- Enabling the Use of Alkyl Thianthrenium Salts in Cross-Coupling Reactions by Copper Catalysis
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Alkyl groups are one of the most widely used groups in organic synthesis. Here, a a series of thianthrenium salts have been synthesized that act as reliable alkylation reagents and readily engage in copper-catalyzed Sonogashira reactions to build C(sp3)?C(sp) bonds under mild photochemical conditions. Diverse alkyl thianthrenium salts, including methyl and disubstituted thianthrenium salts, are employed with great functional breadth, since sensitive Cl, Br, and I atoms, which are poorly tolerated in conventional approaches, are compatible. The generality of the developed alkyl reagents has also been demonstrated in copper-catalyzed Kumada reactions.
- Chen, Cheng,Lu, Hongjian,Shi, Zhuangzhi,Wang, Minyan,Zhao, Binlin
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supporting information
p. 21756 - 21760
(2021/08/30)
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- METHODS FOR FUNCTIONALIZATION HYDROCARBONS
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In one aspect, the disclosure relates to a method for functionalizing hydrocarbons. In a further aspect, the method involves heating a hydrocarbon with a composition having an acid and an oxidant. In other aspects, the composition can further include an iodine-based compound and/or a compound having formula AaXn. In any of these aspects, the oxidant can be regenerated in situ or in a separate regeneration step. Also disclosed are functionalized hydrocarbons produced by the disclosed method. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.
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Paragraph 0200; 0201
(2020/09/27)
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- Water determines the products: An unexpected Br?nsted acid-catalyzed PO-R cleavage of P(iii) esters selectively producing P(O)-H and P(O)-R compounds
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Water is found able to determine the selectivity of Br?nsted acid-catalyzed C-O cleavage reactions of trialkyl phosphites: with water, the reaction quickly takes place at room temperature to afford quantitative yields of H-phosphonates; without water, the reaction selectively affords alkylphosphonates in high yields, providing a novel halide-free alternative to the famous Michaelis-Arbuzov reaction. This method is general as it can be readily extended to phosphonites and phosphinites and a large scale reaction with much lower loading of the catalyst, enabling a simple, efficient, and practical preparation of the corresponding organophosphorus compounds. Experimental findings in control reactions and substrate extension as well as preliminary theoretical calculation of the possible transition states all suggest that the monomolecular mechanism is preferred.
- Li, Chunya,Wang, Qi,Zhang, Jian-Qiu,Ye, Jingjing,Xie, Ju,Xu, Qing,Han, Li-Biao
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supporting information
p. 2916 - 2922
(2019/06/18)
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- Tuning the biological activity of cationic anthraquinone analogues specifically toward Staphylococcus aureus
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Development of new antibacterial agents against drug resistant bacteria is an imminent task, especially against methicillin-resistant Staphylococcus aureus (MRSA). While MRSA can still be treated with broad spectrum antibiotics, the use of which often leads to the disruption of normal microbial flora leading to Clostridium difficile infection (CDI). Herein, a new class of antibacterial agent, cationic anthraquinone analogues specifically against MRSA, has been developed. Through the variation and optimization of substituents, these agents are selective toward MRSA, and not Gram negative bacteria which may avoid the problem of CDI. In addition, newly discovered lead compounds also show significantly reduced cytotoxicity against normal mammalian cells than cancerous cells. This interesting finding can alleviate the toxicity and side effect problems often associate with the use of antibiotics.
- Subedi, Yagya Prasad,Alfindee, Madher N.,Shrestha, Jaya P.,Chang, Cheng-Wei Tom
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p. 683 - 690
(2018/08/23)
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- COMPOUND FOR SPECIFICALLY BINDING TO AMYLOID ?-PROTEIN
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Provided is a compound for specifically binding to amyloid β-protein. The compound has thereon a nuclide with a large thermal neutron capture cross section and the compound is capable of specifically binding to the amyloid β-protein. The property of the compound allows it to be used in conjunction with a neutron capture therapy device to eliminate amyloid β-protein. Similarly, when the compound is labelled with radioactive element 11C, the compound can also be used in conjunction with PET/CT for determining the part of the brain where amyloid β-protein is deposited, for diagnosing Alzheimer's disease. Also disclosed is a preparation process for the compound. The beneficial effect of the present disclosure is to make the therapy and diagnosis of Alzheimer's disease more targeted by providing the compound for specifically binding to amyloid β-protein.
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Paragraph 0080-0083
(2018/11/21)
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- Arylation of diorganochalcogen compounds with diaryliodonium triflates: Metal catalysts are unnecessary
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Diaryliodonium triflates transfer an aryl group to the chalcogen atom of organic sulfides, selenides, and tellurides (but not ethers), in the absence of transition-metal catalyst, simply upon heating in chloroform or dichloroethane solution.
- Racicot, Lanne,Kasahara, Takahito,Ciufolini, Marco A.
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supporting information
p. 6382 - 6385
(2015/02/19)
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- A convenient synthesis of triflate anion ionic liquids and their properties
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A solvent- and halogen-free synthesis of high purity triflate ionic liquids via direct alkylation of organic bases (amines, phosphines or heterocyclic compounds) with methyl and ethyl trifluoromethanesulfonate (methyl and ethyl triflate) has been developed. Cheap and non-toxic dimethyl and diethyl carbonate serve as source for the methyl and ethyl groups in the preparation of methyl and ethyl triflate by this invented process. The properties of ionic liquids containing the triflate anion are determined and discussed.
- Ignat'ev, Nikolai V.,Barthen, Peter,Kucheryna, Andryi,Willner, Helge,Sartori, Peter
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experimental part
p. 5319 - 5338
(2012/08/28)
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- Protonation and alkylation of organophosphorus compounds with trifluoromethanesulfonic acid derivatives
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Protonation (alkylation) of triphenylphosphine, triethylphosphite, triphenylphosphine oxide, triethylphosphate, hexamethylphosporamide, and dimethylphosphite with trifluoromethanesulfonic acid, its bisimide, and methyl ester was studied and the corresponding 1H, 13C, 19F, 31P NMR spectra were analyzed.
- Tolstikova,Bel'Skikh,Shainyan
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experimental part
p. 474 - 480
(2011/06/23)
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- Synthesis of azide-alkyne fragments for 'click' chemical applications. formation of chiral 1,4-disubstituted-(β-alkyl) γ- 1,2,3-triazole scaffolds from orthogonally protected chiral β-alkyl-trialkylsilyl γ- Pentynyl azides and chiral β-alkyl γ- Pentynyl-alcohols
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A library of chiral γ-pentynyl alcohols and γ-pentynyl azides was made using the SuperQuat auxiliary. Coupling of the free alkynes with the azides by Huisgen 1,3-dipolar cycloaddition provided chiral oligomeric 1,4-disubstituted-1,2,3-triazoles as possible peptidomimetic compounds.
- Montagnat, Oliver D.,Lessene, Guillaume,Hughes, Andrew B.
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body text
p. 1541 - 1549
(2011/09/16)
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- α-aminoboronic acids prepared by novel synthetic methods
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The present invention relates to a novel class of α-aminoboronic acids of Formula (V), which are useful as intermediates in synthetic processes for inhibitors of the serine proteases, leukocyte elastase, pancreatic elastase, cathepsin G, and chymotrypsin. More specifically, the α-aminoboronic acids are useful as intermediates for the synthesis of Hepatitis C Virus (HCV) protease inhibitors. This invention also generally relates to novel methods for the preparation of α-aminoboronic acids.
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- Synthesis of chiral pilocarpine analogues via a C-8 ketone intermediate.
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The synthesis of a chiral pilocarpine analogue 3 in which the lactone ring is replaced by an oxazolidinone and the bridging methylene group is in the ketone oxidation state has been accomplished. The utility of this compound as a key intermediate for the preparation of more complex structures was demonstrated by its reduction to two alcohol epimers and its reaction with a methylene ylide.
- Holden, Kenneth G,Mattson, Matthew N,Cha, Kyung Hoi,Rapoport, Henry
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p. 5913 - 5918
(2007/10/03)
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- Synthesis and nucleophilic reactions of cyano substituted N-methoxyisoquinolinium salts
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Starting from isoquinoline, the cyano substituted N-methoxyisoquinolinium salts 1.1 and 1.4 are prepared. Their behaviour in the presence of O-, C- and N-nucleophiles in different aprotic solvents is examined: from the 1-cyano substituted isoquinolinium derivative 1.1, 1- and 3-aminals or 1-iminium salts are obtained depending on the amine used, and N-methoxyisocarbostyril 4.1.1 in H2O and OH-. The reaction of the 4-cyano-N-methoxyisoquinolinium salt 1.4 with amines yields 1-aminals and with OH- the corresponding hemiaminal. Conversion with CN- results in dinitrile derivatives and N-oxides.
- Heber,Holzgrabe,Werra
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p. 785 - 790
(2007/10/02)
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- DISPLACEMENT OF O- VERSUS N-SUBSTITUENTS FROM NITROSAMINE-DERIVED DIAZENIUM IONS BY THREE DIVERGENT MECHANISMS
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Cations formed on O-coordination of N-nitrosodimethylamine with different electrophiles decomposed by different routes: dissociation of Me2N=NOCMe3(1+) ClO4(1-); regeneration of free nitrosamine by nucleophilic cleavage of the O-Si bond in Me2N=NOSiMe3(1+) CF3SO3(1-); and nucleophilic displacement of the N-methyl groups from Me2N=NOSO2CF3(1+) CF3SO3(1-).
- Ohannesian, Lena,Keefer, Larry K.
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p. 2903 - 2906
(2007/10/02)
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- Reactions of the Readily Accessible Electrophile, Trifluoroacetyl Triflate: A Very Reactive Agent for Trifluoroacetylations at Oxygen, Nitrogen, Carbon, or Halogen Centers
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Trifluoroacetyl triflate (TFAT) is readily prepared in 82percent yield by the dehydration (phosphorus pentoxide) of a 2:1 mixture of trifluoroacetic acid and trifluoromethanesulfonic (triflic) acid.Reactions of this highly electrophilic trifluoroacetylating reagent with alcohols, ketones, ethers, amines, and pyridines give esters, enol esters, ether cleavage, amides, and acylpyridinium ions, respectively.Reactions with ionic or easily ionizable alkyl halides give the very volatile trifluoroacetyl halides and the ionic triflate.Triphenylmethyl chloride, for example, is quantitatively converted to triphenylcarbenium triflate in a very convenient synthetic procedure.Trifluoroacetyl triflate is used in the synthesis of the first member of a new class of pyrylium salts, 2,6-dimethoxypyrylium triflate.
- Forbus, T. R.,Taylor, S. L.,Martin, J. C.
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p. 4156 - 4159
(2007/10/02)
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- SYNTHESIS OF TRIFLATE AND CHLORIDE SALTS OF ALKYL N,N-BIS(2,2,2-TRIFLUOROETHYL)AMINES
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Triflate and chloride salts have been prepared in high yield by using the triflate displacement reaction.
- Anderson, Gloria L.,Harruna, Issifu
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p. 111 - 114
(2007/10/02)
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- Onium Ions. 34. The Methoxydiazonium Ion: Preparation, 1H, 13C, and 15N NMR and IR Structural Studies, Theoretical Calculations, and Reaction with Aromatics. Attempted Preparation and the Intermediacy of the Hydroxydiazonium Ion
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Nitrous oxide is methylated with CH3F -> SbF5 in SO2F2 or with CH3O(1+)SOClF in SO2ClF to give the stable methoxydiazonium ion CH3ON2(1+) (1), which was characterized by NMR (15N, 13C, 1H) and FT IR spectroscopic studies.It is stable below -30 deg C, above which it decomposes, regenerating N2O.When reacted with aromatics, such as toluene, 1 gives only methylation products and no methoxy derivatives are formed.Spectroscopic and chemical data indicate that the mesomeric form CH3O-N=N(1+) is a significant contributor to the overall structure of 1.Consideration of computed charge distribution (4-31 G with full geometry optimization and 4-31 G*) also supports this conclusion.Independent generation of 1 was also studied by solvolysis of methylazoxy triflate and diazotization of methoxylamine with NO(1+)BF4(1-).Preparation of the elusive hydroxydiazonium ion HON2(1+) (4) was attempted by protonation of nitrous oxide in superacids, but no long-lived ion could be observed.Diazotization of hydroxylamine with NO(1+)BF4(1-) gives nitrous oxide indicative of the intermediacy of 4.
- Olah, George A.,Herges, Rainer,Laali, Khosrow,Segal, Gerald A.
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p. 2054 - 2057
(2007/10/02)
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- Azodesilylation - a Novel Aprotic Diazotization Technique
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Nitrosyl compounds NOA (4a - e, A = Cl, Br, BF4, CF3SO3, I) - generated partially in situ from O = N - OR/(CH3)3SiA (7a, b, R = iC5H11, C2H5/8a, b, e, A = Cl, Br, I) - react in aprotic organic media with N,N-bissilylated organylamines RN2 (3b, R = C6H5; 15, R = CH3) under generation of diazonium systems R - N2+ A- and formation of non-nucleophilic hexamethyldisiloxane (6b).This method represents the first nucleophile excluding diazotization technique on the basis of three-coordinated nitrogen and is termed "azodesilylation".
- Weiss, Robert,Wagner, Klaus-Georg,Hertel, Marion
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p. 1965 - 1972
(2007/10/02)
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- The Chemistry of Nitrilium Salts. Part 2. The Preparation of Nitrilium Trifluoromethanesulphonate Salts and Their Reactions with Some Oxygen and Sulphur Nucleophiles
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The syntheses of the nitrilium salts NMe>+3SCF3 i, PhCH2, Ph, CH2=CHCH2, NC(CH2)3, and CH2=CH> by reaction of MeO3SCF3 with the corresponding nitriles are described. the similar reaction between (E)-PhCH=CHCN and MeO3SCF3 gives a mixture of NMe>+SCF3 and the s-triazinium salt 3C3N3H>+3SCF3, which hydrolyzes to give (E)-PhCH=CHCONHMe and the triazine.The compound CF3SO3(CH2)4CN, prepared from I(CH2)4CN and AgO3SCF3, does not form a cyclic nitrilium salt, but slowly dimerizes at room temperature to N(CH2)4CN>+3SCF3.Both I(CH2)4CN and CF3SO3(CH2)4CN can be converted into the salt NMe>+3SCF3, but this does not form a dinitrilium salt on reaction with acetonitrile.On heating benzophenone oxime with CF3SO3H Beckmann rearrangement products are obtained, but conversion of +SCF3 into the nitrilium salt NPh>*3SCF3 ocuurs in only low yield even after 8 h at 130 deg C under high vacuum.The nitrilium salts with R = Ph, Me, Pri, and PhCH2 undergo rapid exothermic reaction with phenol, thiophenol, alcohols, and thiols to give the corresponding imidate and thioimidate salts in high yields. 4,4-Dimethy-2-phenyl-1,3-oxazoline is obtained in 74percent yield on heating NMe>+*3SCF3 with H2NCMe2CH2OH, and both this and 2,4,4-trimethyloxazoline react with MeO3SCF3 to give almoust quantitative yields of the corresponding N-methyloxazolinium salts, which can be reduced to the oxazolidines with NaBH4.N-Methyloxazolinium salts have also been obtained from the reactions of nitrilium salts (R = Ph or Me) with ethylene oxide.
- Booth, Brian L.,Jibodu, Kehinde O.,Proenca, M. Fernanda J. R. P.
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p. 1067 - 1073
(2007/10/02)
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- The Reaction of Some Cyclic and Open-chain Disulphides with Methyl Trifluoromethanesulphonate
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The rates of reaction of methyl trifluoromethanesulphonate with a number of cyclic and open-chain disulphides have been studied at various temperatures.The main products of the reactions have been identified as the corresponding methylsulphonium salts.The difference in reactivity between the fivemembered and other disulphides arises from a combination of both enthalpy and entropy effects.
- Ravenscroft, Michael,Roberts, Roger M. G.,Tillett, John G.
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p. 1569 - 1572
(2007/10/02)
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- Alkoxyphosphonium Salts. 3. Kinetics and Thermodynamics in Alkylation by Alkoxyphosphonium Salts
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Several methoxyphosphonium trifluoromethanesulfonates (triflates) are characterized by the rates of methyl transfer to the 2,4-dinitrophenoxide ion.In acetone at 25 deg C, the measured second-order rate constants range from about 0.2 to about 40 M-1s-1, putting substances of this class among the most powerful methylating agents.The methylating power is confirmed by the measurement of the equilibrium extent of methylation of the counterion, the triflate ion.The Arbuzov rearrangement of trimethyl phosphite is slow with the catalyst methyl iodide but is fast enough with the cata lyst methyltrimethoxyphosphonium triflate to allow calorimetric measurement for the conversion of trimethyl phosphite to dimethyl methylphosphonate; ΔH = -24 +/- 2 kcal/mol.An earlier error in the measurement of the rate of this reaction is corrected, so that the mechanism of the methyl iodide catalyzed Arbuzov reaction of trimethyl phosphite is no longer in question; the first step is rate-determining.
- Lewis, Edward S.,Colle, Karla S.
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p. 4369 - 4372
(2007/10/02)
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- Phosphoryl Compounds in Strong Acids. Stability of the P-N Bond and Alkyl-oxygen Cleavage of Phosphoramidates in Trifluoromethanesulfonic acid
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In trifluoromethanesulfonic acid (HTFMS) the P-N bond of (RO)2P(O)NMe2 is stable, but de-O-alkylation is observed; rates of the oxygen-alkyl cleavage of phosphoramidates and some other phosphoryl compounds in HTFMS have been determined.
- Modro, Tomasz A.
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p. 201 - 202
(2007/10/02)
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- Synthesis of 1-Substituted-7-hydroxyquinolinium Salts
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The reaction of 7-acetoxyquinoline with trifluorosulfonate esters of primary alcohols in methylene chloride or acetonitrile, followed by acid hydrolysis, provides a general synthesis of 1-substituted-7-hydroxyquinolines, whose phenolate anions are fluorescent.
- Ranganathan, N.,Storey, B. T.
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p. 1069 - 1072
(2007/10/02)
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