarboxamides
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Degradation of N,N′-dialkyldiazenedicarboxamides with a copper(II) reagent, which was prepared from lithium 4-nitrophenoxide and copper(II) bromide in tetrahydrofuran, proceeded via formation of isocyanate to produce the corresponding 4-nitrophenyl N-alky
- Yamaguchi, Jun-Ichi,Murayama, Yukihito,Suyama, Takayuki
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p. 329 - 333
(2007/10/03)
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- N.C.A [11C]CO2 as a safe substitute for phosgene in the carbonylation of primary amines
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An efficient one-pot synthesis of [11C]ureas and [11C]isocyanates via dehydration of intermediately formed carbamate salts is described as a general alternative to their formation via [11C]phosgene. After optimization of the reaction parameters, in-target produced n.c.a. [11C]CO2 can be used for labelling in a one pot reaction within a very short reaction time of 10 minutes resulting in good radiochemical yields. The developed method has been applied to the 11C-carbonylation of aniline, benzyl- and phenethylamine and 1,2-diaminobenzene yielding the appropriate n.c.a. [11C]ureas in about 65, 85, 25 and 70% radiochemical yield (RCY), respectively. The presented reaction sequence can be handled easily and safely and lends itself to simple automation.
- Schirbel,Holschbach,Coenen
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p. 537 - 551
(2007/10/03)
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- Enzyme induction and comparative oxidative desulfuration of isothiocyanates to isocyanates
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Enzyme induction of oxidative metabolism of isothiocyanates to isocyanates by rat liver microsomes and comparative metabolic conversion of some isothiocyanates were investigated. Metabolic activity was assayed by trapping the isocyanate metabolites from isothiocyanates with the inclusion of 2-aminofluorene to form the respective mixed ureas as previously described for the 2-naphthyl isothiocyanate. Male F344 rats were fed either a conventional grain diet for induction with Aroclor 1254 or AIN 76A diet without antioxidant beginning 2 weeks before treatment with Aroclor 1254, β- naphthoflavone, isosafrole, or phenobarbital. Enzymes responsible for the metabolism of 1- and 2-naphthyl isothiocyanate were inducible by all four agents, Aroclor being the best under the current induction protocol and metabolic conversion assay procedure. On the other hand, enzymes responsible for the metabolism of benzyl isothiocyanate were induced only by Aroclor and, to a lesser extent, by phenobarbital. For the comparative metabolic conversion studies, using the microsomes from Aroclor-treated rats fed a conventional grain diet, the rates of metabolic conversion followed the order of 1-naphthyl >> phenyl > benzyl and phenethyl >> propyl, ethyl, and methyl isothiocyanates.
- Lee, Mei-Sie
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p. 1072 - 1078
(2007/10/03)
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- REACTION OF α-ACETYLBUTYROLACTONE WITH AMINES
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The reaction of α-acetylbutyrolactone and its ethylene ketal derivative with primary amines were investigated.Depending on the reaction conditions derivatives of butyrolactone (-) or urea (, ) or γ-hydroxybutyric acid (-) were obtained.The cyclisation reaction of γ-hydroxybutyric acid derivatives (-) to the corresponding 1,3-disubstituted pyrrolidinone-2 were also examined.Keywords: α-acetylbutyrolactone, γ-hydroxybutyric acid, elemental and spectral analysis, cyclization reaction
- Malawska, Barbara,Gorczyca, Maria
-
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- Ruthenium-Catalyzed Synthesis of Symmetrical N,N'-Dialkylureas Directly from Carbon Dioxide and Amines
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Aliphatic and araliphatic primary amines react with carbon dioxide at 120-140 deg C in the presence of ruthenium complexes and terminal alkynes, especilly propargyl alcohols, to directly afford N,N'-disubstituted symmetrical ureas.The alkyne ruthenium intermediate acts as a dehydrating reagent.This new and mild method avoids the classical use of carbonyl precursors like phosgene or isocyanates.
- Fournier, Jean,Bruneau, Christian,Dixneuf, Pierre H.,Lecolier, Serge
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p. 4456 - 4458
(2007/10/02)
-