- PhICl2is activated by chloride ions
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A study on the potential activating role of pyridine in the electrophilic chlorination of anisole by PhICl2has led to the discovery that soluble sources of chloride ions activate PhICl2in the reaction at catalytic loadings, greatly increasing the rate of chlorination. It is further shown that presence of chloride increases the rate of decomposition of PhICl2into PhI and Cl2. The specific mechanism by which chloride induces electrophilic chlorination and decomposition of PhICl2remains an open question.
- Tania,Poynder, Tiffany B.,Kaur, Aishvaryadeep,Barwise, Lachlan,Houston, Sevan D.,Nair, Akshay J.,Clegg, Jack K.,Wilson, David J. D.,Dutton, Jason L.
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supporting information
p. 11986 - 11991
(2021/09/06)
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- UIII-CN versus UIV-NC coordination in tris(silylamide) complexes
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Treatment of the metallacycle [UN?2(N,C)] [N? = N(SiMe3)2; N,C = CH2SiMe2N(SiMe3)] with [HNEt3][BPh4], [HNEt3]Cl, and [pyH][OTf] (OTf = OSO2CFsu
- Hervé, Alexandre,Bouzidi, Yamina,Berthet, Jean-Claude,Belkhiri, Lotfi,Thuéry, Pierre,Boucekkine, Abdou,Ephritikhine, Michel
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p. 2474 - 2490
(2015/03/18)
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- Cycloadditions of siloxy alkynes with 1,2-diazines: From reaction discovery to identification of an antiglycolytic chemotype
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Cycloaddition uncovered: The title reaction produces novel polycyclic compounds with high efficiency and excellent diastereoselectivity under mild reaction conditions. A small-molecule library, synthesized using this reaction, yielded a novel chemotype which inhibited glycolytic ATP production by blocking glucose uptake in CHO-K1 cells. DMF=N,N-dimethylformamide, Tf= trifluoromethanesulfonyl, TIPS=triisopropylsilyl. Copyright
- Montavon, Timothy J.,Tuerkmen, Yunus E.,Shamsi, Noumaan A.,Miller, Christopher,Sumaria, Chintan S.,Rawal, Viresh H.,Kozmin, Sergey A.
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supporting information
p. 13576 - 13579
(2014/01/06)
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- 1,2-azaborine cations
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Positively brilliant: The first examples of 1,2-azaborine cations have been prepared and their structure and optoelectronic properties characterized (see picture). 1,2-Azaborine cations exhibit solid-state fluorescence that is distinct from their neutral all-carbon analogues, and the 1,2-azaborine moiety is a critical component for the optoelectronic properties. There is a potential for the utility of these complexes in materials applications.
- Marwitz, Adam J. V.,Jenkins, Jesse T.,Zakharov, Lev N.,Liu, Shih-Yuan
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supporting information; experimental part
p. 7444 - 7447
(2010/11/20)
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- Helquats: A facile, modular, scalable route to novel helical dications
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The synthesis and properties of helical extended diquat (helquat), and derivatives that bear resemblance to diquat and azoniahelicene, was reported. Triyne with elongated tethers connecting the heterocyclic moiety with the pendant alkyne functionalities u
- Adriaenssens, Louis,Severa, Lukas,Salova, Tereza,Cisarova, Ivana,Pohl, Radek,Saman, David,Rocha, Silvia V.,Finney, Nathaniel S.,Pospisil, Lubomir,Slavicek, Petr,Teply, Filip
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supporting information; experimental part
p. 1072 - 1076
(2009/10/21)
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- Penta-or tetrapeptide binding to somatostatin receptors and the use of the same
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The subject matter of the present invention is a cyclic or linear tetra- or pentapeptide binding to somatostatin receptors. The compounds of the invention are characterised in that they contain the radical of an amino carboxylic acid bearing a five-membered ring in the peptide backbone which may optionally contain O, S, Se, N, or P. These compounds are easy to prepare and display increased stability against peptidases. The compounds of the present invention induce apoptosis of tumour cells and the use of said compounds for cancer therapy is described. In particular, the compounds are characterised in that they are active even against tumour cells displaying resistance against other somatostatin derivatives such as octreotide. In addition, the use of the compounds of the invention for tumour diagnosis by means of positron-emission tomography is described, as well as their use as agents against neurogenic inflammation.
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- Antiinflammation agents
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Compounds, compositions and methods that are useful in the treatment of inflammatory, immunoregulatory, metabolic and cell proliferative conditions or diseases are provided herein. In particular, the invention provides compounds which modulate the expression and/or function of proteins involved in inflammation, metabolism and cell proliferation. The subject compounds contain fused carbocyclic or heterocyclic rings.
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- Reaction of N-fluoropyridinium salts with Wittig reagents: A novel and convenient approach to symmetric trans-olefins
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N-Fluoropyridinium salts were found to react with Wittig reagents containing electron-withdrawing groups to give olefins in 47-83% yield. The mechanism of this conversion is believed in involve single-electron transfer from Wittig reagent to N-fluoropyridinium cation.
- Kiselyov, Alexander S.
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p. 8951 - 8954
(2007/10/02)
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- Preparation of homo- and heterobimetallic μ-η2-(C,C)-ketene complexes, FpCH2COMLn, and transformation of the bridging ketene ligand into various C2 functional groups
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Eight examples of homo- and heterobimetallic μ-ketene complexes, FpCH2COMLn [3-7: Fp = (η5-C5H5)Fe(CO)2; M = Fe, Mo, Ni, Mn, Co; L = Cp, CO, PR3], are prepared by acylation of an iron-substituted acetyl chloride with various transition-metal anions. IR studies reveal the significant contribution of a π-complex Fp+[CH2=C(O-)Fp] (10) in addition to an oxycarbene structure FpCH2C(O-)=Fp+ (11) which is well-established for mononuclear acyl complexes. As a typical example, FpCH2COFp (3a) is subjected to chemical transformations relevant to catalytic CO hydrogenation. While 3a is not susceptible to carbonylation to lead to a μ-malonyl complex, decarbonylation results in quantitative liberation of ketene molecule or ligand substitution instead of formation of a μ-methylene complex. Reduction of 3a by LiAlH4 affords C3 products as major components. Reaction of 3a with electrophiles takes place at the acyl oxygen atom to give cationic binuclear oxycarbene complexes FpCH2C(OR)=Fp+TfO- (TfO = CF3SO3) (18-20) which exhibit bimodal reactivities toward both nucleophiles and electrophiles. Hard nucleophiles attack the most electrophilic carbene center, soft nucleophiles attack the alkyl side Fp group, and electrophilic reaction takes place at the methylene terminus.
- Akita, Munetaka,Kondoh, Atsuo,Kawahara, Takashi,Takagi, Takenobu,Moro-oka, Yoshihiko
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p. 366 - 374
(2008/10/08)
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- TRIFLUOROMETHANESULPHONIC ACID AS A CATALYST FOR THE ETHYLATION OF BENZENE
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At room temperature and a pressure of ethene of 1 atm, anhydrous trifluoromethanesulfonic (triflic) acid is a more effective catalyst for the ethylation of benzene than AlCl3, FSO3H, and anhydrous H2SO4.It has an activity comparable to that found for a 1:1 mixture of FSO3H-SbF5, and under the most favourable conditions the yield of ethylbenzene is ca. 38percent based on the amount of benzene reacted.Although the initial rate of ethylation is rapid, the raction effectively ceases after 30-60 min depending on the reaction conditions.The reason for this has mainly been shown to be strong complexation of the triflic acid to polyethylbenzene derivatives in the catalyst layer, but also, in part to the competing formation of ethyl triflate, wich is inactive as an ethylating agent under the conditions used.
- Booth, Brian L.,Al-Kinany, Mohammed,Laali, Khosrow
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p. 2049 - 2056
(2007/10/02)
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- α-Fluorination of Sulfides with N-Fluoropyridinium Triflates
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The reaction of sulfides possessing α-hydrogen with various N-fuoropyridinium salts was examined.While the fluorinating power increased in the order of N-fluoro-2,4,6-trimethylpyridinium triflate 12, and 3 no longer produced the α-fluoro sulfide.Triflate 1 was more reactive than the corresponding tetrafluoroborate 4.Thus, it was shown that 1 satisfactorily fluorinated various kinds of sulfides under very mild conditions, giving α-fluoro sulfides.A two-step mechanism, oxidative fluorination of sulfur and Pummerer-type rearrangement, was proposed for the fluorination.The corresponding α-fluoro sulfoxide or sulfones were easily prepared from the sulfides by successive fluorination-oxidation procedure.
- Umemoto, Teruo,Tomizawa, Ginjiro
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p. 3625 - 3630
(2007/10/02)
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