- Mechanochemical reactions studied by in situ Raman spectroscopy: Base catalysis in liquid-assisted grinding
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In situ Raman spectroscopy was employed to study the course of a mechanochemical nucleophilic substitution on a carbonyl group. We describe evidence of base catalysis, akin to catalysis in solution, achieved by liquid-assisted grinding.
- Tireli, Martina,Juriba?i? Kulcsár, Marina,Cindro, Nikola,Gracin, Davor,Bili?kov, Nikola,Borovina, Mladen,?uri?, Manda,Halasz, Ivan,U?arevi?, Krunoslav
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Read Online
- Synthesis of Acyl Phosphoramidates Employing a Modified Staudinger Reaction
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A one-step synthesis of acyl phosphoramidates from a variety of functionalized acyl azides has been developed employing trimethylsilyl chloride as an activating agent in a modified Staudinger reaction. The methodology was further adapted to include the in situ generation of the acyl azides from a diverse selection of carboxylic acids and hydrazide starting synthons. The reaction scope was extended to include the synthesis of imidodiphosphates and the natural product Microcin C.
- Currie, Iain,Sleebs, Brad E.
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supporting information
p. 464 - 468
(2021/02/03)
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- Prodrugs for nitroreductase based cancer therapy-4: Towards prostate cancer targeting: Synthesis of N-heterocyclic nitro prodrugs, Ssap-NtrB enzymatic activation and anticancer evaluation
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In this study, various N-heterocyclic nitro prodrugs (NHN1-16) containing pyrimidine, triazine and piperazine rings were designed and synthesized. The final compounds were identified using FT-IR, 1H NMR, 13C NMR as well as elemental analyses. Enzymatic activities of compounds were conducted by using HPLC analysis to investigate the interaction of substrates with Ssap-NtrB nitroreductase enzyme. MTT assay was performed to evaluate the toxic effect of compounds against Hep3B and PC3 cancer cell lines and healthy HUVEC cell. It was observed that synthesized compounds NHN1-16 exhibited different cytotoxic profiles. Pyrimidine derivative NHN3 and triazine derivative NHN5 can be good drug candidates for prostate cancer with IC50 values of 54.75 μM and 48.9 μM, respectively. Compounds NHN6, NHN10, NHN12, NHN14 and NHN16 were selected as prodrug candidates because of non-toxic properties against three different cell models. The NHN prodrugs and Ssap-NtrB combinations were applied to SRB assay to reveal the prodrug capabilities of these selected compounds. SRB screening results showed that the metabolites of all selected non-toxic compounds showed remarkable cytotoxicity with IC50 values in the range of 1.71–4.72 nM on prostate cancer. Among the tested compounds, especially piperazine derivatives NHN12 and NHN14 showed significant toxic effect with IC50 values of 1.75 nM and 1.79 nM against PC3 cell compared with standart prodrug CB1954 (IC50: 1.71 nM). Novel compounds NHN12 and NHN14 can be considered as promising prodrug candidates for nitroreductase-prodrug based prostate cancer therapy.
- Güng?r, Tu?ba,Tokay, Esra,Güven Gülhan, ünzile,Hac?o?lu, Nelin,?elik, Ayhan,K??kar, Feray,Ay, Mehmet
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- Discovery of N-phenyl-(2,4-dihydroxypyrimidine-5-sulfonamido) phenylurea-based thymidylate synthase (TS) inhibitor as a novel multi-effects antitumor drugs with minimal toxicity
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Thymidylate synthase (TS) is a hot target for tumor chemotherapy, and its inhibitors are an essential direction for anti-tumor drug research. To our knowledge, currently, there are no reported thymidylate synthase inhibitors that could inhibit cancer cell migration. Therefore, for optimal therapeutic purposes, combines our previous reports and findings, we hope to obtain a multi-effects inhibitor. This study according to the principle of flattening we designed and synthesized 18 of N-phenyl-(2,4-dihydroxypyrimidine-5-sulfonamido)phenyl urea derivatives as multi-effects inhibitors. The biological evaluation results showed that target compounds could significantly inhibit the hTS enzyme, BRaf kinase and EGFR kinase activity in vitro, and most of the compounds had excellent anti-cell viability for six cancer cell lines. Notably, the candidate compound L14e (IC50 = 0.67 μM) had the superior anti-cell viability and safety to A549 and H460 cells compared with pemetrexed. Further studies had shown that L14e could cause G1/S phase arrest then induce intrinsic apoptosis. Transwell, western blot, and tube formation results proved that L14e could inhibit the activation of the EGFR signaling pathway, then ultimately achieve the purpose of inhibiting cancer cell migration and angiogenesis in cancer tissues. Furthermore, in vivo pharmacology evaluations of L14e showed significant antitumor activity in A549 cells xenografts with minimal toxicity. All of these results demonstrated that the L14e has the potential for drug discovery as a multi-effects inhibitor and provides a new reference for clinical treatment of non-small cell lung cancer.
- Li, Xin-yang,Zhang, Ting-jian,Kamara, Mohamed Olounfeh,Lu, Guo-qing,Xu, Hai-li,Wang, De-pu,Meng, Fan-hao
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- Direct conversion of carboxylic acids to various nitrogen-containing compounds in the one-pot exploiting curtius rearrangement
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Herein we report, a single-pot multistep conversion of inactivated carboxylic acids to various N-containing compounds using a common synthetic methodology. The developed methodology rendered the use of carboxylic acids as a direct surrogate of primary amines, for the synthesis of primary ureas, secondary/tertiary ureas, O/S-carbamates, benzoyl ureas, amides, and N-formyls, exploiting the Curtius reaction. This approach has a potential to provide a diversified library of N-containing compounds, starting from a single carboxylic acid, based on the selection of the nucleophile.
- Kumar, Arun,Kumar, Naveen,Sharma, Ritika,Bhargava, Gaurav,Mahajan, Dinesh
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p. 11323 - 11334
(2019/09/10)
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- Tert -Butyl nitrite mediated nitrogen transfer reactions: Synthesis of benzotriazoles and azides at room temperature
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A conversion of o-phenylenediamines into benzotriazoles was achieved at room temperature using tert-butyl nitrite. The optimized conditions are also well suited for the transformation of sulfonyl and acyl hydrazines into corresponding azides. This protocol does not require any catalyst or acidic medium. The desired products were obtained in excellent yields in a short span of time.
- Azeez, Sadaf,Chaudhary, Priyanka,Sureshbabu, Popuri,Sabiah, Shahulhameed,Kandasamy, Jeyakumar
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supporting information
p. 6902 - 6907
(2018/10/02)
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- Iridium(III)-Catalyzed Selective and Mild C-H Amidation of Cyclic N-Sulfonyl Ketimines with Organic Azides
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A general protocol for iridium catalyzed direct C?H amidation of cyclic N-sulfonyl ketimines using sulfonyl, acyl and aryl azides as nitrogen source is reported herein. The reaction takes place at room temperature with acyl and aryl azides, while an elevated temperature needed with sulfonyl azides to furnish aminated sultams in excellent yields with complete chemo and regioselectivity, thus providing a robust and environmentally benign process to the synthesis of aminosultams. (Figure presented.).
- Maraswami, Manikantha,Chen, Gang,Loh, Teck-Peng
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supporting information
p. 416 - 421
(2017/11/13)
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- Copper-catalyzed N[sbnd]H/S[sbnd]H functionalization: A strategy for the synthesis of benzothiadiazine derivatives
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A copper-mediated N[sbnd]S bond-forming reaction via N[sbnd]H/S[sbnd]H activation is described. This reaction occurs under mild conditions with high efficiency, step economy, and tolerates a wide variety of functional groups, providing an efficient means of accessing biologically important 1,2,4-benzothiadiazin-3(4H)-ones.
- Do?an, ?engül Dilem
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p. 2217 - 2224
(2017/03/24)
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- NOVEL PREPARATION METHOD OF QUINOLINE N-OXIDE DERIVATIVE WITH AMIDE GROUP
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Provided are a preparation method of a quinoline N-oxide derivative with an amide group capable of easily introducing the amide group into the quinoline N-oxide derivative by simplified processes and mild reaction conditions, and a quinoline N-oxide derivative with an amide group prepared by using the same.
- -
-
Paragraph 120-122
(2015/11/09)
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- Regioselective introduction of heteroatoms at the C-8 position of quinoline N-oxides: Remote C-H activation using N-oxide as a stepping stone
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Reported herein is the metal-catalyzed regioselective C-H functionalization of quinoline N-oxides at the 8-position: direct iodination and amidation were developed using rhodium and iridium catalytic systems, respectively. Mechanistic study of the amidation revealed that the unique regioselectivity is achieved through the smooth formation of N-oxide-chelated iridacycle and that an acid additive plays a key role in the rate-determining protodemetalation step. While this approach of remote C-H activation using N-oxide as a directing group could readily be applied to a wide range of heterocyclic substrates under mild conditions with high functional group tolerance, an efficient synthesis of zinquin ester (a fluorescent zinc indicator) was demonstrated.
- Hwang, Heejun,Kim, Jinwoo,Jeong, Jisu,Chang, Sukbok
-
supporting information
p. 10770 - 10776
(2014/08/18)
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- Iridium-catalyzed intermolecular amidation of sp3 C-H bonds: Late-stage functionalization of an unactivated methyl group
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Reported herein is the iridium-catalyzed direct amidation of unactivated sp3 C-H bonds. With sulfonyl and acyl azides as the amino source, the amidation occurs efficiently under mild conditions over a wide range of unactivated methyl groups with high functional group tolerance. This procedure can be successfully applied for the direct introduction of an amino group into complex compounds and thus can serve as a powerful synthetic tool for late-stage C-H functionalization.
- Kang, Taek,Kim, Youngchan,Lee, Donggun,Wang, Zhen,Chang, Sukbok
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supporting information
p. 4141 - 4144
(2014/04/03)
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- The challenge of palladium-catalyzed aromatic azidocarbonylation: From mechanistic and catalyst deactivation studies to a highly efficient process
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Azidocarbonylation of iodoarenes with CO and NaN3, a novel Heck-type carbonylation reaction, readily occurs in an organic solvent-H 2O biphasic system to furnish aroyl azides at room temperature and 1 atm. The reaction is catalyzed by Xantphos-Pd and exhibits high functional group tolerance. The catalyst deactivation product, [(Xantphos)PdI2], can be reduced in situ with PMHS to Pd(0) to regain catalytic activity. In this way, the catalyst loading has been lowered to 0.2% without any losses in selectivity at nearly 100% conversion to synthesize a series of aroyl azides in 80-90% isolated yield on a gram scale. Alternatively, the ArCON3 product can be used without isolation for further transformations in situ, e.g., to isocyanates, ureas, benzamides, and iminophosphoranes. A detailed experimental and computational study has identified two main reaction pathways for the reaction. For both routes, Ar-I oxidative addition to Pd(0) is the rate-determining step. In the presence of CO in excess, the Ar-I bond is activated by the less electron-rich Pd center of a mixed carbonyl phosphine complex. Under CO-deficient conditions, a slightly lower energy barrier pathway is followed that involves Ar-I oxidative addition to a more reactive carbonyl-free (Xantphos)Pd0 species. Mass transfer in the triphasic liquid-liquid-gas system employed for the reaction plays an important role in the competition between these two reaction channels, uniformly leading to a common aroyl azido intermediate that undergoes exceedingly facile ArCO-N 3 reductive elimination. Safety aspects of the method have been investigated.
- Miloserdov, Fedor M.,McMullin, Claire L.,Belmonte, Marta Martinez,Benet-Buchholz, Jordi,Bakhmutov, Vladimir I.,Macgregor, Stuart A.,Grushin, Vladimir V.
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supporting information
p. 736 - 752
(2014/03/21)
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- Ir(III)-catalyzed mild C-H amidation of arenes and alkenes: An efficient usage of acyl azides as the nitrogen source
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Reported herein is the development of the Ir(III)-catalyzed direct C-H amidation of arenes and alkenes using acyl azides as the nitrogen source. This procedure utilizes an in situ generated cationic half-sandwich iridium complex as a catalyst. The reaction takes place under very mild conditions, and a broad range of sp2 C-H bonds of chelate group-containing arenes and olefins are smoothly amidated with acyl azides without the intervention of the Curtius rearrangement. Significantly, a wide range of reactants of aryl-, aliphatic-, and olefinic acyl azides were all efficiently amidated with high functional group tolerance. Using the developed approach, Z-enamides were readily accessed with a complete control of regio- and stereoselectivity. The developed direct amidation proceeds in the absence of external oxidants and releases molecular nitrogen as a single byproduct, thus offering an environmentally benign process with wide potential applications in organic synthesis and medicinal chemistry.
- Ryu, Jaeyune,Kwak, Jaesung,Shin, Kwangmin,Lee, Donggun,Chang, Sukbok
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supporting information
p. 12861 - 12868
(2013/09/23)
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- Direct and facile synthesis of acyl azides from carboxylic acids using the trichloroisocyanuric acid-triphenylphosphine system
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A mild, efficient, and practical method for the one-step synthesis of acyl azides from carboxylic acids using a safe and inexpensive mixed reagent, trichloroisocyanuric acid-triphenylphosphine, is described.
- Akhlaghinia, Batool,Rouhi-Saadabad, Hamed
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p. 181 - 185
(2013/05/09)
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- One-pot, direct synthesis of acyl azides from carboxylic acids using Ph2PCl/I2/NaN3 reagent system
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A mild, efficient and simple method for the preparation of acyl azides from carboxylic acids using chlorodiphenylphosphine in the presence of molecular iodine and sodium azide is described.
- Nowrouzi, Najmeh,Zareh Jonaghani, Mohammad
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experimental part
p. 442 - 445
(2012/05/20)
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- Palladium-catalyzed aromatic azidocarbonylation
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Aryl iodides smoothly react with NaN3 and CO in the presence of a Pd/Xantphos catalyst to give aroyl azides (ArCON3) in 75-92 % yield. The reaction occurs under mild reaction conditions (1 atm, 20-50 °C) and exhibits high functional-group tolerance. (Xantphos=9,9-dimethyl-4,5- bis(diphenylphosphino)xanthene)
- Miloserdov, Fedor M.,Grushin, Vladimir V.
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supporting information; experimental part
p. 3668 - 3672
(2012/05/20)
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- FeCl36H2O-Catalyzed acceleration of the acylation of sodium azide with n-acylbenzotriazoles
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Catalyzed by ferric chloride hexahydrate (FeCl36H2O), the acylation of sodium azide with N-acylbenzotriazoles was greatly accelerated in a mixed solvent of acetone and water. Thus, good to excellent yields of a variety of acyl azides were obtained at room temperature in a short time. Furthermore, because of the complete conversion of N-acylbenzotriazoles and the easy removal of the by-product, purification by column chromatography was no longer required, which made the protocol suitable for large-scale preparation.
- Zhong, Zhiyun,Hu, Jieling,Wang, Xiaoxia,Liu, Junhua,Zhang, Longfeng
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experimental part
p. 2461 - 2467
(2011/08/05)
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- One-pot synthesis of symmetrical 1,3-diarylureas or substituted benzamides directly from benzylic primary alcohols and effective oxidation of secondary alcohols to ketones using phenyliodine diacetate in combination with sodium azide
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Benzylic primary alcohols can be directly converted into symmetrical 1,3-diarylureas or substituted benzamides via an one-pot oxidative reaction using the combined reagent of phenyliodine diacetate and sodium azide. This new reaction constitutes a step-economical way to prepare symmetric 1,3-diarylureas or substituted benzamides depending upon the substituents on the phenyl rings of starting alcohols. The sodium acetate generated in situ from the ligand exchange between phenyliodine diacetate and sodium azide plays the pivotal role in the formation of 1,3-diarylureas. In addition, it is also found that various secondary alcohols can be readily oxidized to their corresponding ketones in excellent yields using the same reagent system of phenyliodine diacetate and sodium azide. Generally, secondary alcohols are preferentially oxidized to the corresponding ketones in the presence of primary ones with the limited amounts of phenyliodine diacetate and sodium azide.
- Li, Xiao-Qiang,Wang, Wei-Kun,Han, Yi-Xin,Zhang, Chi
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experimental part
p. 2588 - 2598
(2010/12/25)
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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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- Facile one step synthesis of acyl azides and Nα-Fmoc/Boc/Z protected amino acid azides employing benzotriazole-1-yl-oxy-tris- (dimethylamino)-phosphonium hexafluorophosphate (BOP)
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A simple route for the preparation of acyl azides from the corresponding carboxylic acids employing the peptide-coupling agent BOP is described. The procedure is simple, clean and high yielding. The chemistry is also extended to the preparation of several urethane protected amino acid azides (eight examples) as well.
- Vasantha,Sureshbabu, Vommina V.
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experimental part
p. 812 - 817
(2011/01/04)
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- New and simple synthesis of acid azides, ureas and carbamates from carboxylic acids: Application of peptide coupling agents EDC and HBTU
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Conversion of carboxylic acids into acid azides using peptide coupling agents, EDC and HBTU is described. The procedure is efficient, practical and applicable to a diverse range of carboxylic acids including N-protected amino acids. Using the same reagents, one-pot synthesis of ureas, dipeptidyl urea esters and carbamates from acids has also been achieved. The Royal Society of Chemistry 2010.
- Sureshbabu, Vommina V.,Lalithamba,Narendra,Hemantha
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experimental part
p. 835 - 840
(2010/06/20)
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- Oxidative amidation and azidation of aldehydes by NHC catalysis
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Figure presented N-Heterocyclic carbene catalyzed oxidative amidations of various aldehydes to the corresponding hexafluoroisopropylesters by using the readily available organic oxidant A are described. The hexafluoroisopropylesters prepared in situ are shown to be highly useful active esters for amide bond formation. In addition, oxidative azidation of aldehydes is presented. These mild organocatalytic processes do not use any transition metal.
- De Sarkar, Suman,Studer, Armido
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supporting information; experimental part
p. 1992 - 1995
(2010/07/10)
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- An 'inside-out' approach to suramin analogues
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An approach to the synthesis of suramin analogues has been realised, which avoids synthetic problems associated with conventional routes. The use of isobutyl ester protecting groups for sulfonic acids was crucial to the success of the strategy, because these were able to be cleanly deprotected with sodium iodide, yielding the sodium salts of the corresponding sulfonic acids.
- McGeary, Ross P.,Bennett, Andrew J.,Tran, Quoc B.,Prins, Johannes,Ross, Benjamin P.
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experimental part
p. 3990 - 3997
(2009/10/09)
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- The electronic absorption spectra of some acyl azides. Molecular orbital treatment
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The electronic absorption spectra of benzoyl azide and its derivatives: p-methyl, p-methoxy, p-chloro and p-nitrobenzoyl azide were investigated in different solvents. The observed spectra differ basically from the electronic spectra of aryl azides or alkyl azides. Four intense π-π* transitions were observed in the accessible UV region of the spectrum of each of the studied compounds. The contribution of charge transfer configurations to the observed transitions is rather weak. Shift of band maximum with solvent polarity is minute. On the other hand, band intensity is highly dependent on the solvent used. The observed transitions are delocalized rather than localized ones as in the case with aryl and alkyl azides. The attachment of the C{double bond, long}O group to the azide group in acyl azides has a significant effect on the electronic structure of the molecule. The arrangements as well as energies of the molecular orbitals are different in acyl azides from those in aryl azides. The first electronic transition in phenyl azide is at 276 nm, whereas that of bezoyle azide is at 251 nm. Ab initio molecular orbital calculations using both RHF/6-311G* and B3LYP/6-31+G* levels were carried out on the ground states of the studied compounds. The wave functions of the excited states were calculated using the CIS and the AM1-CI procedures.
- Abu-Eittah, Rafie H.,Mohamed, Adel A.,Farag,Al Omar, Ahmed M.
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p. 177 - 186
(2008/09/20)
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- Direct synthesis of acyl azides from carboxylic acids by the combination of trichloroacetonitrile, triphenylphosphine and sodium azide
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Various carboxylic acids were converted into acyl azides in excellent yields by treating with trichloroacetonitrile, triphenylphosphine and sodium azide at room temperature. The reaction was applicable to the preparation of dipeptide without rearrangement.
- Kim, Joong-Gon,Jang, Doo Ok
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experimental part
p. 2072 - 2074
(2009/04/07)
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- Direct, facile synthesis of acyl azides and nitriles from carboxylic acids using bis(2-methoxyethyl)aminosulfur trifluoride
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A mild, efficient, and practical method for the one-step synthesis of acyl azides from carboxylic acids using bis(2-methoxyethyl)aminosulfur trifluoride is described. The reaction was easily extended to the synthesis of the corresponding nitriles by the inclusion of phosphorous reagents. The method can be applied to the synthesis of optically active nitriles in high yields, and is compatible with fluorous phosphines.
- Kangani, Cyrous O.,Day, Billy W.,Kelley, David E.
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p. 5933 - 5937
(2008/02/10)
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- Direct conversion of aldehydes to acyl azides using tert-butyl hypochlorite
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A general method, for the direct conversion of aldehydes to acyl azides using tert-butyl hypochlorite and sodium azide is described. The method is simple and occurs under mild conditions.
- Arote, Nitin D.,Akamanchi, Krishnacharya G.
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p. 5661 - 5664
(2008/02/10)
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- Radical substitution with azide: TMSN3-PhI(OAc)2 as a substitute of in3
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TMSN3 and PhI(OAc)2 were found to promote high-yield azide substitution of ethers, aldehydes and benzal acetals. The reaction is fast and occurs at zero to ambient temperature in acetonitrile. However, it is essential for the reaction that TMSN3 is added subsequent to the mixture of PhI(OAc)2 and the substrate. A primary deuterium kinetic isotope effect was found for the azidonation of benzyl ethers both with TMSN3-PhI(OAc)2 and with IN3. Also a Hammett free energy relationship study of this reaction showed good correlation with σ+ constants giving with ρ-values of -0.47 for TMSN 3-PhI(OAc)2 and -0.39 for IN3. On this basis a radical mechanism of the reaction was proposed. The Rayal Society of Chemistry 2005.
- Pedersen, Christian Marcus,Marinescu, Lavinia Georgeta,Bols, Mikael
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p. 816 - 822
(2007/10/03)
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- Preparation of acyl azides from aromatic carboxylic acids using triphosgene in ionic liquids
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Acyl azides are obtained in high yields from aromatic carboxylic acids and sodium azide at room temperature in ionic liquids using triphosgene as a synthetic auxiliary under mild reaction conditions and with a short reaction time.
- Bao, Weiliang,Wang, Qiang
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p. 700 - 701
(2007/10/03)
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- Iodine(V) reagents in organic synthesis. Dess-Martin periodinane mediated efficient one-pot oxidation of aldehydes to acyl azides
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A mild, efficient and general method for the one-step preparation of acyl azides from aldehydes using Dess-Martin periodinane and sodium azide is described.
- Bose, D. Subhas,Reddy, A. V. Narsimha
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p. 3543 - 3545
(2007/10/03)
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- Synthesis of novel azo dyes derived from 4-phenylurazole
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A novel and convenient method for the preparation of 4-(4-aminophenyl) urazole has been developed. Protic diazotization of amino group of this compound and subsequent coupling reaction with some electron rich aromatic compounds such as phenols, naphthols, and anilines lead to the formation of novel azo dyes with a phenylurazole linkage in moderate to high yields.
- Mallakpour, Shadpour E.,Nasr-Isfahani, Hossein
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p. 169 - 174
(2007/10/03)
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- Reinterpretation of curved hammett plots in reaction of nucleophiles with aryl benzoates: Change in rate-determining step or mechanism versus ground-state stabilization
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A kinetic study is reported for the reaction of the anionic nucleophiles OH-, CN-, and N3- with aryl benzoates containing substituents on the benzoyl as well as the aryloxy moiety, in 80 mol % H2O-20 mol % dimethyl sulfoxide at 25.0 °C. Hammett log k vs σ plots for these systems are consistently nonlinear. However, a possible traditional explanation in terms of a mechanism involving a tetrahedral intermediate with curvature resulting from a change in rate-determining step is considered but rejected. The proposed explanation involves ground-state stabilization through resonance interaction between the benzoyl substituent and the electrophilic carbonyl center in the two-stage mechanism. Accordingly, the data are nicely accommodated on the basis of the Yukawa-Tsuno equation, which gives linear plots for all three nuceophiles. Literature reports of the mechanism of acyl transfer processes are reconsidered in this light.
- Um, Ik-Hwan,Han, Hyun-Joo,Ahn, Jung-Ae,Kang, Swan,Buncel, Erwin
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p. 8475 - 8480
(2007/10/03)
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- Synthesis of acyl azides from carboxylic acids using cyanuric chloride
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A mild, efficient and general method for the preparation of acyl azides from carboxylic acids and sodium azide using cyanuric chloride is described.
- Bandgar,Pandit
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p. 3413 - 3414
(2007/10/03)
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- 3,4,5-Trifluorobenzeneboronic acid: A mild and versatile catalyst for the one-pot synthesis of acyl azides from carboxylic acids
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Acyloxyboron intermediates generated from carboxylic acids and 3,4,5-trifluorobenzeneboronic acid react with sodium azide to furnish the corresponding acyl azides in moderate to good yields.
- Tale,Patil
-
p. 9715 - 9716
(2007/10/03)
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- A mild and efficient method for the preparation of acyl azides from carboxylic acids using triphosgene
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An efficient use of triphosgene for the preparation of various acyl azides from carboxylic acids and sodium azide is described.
- Gumaste,Bhawal,Deshmukh
-
p. 1345 - 1346
(2007/10/03)
-
- A new facile and rapid synthesis of acyl azides under solvent-free conditions
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A rapid and simple method for the preparation of acyl azides is described. The reaction is carried out under solvent-free conditions from the reaction of acid chlorides with sodium azide supported on silica gel.
- Mallakpour,Hajipour,Vahabi
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p. 1234 - 1235
(2007/10/03)
-
- Hypervalent iodine in synthesis. Part 54: One-step conversion of aryl aldehydes to aroyl azides using a combined reagent of (diacetoxyiodo)benzene with sodium azide
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Aroyl azides are readily prepared from the corresponding aryl aldehydes with the aid of (diacetoxyiodo)benzene (DIB) and sodium azide in high yields. (C) 2000 Elsevier Science Ltd.
- Chen,Chen
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p. 7361 - 7363
(2007/10/03)
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- Rapid construction of isatin derivatives via addition of bis(alkylthio)carbenes to aryl isocyanates
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Thermally induced cyclization between bis(alkylthio)carbenes, derived from the corresponding oxadiazolines, and substituted aryl isocyanates provides access to a variety of isatin derivatives with good efficiency.
- Rigby, James H.,Danca, M. Diana
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p. 6891 - 6894
(2007/10/03)
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- Nitrosation with Sodium Hexanitrocobaltate(III)
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Na3Co(NO2)6 has been investigated as a new reagent for the nitrosation of various substrates containing an amino functionality. Reactions took place in an aqueous solution of the reagent. The pH of the reaction mixture remained in the range 4.3-5. Thus, hydrazides were transformed to the corresponding acyl azides, and the reactions with arenesulfonyl hydrazines afforded arenesulfonyl azides. Treatment of aromatic amines with Na3Co(NO2)6 gave 1,3-diaryltriazenes in excellent yields; coupling of the initially formed diazo compound to the electron rich aromatic ring was also observed. Nitrosation of aliphatic amines was not possible due to complex formation with the reagent.
- Stefane, Bogdan,Kocevar, Marijan,Polanc, Slovenko
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p. 7165 - 7169
(2007/10/03)
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- Oxidation of aldehydes to acyl azides using triazidochlorosilane (TACS)-active manganese dioxide reagent
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Triazidochlorosilane (TACS)-active manganese dioxide is a new and versatile system for the efficient oxidation of aldehydes to the corresponding acyl azides at 0°C, in dichloromethane.
- Elmorsy, Saad S.
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p. 1341 - 1342
(2007/10/02)
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- Saponification agents. 2. Synthesis of arylisocyanates with ethyl lactate and their use in racemic bases saponification
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Reaction of the arylisocyanates 2a-c with ethyl (S)-(-)-lactate, followed by careful saponification, afforded the corresponding chiral acids (S)-(-)- 4a-c. The latter were successfully used for the resolution of various racemic bases belonging to both the ephedrine and α-aryl ethylamine series.
- Brown,Moudachirou
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p. 10309 - 10320
(2007/10/02)
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- ONE-FLASK SYNTHESIS OF ACYL AZIDES FROM CARBOXYLIC ACIDS; A FACILE ROUTE TO IMINOPHOSPHORANES
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Carboxylic acids react with a mixture of N-chlorosuccinimide, triphenylphosphine and sodium azide at -30 deg C to form acyl azides in high yields.When two equivalents of triphenylphosphine are applied and the temperature allowed to raise, the reaction yields directly α-carbonyl stabilized iminophosphoranes via Staudinger reaction of the phosphine with the intermediate acyl azide.Key words: Iminophosphoranes; acyl azides; one-flask synthesis.
- Froeyen, Paul
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- A PARTICULARLY CONVENIENT ONE-POT SYNTHESIS OF N-ALKOXYCARBONYL, N-ACYL AND N-AROYL SUBSTITUTED IMINOPHOSPHORANES; IMPROVED PREPARATION OF AZIDOFORMATES, AROYL AND ALKANOYL AZIDES; AN ALTERNATIVE ROUTE TO COMPLEX AMIDES
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Chloroformates and acid chlorides react smoothly with sodium azide in acetone at 0 deg C, forming azidoformates, aroyl and alkanoyl azides in very high yield.With triphenylphosphine or other phosphines present in the reaction mixture, the forming azides are intercepted, leading directly to the corresponding N-alkanoyl, N-aroyl, N-alkoxycarbonyl, and N-aryloxycarbonyliminophosphoranes.N-acyliminophosphoranes react with n-butyllithium forming anions which react readily with electrophiles, e.g., carbonyl compounds, forming highly substituted iminophosphoranes.The phosphonium group is effortlessly removed from the latter compounds by acid hydrolysis forming the corresponding amides in high yield.Key words: Synthesis; iminophosphoranes; aroyl azides; alkanoyl azides; complex amides.
- Froeyen, Paul
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p. 161 - 172
(2007/10/02)
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- Synthesis of acyl azides via polymer-supported reagent
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Acyl azides have been synthesised in high yields and in a state of high purity by reacting acyl chloride with polymer-supported azide ion reagent.
- Thorat, M. T.,Mane, R. B.,Deshmukh, J. G.,Salunkhe, M. M.,Wadgaonkar, P. P.
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p. 186 - 187
(2007/10/02)
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- FACILE SYNTHESIS OF AZIDES: CONVERSION OF HYDRAZINES USING DINITROGEN TETROXIDE
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Various hydrazines such as aryl-, carbonyl-, and sulfonylhydrazine were reacted with dinitrogen tetroxide to give the corresponding azides in excellent yields under mild conditions at low temperature (-20 to ca.-40 deg C) in acetonitrile.
- Kim, Yong Hae,Kim, Kweon,Shim, Sung Bo
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p. 4749 - 4752
(2007/10/02)
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- THE FORMATION AND METABOLISM OF n-HYDROXYMETHYL COMPOUNDS. PART 6.1 THE SYNTHESIS OF S-AMIDOMETHYL-, S-UREIDOMETHYL-, AND S-(1,3,5-TRIAZIN-2-YLAMINOMETHYL)-GLUTATHIONE DERIVATIVES
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Treatment of N-hydroxymethyl and N-alkoxymethyl compounds with glutathione or N-acetylcysteine in trifluoroacetic acid affords the corresponding glutathione or N-acetylcysteine derivatives in high yield.Alkoxymethylureas are formed by the condensation of ureas with formaldehyde and alcohols under basic conditions; the implications of this observation are discussed with reference to possible biochemical mechanisms.
- Addison, Sally J.,Cunningham, Bernadette D. M.,Gate, E. Nicholas,Shah, Prakash Z.,Threadgill, Michael D.
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