- Atom-economic thiophosphoroselenenylations of C–H acid esters and amides
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Three improved thiophosphoroselenenylation procedures of CH-acids, including derivatives of malonic and acetyl-, phosphono-, 4-nitrophenyl- and 3-pyridylacetic acids, have been described and compared to previously reported thiophosphoroselenylation of diethyl malonate using bis(disopropoxyphosphinothioyl)diselenide alone or with the aid of methyl iodide. The use of iodine makes it possible to utilize both equivalents of the selenenylating agent. The procedures work well for the majority of nucleophiles in a pKa range between more acidic malononitrile or Meldrum acid and less acidic phenylacetates. The reaction carried out on diethyl malonate in boiling rectified ethanol yields selenoacetate, which cannot be obtained by direct phosphoroselenenylation. Crystal structure of one of the selenomalonamides confirms the stabilization effects of both carbonyl oxygens on selenium atom. The P-Se bond splitting, using TBAF in 3-molar excess in the presence of alkylating agent yields the respective C,Se-dialkyl derivatives.
- Majewski, Arkadiusz,Przychodzeń, Witold
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p. 3390 - 3402
(2021/11/17)
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- Visible-light-induced photocatalyst-free C-3 functionalization of indoles with diethyl bromomalonate
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A visible-light induced green and efficient method is developed for the synthesis of α-indolyl diethyl malonates. The reaction proceeds without any photocatalysts or ligands in a green solvent in a short time. Moreover, the reaction mechanism has been clearly studied by control experiments, spectrophotometric studies and density functional theory (DFT) calculations. The results showed that the photocatalyst-free transformation may proceed via an XB-promoted radical process. The EDA complex formation of diethyl bromomalonate with a base is the main reason for the reaction initiation.
- Gu, Guangmiao,Huang, Mengmeng,Kim, Jung Keun,Li, Yabo,Wu, Yangjie,Zhang, Jianye
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supporting information
p. 2543 - 2548
(2020/05/13)
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- Reaction of N-chloroamines with carbanions derived from ethyl acetoacetate and diethyl malonate
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Carbanions derived from ethyl 3-oxobutanoate and diethyl malonate reacted with an equimolar amount of N-chloro-N-ethylethanamine, N-chloromorpholine, or N-chloropiperidine to give diethyl 2,3-diacetylbutanedioate and tetraethyl ethane-1,1,2,2-tetracarboxylate in 68–83% yield. The possibility of heterocoupling of ethyl 3-oxobutanoate and diethyl malonate carbanions by the action of N-chloro-N-ethylethanamine and the effect of the molar reactant ratio on the selectivity of oxidative homo- and heterocoupling were studied.
- Zorin,Zainashev,Zorin
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p. 1685 - 1688
(2017/09/25)
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- Catalytic Access to Alkyl Bromides, Chlorides and Iodides via Visible Light-Promoted Decarboxylative Halogenation
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Herein is reported the catalytic, visible light-promoted, decarboxylative halogenation (bromination, chlorination, and iodination) of aliphatic carboxylic acids. This operationally-simple reaction tolerates a range of functional groups, proceeds at room temperature, and is redox neutral. By employing an iridium photocatalyst in concert with a halogen atom source, the use of stoichiometric metals such as silver, mercury, thallium, and lead can be circumvented. This reaction grants access to valuable synthetic building blocks from the large pool of cheap, readily available carboxylic acids.
- Candish, Lisa,Standley, Eric A.,Gómez-Suárez, Adrián,Mukherjee, Satobhisha,Glorius, Frank
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supporting information
p. 9971 - 9974
(2016/07/19)
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- Sequential fullerenylation of bis-malonates-efficient access to oligoclusters with different fullerene building blocks
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A method for the sequential fullerenylation of bis-malonates with parent C60 and C2v-symmetric pentakis-adducts is reported. This approach relies on the finding that (a) chloromalonates can be used for the nucleophilic cyclopropanation of [6,6] double bonds of C60, and (b) chloromalonates, in contrast to bromomalonates, do not undergo base-catalyzed halogen exchange reactions. For the proof of concept, we synthesized a heptafullerene by using a divergent approach based on a fullerene hexakis-adduct with six bis-malonate addends in octahedral positions, each of which is suitable for an additional cyclopropanation of a fullerene building block. A sequence for the selective fullerenylation of bis-malonates with C60 and its exohedral C2v-symmetric pentakis-adducts has been developed. This method enables the straightforward synthesis of highly functional fullerene derivatives such as the heptafullerene 1.
- Wasserthal, Lennard K.,Kratzer, Andreas,Hirsch, Andreas
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p. 2355 - 2361
(2013/05/22)
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- Bromophilic substitution/carbophilic substitution cascade reactions of α,α-dibromo-2-methoxyacetophenone with C-, N- and O-nucleophiles
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α,α-Dibromo-2-methoxyacetophenone reacts, under mild reaction conditions, with C-, N- and O-nucleophiles via a bromophilic substitution/protonation/carbophilic substitution cascade process to afford α-monosubstituted-2-methoxyacetophenones in moderate to good yield. The only exception from this reaction pathway is the reaction with the anion derived from malononitrile in which 2-aroyl-1,1,3,3-tetracyanopropene is obtained.
- Tatar, Jovana,Markovi?, Rade,Stojanovi?, Milovan,Baranac-Stojanovi?, Marija
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experimental part
p. 4851 - 4855
(2010/10/02)
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- Asymmetrie synthesis of (+)- and (-)-wuweizisu C stereoisomers and their chemosensitizing effects on multidrug-resistant cancer cells
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Total syntheses of the dibenzocyclooctadiene natural product wuweizisu C in its (-)-form [(S)-1] and its (+)-form [(R)-l] were achieved in 19 steps, starting from commercially available gallic acid. In the key step, the asymmetric biphenyl axis was constructed by an oxazoline-mediated Ullmann reaction to provide either the P or Mbiaryl product in 68% yield and >99% de, depending on the configuration of the oxazoline. The efficiency of this total synthesis was excellent, as the syntheses of (S)-1 and (R)-1 from, intermediate 7 each proceeded in 13 steps with an overall yield of 6.8%. (S)-1 and (R)-1 were evaluated as chemosensitizers for multidrug-resistant cancers.
- Li, Yanfeng,Wang, Qiang,Dong, Lihong,Guo, Xiaohe,Wang, Wei,Xie, Jingxi,Chang, Junbiao
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experimental part
p. 3383 - 3390
(2010/02/28)
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- Efficient selective formation of C-C single bonds and C=C double bonds by NBS-promoted oxidative coupling of β-keto esters
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A new application of NBS, which results in the oxidative coupling of β-keto esters to selectively form C-C single and C=C double bonds, can be controlled by the amount of NBS and t-BuOK employed. This methodology adds a new entry to C-C single and C=C double-bond formation between active methylene groups under mild conditions with high selectivity. Copyright Taylor & Francis Group, LLC.
- Wang, Zhiguo,Yin, Guodong,Chen, Aihua,Hu, Shengli,Wu, Anxin
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p. 4399 - 4405
(2008/03/14)
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- Alkylation of 3,4-dibromo-4-methyltetrahydropyran with diethyl malonate as a key to understanding the electronic nature of chemo- and regioselectivity of molecules
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The reaction of 3,4-dibromo-4-methyltetrahydropyran with diethyl malonate in the presence of sodium butoxide leads to formation of the corresponding cross-coupling product rather than of tetraethyl ethane-1,1,2,2-tetracarboxylate (product of dehydrodimerization of diethyl malonate) which is formed in the presence of sodium ethoxide. An explanation was proposed, which may be regarded as a key to understanding the nature of the driving force for one- and two-electron transfer, as well as chemo- and regioselectivity of organic molecules. 2005 Pleiades Publishing, Inc.
- Gevorkyan,Arakelyan,Dzhandzhulyan,Mikaelyan,Petrosyan,Panosyan
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p. 134 - 140
(2007/10/03)
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- Novel pyrrolo-quinoline derivatives as potent inhibitors for PI3-kinase related kinases
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Several pyrrolo-quinoline γ-lactones were found as novel inhibitors for two members of the PI3-kinase related kinase (PIKK) family. Ataxia-Telangiectasia-mutated (ATM) protein and the mammalian Target of Rapamycin (mTOR). Preliminary structure-activity relationship studies indicated that an electrophilic exocyclic double bond conjugated to the carbonyl group of the γ-lactone ring was crucial for the PIKK inhibitory potency. One of the best ATM inhibitors in this series, DK8G557, showed IC50 values of 0.6 and 7.0 μM for ATM and mTOR, respectively. This compound exhibited potent and selective growth inhibition activities in the NCI 60 human tumor cell line screen with a GI50 MG-MID value of 2.69 μM. The best mTOR inhibitor in this series, HP9912, exhibited IC50 values of 0.5 and 6.5 μM for mTOR and ATM, respectively. These compounds suggest novel leads for the discovery of potent small molecule inibitors of PIKKs as potential anticancer drugs, with therapeutic activities as either single, or as sensitizing agents to conventional radio-, or chemo-therapeutic strategies. Copyright
- Peng, Hairuo,Kim, Doeg-Il,Sarkaria, Jann N,Cho, Yong-Seo,Abraham, Robert T,Zalkow, Leon H
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p. 167 - 174
(2007/10/03)
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- Oxidative Dimerization of CH Acids
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Anodic oxidation of alkyl- (1) and acylmalonic acid esters (7) yields the dehydrodimers 4 and 8, respectively.Preparative electrolyses are performed in acetonitrile in the presence of a base to generate the carbanion corresponding to the CH acid.The carbanions are oxidized to the radicals which dimerise on the electrode surface.The yields of the preparative electrolyses and the formation of the dehydrodimers 4 and 8 are discussed in terms of the CH acidity and enolization of the starting materials. - Key Words: Electrochemistry / Oxidation, anodic / CH Acids / Dehydrodimerization
- Peek, Reinhold,Streukens, Marlies,Thomas, Hans Guenter,Vanderfuhr, Andre,Wellen, Ulrich
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p. 1257 - 1262
(2007/10/02)
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- Reactivity of 2-chloro- and 2-(tosyloxy)cyclohexanones towards anions electrogenerated at carbonium and nitrogen atoms. Electrochemically induced Favorskii rearrangement
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Carbonium and nitrogen anions were generated by cathodic reduction of 6, 7 and 8 or by deprotonation of 9 and 10 (by means of electrogenerated bases).Their reactivity towards α-substituted ketones 1 and 2 was studied.The reaction products 5b-d, 4b and 3 are formed according to the Favorskii rearrangement, substitution, and formal reduction mechanisms, respectively.In most cases, the reaction pathway appears to be driven by the applied electric potential.The Favorskii rearrangement undergone by 1 and 2 under electrochemical conditions can also be induced by nitrogen (Ph-NH--Ph) and carbonium (CH3COC-HCO2Et) anions, which have never been used before in this kind of reaction. - Keywords: probase / Favorskii rearrangement / electrogenerated anions / α-substituted cyclohexanones
- Angelis, F. De,Feroci M.,Inesi, A.
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p. 712 - 719
(2007/10/02)
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- Potassium fluoride on alumina: Oxidative coupling of acidic carbon compounds with diiodine
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Diiodine reacts at room temperature with activated methylene compounds in the presence of potassium fluoride on alumina and saturated dimers, unsaturated dimers or trimers were formed according to the stoechiometry of the reaction. The reactions were improved by using ultrasound activation.
- Villemin,Alloum
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p. 3169 - 3179
(2007/10/02)
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- Reactivity of a Cyclic α-Bromoiminium Bromide towards Nucleophiles
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Piperidine-pyrrolidine ring contraction of 1-piperideinium bromide (1) was observed by reaction with aqueous bases, sodium methoxide, phenylhydrazine, (S)-1-phenylethylamine and sodium borohydride, whereas diazomethane addition mainly gave pyrrolopyridine derivative 8.Some stereochemical features of these reactions have been investigated. 1 gave back bromine under suitable conditions.
- Donati, Donato,Fusi, Stefania,Macripo, Maria Adelaide,Ponticelli, Fabio
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p. 481 - 483
(2007/10/02)
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- MACROHETEROCYCLES. 31. BINUCLEAR CROWN ETHERS BASED ON 1,1,2,2-TETRAHYDROXYMETHANYLETHANE
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Methods for the synthesis and production of a number of new binuclear crown ethers based on 1,1,2,2-tetrahydroxymethylethane and its derivatives were developed.
- Luk'yanenko, N. G.,Mel'nik, O. T.
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p. 934 - 939
(2007/10/02)
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- Reduction-alkylation with organocopper(I) reagents-alkyl halydes: Highly regioselective α-alkylation of γ-acetoxy-α,β-enoates with lithium dibutylcuprate-alkyl halides and difference in the reactivity of electron-deficient olefins with organocopper(I)-Lewis acid reagents
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Reaction of γ-acetoxy-α,β-enoates with lithium dialkylcuprate followed by alkyl halides results in the predominant or exclusive formation of α-alkyl-β,γ-enoates in high yields under mild conditions, and a synthetic application to (+-)-α-vetispirene is presented.Treatment of diethyl fumarate and triethoxycarbonylethylene with Bu2CuLi*AlCl3 led to 1,4-addition to give conjugate adducts in high yields.In sharp contrast, diethyl maleate and tetraethoxycarbonylethylene predominantly gave the respective reduction products.Evidence for a presumed dianionic intermediate, based on trapping with some electrophyles, is also presented.Keywords - γ-oxygenated α,β-enoate; β,γ-enoate; deconjugative reduction; α-vetispirene; lithium dialkylcuprate; organocopper(I)-Lewis acid.
- Ibuka, Toshiro,Aoyagi, Takeshi,Yamamoto, Yoshinori
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p. 2417 - 2427
(2007/10/02)
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- Studies on fluoroalkylation and fluoroalkoxylation. Part 10. Electron-transfer induced reactions of perfluoroalkyl iodides and the dialkyl malonate anion and β-fragmentation of the halotetrafluoroethyl radical
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Fluoroalkyl iodides, XCF2CF2I (X=F, perfluoroalkyl group) (1), react readily with malonic ester anion (2) in DMF to give {A figure is presented} (3), 1-hydroperfluoroalkane (4) and dimer of the anion (5). The reaction is accelerated by UV irradiation and partly suppressed by p-DNB. Diallyl ether (DAE) can trap the radical intermediates to afford five-membered ring products. Interestingly, in the case of 1 ( X = Cl, I ) the same reaction mainly yielded tetrafluoroethylene and 5 instead of 3 and 4. The radical intermediate XCF2CF·2 ( X=Cl ) can also be trapped by DAE to yield tetrahydrofuran derivatives. All these results can be rationalized in terms of the SRN1 mechanism.
- Chen, Qing-Yun,Qiu, Zai-Ming
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p. 301 - 317
(2007/10/02)
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- DIFFERENCES IN THE REACTION OF ELECTRON DEFICIENT OLEFINS WITH ORGANOCOPPER(I)-LEWIS ACID REAGENTS AND EVIDENCE FOR A DIANIONIC EQUIVALENT
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Treatment of diethyl fumarate and triethoxycarbonylethylene with Bu2CuLi*AlCl3 led to 1,4-addition to give butylated products in high yields.In sharp contrast, diethyl meleate and tetraethoxycarbonylethylene predominantly gave the respective reduction products.The first evidence for a presumed dianionic intermediate by trapping with some electrophiles was also presented.
- Ibuka, Toshiro,Aoyagi, Takeshi,Kitada, Kazuko,Yoneda, Fumio,Yamamoto, Yoshinori
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p. C18 - C22
(2007/10/02)
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- Thio-sugars. Part 6. Seco-nucleosides related to 4-thio-DL-erythrofuranose and 4-thio-DL-ribofuranose.
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The thio-sugar synthesis has been adapted to prepare seco-nucleosides, so named by analogy with steroids, for comparison with antiviral agents such as acycloguanosine.Bis(β-hydroxyethyl) sulphoxide gave, via a triacetate, crystalline 4'-thio-2',3'-seco-3'-norcytidine and similar nucleosides - also obtainable by successive action of NaIO4 and NaBH4 on the corresponding (much less soluble) 4-thioerythrosides.In unsymmetrical methyl sulphoxides, the presence of β-OH groups tends to reverse the direction of normal Pummerer rearrangement and both 1',2'-seco-2'-nor and 2',3'-dinoruridines were thus inaccessible: the latter have the acycloguanosine type side-chain.However, 2',3'-seco-3',5'-dinoruridines were readily isolated and in turn yielded 2,2'-but not 2',6-cyclonucleosides.The scope of these uridine cyclisations is briefly reviewed.
- McCormick, Joan E.,McElhinney, R. Stanley
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p. 256 - 281
(2007/10/02)
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