Tag: M.W=200-250

Vincent, Stephane P. published the artcileElectrophilic Fluorination-Nucleophilic Addition Reaction Mediated by Selectfluor: Mechanistic Studies and New Applications, Application of 1-Fluoropyridiniumtriflate, the publication is Journal of Organic Chemistry (1999), 64(14), 5264-5279, database is CAplus and MEDLINE.

The electrophilic fluorination-nucleophilic addition reaction with Selectfluor-type reagents upon glycals has been studied and optimized. This reaction leads to selective fluorination at the 2-position with concomitant nucleophilic addition to the anomeric center. To understand the stereochem. outcome of this process, a mechanistic study has led to the discovery that, in the fucose series, Selectfluor adds specifically in a syn manner, yielding a 1-[TEDA-CH₂Cl]-2-fluoro saccharide that anomerizes slowly to a more stable intermediate. The anomeric α/β distribution was studied as a function of reactants and conditions, and it was found that a judicious choice of protective group strategy can improve the stereoselectivity of both fluorination and nucleophilic addition Furthermore, a hypersensitive radical probe was used to probe the reaction, and no product characteristic of a radical process was isolated, suggesting that no single electron transfer occurs during the attack of the glycal on Selectfluor. The importance of solvent effect, Selectfluor counterion, and stepwise procedure has also been discussed. This study has brought an important improvement of yields and a broader range of allowed nucleophiles such as secondary alcs. of carbohydrates, amino acids, phosphates, or phosphonates. This optimized process was further applied to the modification of important bioactive mols., including the synthesis of fluorinated daunomycin and oleandrin analogs and the oxidation of thio glycosides to the corresponding sulfoxides.

Journal of Organic Chemistry published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C11H11BFNO4, Application of 1-Fluoropyridiniumtriflate.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Glinkerman, Christopher M. published the artcileSynthesis, Characterization, and Rapid Cycloadditions of 5-Nitro-1,2,3-triazine, COA of Formula: C11H8N2O2, the publication is Organic Letters (2018), 20(9), 2628-2631, database is CAplus and MEDLINE.

The synthesis, characterization, and a study of the cycloaddition reactions of 5-nitro-1,2,3-triazine (I) are reported. The electron-deficient nature of I permits rapid cycloaddition with a variety of electron-rich dienophiles, including amidines, enamines, enol ethers, ynamines, and ketene acetals in high to moderate yields. ¹H NMR studies of a representative cycloaddition reaction between I and an amidine revealed a remarkable reaction rate and efficiency (1 mM, <60 s, CD₃CN, 23°, >95%).

Organic Letters published new progress about 89076-64-2. 89076-64-2 belongs to pyridine-derivatives, auxiliary class Pyridine,Nitro Compound,Benzene, name is 5-Nitro-2-phenylpyridine, and the molecular formula is C11H8N2O2, COA of Formula: C11H8N2O2.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Mallet, Marc published the artcileMigration of lithium in a series of pyridines: double catalysis and reforming. Access to derivatives of 2-bromo-3-lithiopyridine and 4-bromo-2-halo-3-lithiopyridines, Related Products of pyridine-derivatives, the publication is Journal of Organometallic Chemistry (1990), 382(3), 319-32, database is CAplus.

The lithium of an organolithio-pyridinic derivative can be moved from one position to another by an intermol. reaction. Two new reactions are possible for pyridinic organic synthesis; their isomerization of any lithio derivative to a more stable one, and a reaction that transforms a mixture of various bromo-lithio derivatives into a single one. The processes involved and the exptl. tools used are described in terms of the 2-bromo-3-lithio- and 4-bromo-2-halogeno-3-lithiopyridines derivatives synthesis. Thus, 2,6-dibromopyridine was treated with Me₃CLi and (Me₂CH)₂NH in THF followed by DMF to give 40% 2-bromo-3-pyridinecarboxaldehyde.

Journal of Organometallic Chemistry published new progress about 128071-77-2. 128071-77-2 belongs to pyridine-derivatives, auxiliary class Pyridine,Fluoride,Bromide,Aldehyde,Pyridine, name is 4-Bromo-2-fluoronicotinaldehyde, and the molecular formula is C6H3BrFNO, Related Products of pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Banks, R. Eric published the artcileN-Fluoropyridinium trifluoromethanesulfonate and 1-fluoro-2,4,6-trimethoxy-1,3,5-triazinium hexafluoroantimonate: the first experimental determination of the F-N⁺ bond length involving sp² nitrogen, Safety of 1-Fluoropyridiniumtriflate, the publication is Acta Crystallographica, Section C: Crystal Structure Communications (2003), C59(4), m141-m143, database is CAplus and MEDLINE.

The crystal structures of N-fluoropyridinium trifluoromethanesulfonate (I) and 1-fluoro-2,4,6-trimethoxy-1,3,5-triazinium hexafluoroantimonate (II) were determined I is monoclinic, space group P2₁/c, with a 6.027(2), b 12.901(4), c 12.490(3) Å, β 103.96(3)°; Z = 4, d_c = 1.742; R = 0.045, R_w(F²) = 0.149 for 1658 reflections. II is monoclinic, space group P2₁/n, with a 7.616(2), b 11.843(3), c 14.924(3) Å, β 97.43(2)°; Z = 4, d_c = 2.119; R = 0.034, R_w(F²) = 0.071 for 2335 reflections. The N-F bond lengths in I, a known electrophilic fluorinating agent, and its novel analog II are 1.357(4) and 1.354(4) Å, resp.

Acta Crystallographica, Section C: Crystal Structure Communications published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C6H5F4NO3S, Safety of 1-Fluoropyridiniumtriflate.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Storz, Thomas published the artcileThe first practical and efficient one-pot synthesis of 6-substituted 7-azaindoles via a Reissert-Henze reaction, COA of Formula: C14H12N2O, the publication is Synthesis (2008), 201-214, database is CAplus.

A variety of 6-substituted 7-azaindoles (30 examples) were obtained via selective O-methylation of 7-azaindole-N-oxide m-chlorobenzoic acid salt and subsequent, base-catalyzed one-pot reaction with a range of N-, O-, S-nucleophiles or cyanide.

Synthesis published new progress about 1018441-04-7. 1018441-04-7 belongs to pyridine-derivatives, auxiliary class 5.6_Aromatics,Pyrrolo[n,m-x]Pyridine, name is 6-(Benzyloxy)-1H-pyrrolo[2,3-b]pyridine, and the molecular formula is C18H34N4O5S, COA of Formula: C14H12N2O.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Rozatian, Neshat published the artcileEnolization rates control mono- versus di-fluorination of 1,3-dicarbonyl derivatives, Recommanded Product: 1-Fluoropyridiniumtriflate, the publication is Chemical Science (2019), 10(44), 10318-10330, database is CAplus and MEDLINE.

Fluorine-containing 1,3-dicarbonyl derivatives are essential building blocks for drug discovery and manufacture To understand the factors that determine selectivity between mono- and di-fluorination of 1,3-dicarbonyl systems, we have performed kinetic studies of keto-enol tautomerism and fluorination processes. Photoketonization of 1,3-diaryl-1,3-dicarbonyl derivatives and their 2-fluoro analogs is coupled with relaxation kinetics to determine enolization rates. Reaction additives such as water accelerate enolization processes, especially of 2-fluoro-1,3-dicarbonyl systems. Kinetic studies of enol fluorination with Selectfluor and NFSI reveal the quant. effects of 2-fluorination upon enol nucleophilicity towards reagents of markedly different electrophilicity. Our findings have important implications for the synthesis of α,α-difluoroketonic compounds, providing valuable quant. information to aid in the design of fluorination and difluorination reactions.

Chemical Science published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C6H5F4NO3S, Recommanded Product: 1-Fluoropyridiniumtriflate.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Le, Song Thi published the artcileSynthesis of 2-Aryl-5-Nitropyridines by Three-Component Ring Transformation of 3,5-Dinitro-2-Pyridone, SDS of cas: 89076-64-2, the publication is Asian Journal of Organic Chemistry (2014), 3(3), 297-302, database is CAplus.

2-Arylated-5-nitropyridines were efficiently synthesized by a three-component ring transformation of 3,5-dinitro-2-pyridone with aromatic ketones in the presence of ammonium acetate wherein the dinitropyridone served as a synthetic equivalent of an unstable nitromalonaldehyde. 2,8-Diazabicyclo[3.3.1]non-3-ene derivative was formed as a byproduct and was converted into nitropyridines by heating in the presence of ammonium acetate. This exptl. fact implied that the former compound was a kinetically controlled product and the latter was a thermodynamically controlled product because of the aromatization. This eco-friendly method was applicable to various kinds of aryl and (hetero)aryl ketones to afford the corresponding (hetero)arylated pyridines in good to excellent yields.

Asian Journal of Organic Chemistry published new progress about 89076-64-2. 89076-64-2 belongs to pyridine-derivatives, auxiliary class Pyridine,Nitro Compound,Benzene, name is 5-Nitro-2-phenylpyridine, and the molecular formula is C11H8N2O2, SDS of cas: 89076-64-2.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Rozatian, Neshat published the artcileA quantitative reactivity scale for electrophilic fluorinating reagents, Related Products of pyridine-derivatives, the publication is Chemical Science (2018), 9(46), 8692-8702, database is CAplus and MEDLINE.

The N-F reagent was currently determined through empirical experimentation in the absence of quant. values for electrophilicities. An exptl.-determined kinetic reactivity scale for ten N-F fluorinating reagents, including Selectfluor, NFSI, Synfluor and several N-fluoropyridinium salts, in CH₃CN ws reported. The reactivity scale, which covers eight orders of magnitude, employs para-substituted 1,3-diaryl-1,3-dicarbonyl derivatives to measure relative and absolute rate constants The para-substituted 1,3-diaryl-1,3-dicarbonyl scaffold delivers a convenient, sensitive spectrophotometric reporter of reactivity that also led to the discovery of a unique form of tautomeric polymorphism.

Chemical Science published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C6H5F4NO3S, Related Products of pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Law, Robert P. published the artcileDiscovery of Tetrahydroquinoxalines as Bromodomain and Extra-Terminal Domain (BET) Inhibitors with Selectivity for the Second Bromodomain, Quality Control of 844501-00-4, the publication is Journal of Medicinal Chemistry (2018), 61(10), 4317-4334, database is CAplus and MEDLINE.

The bromodomain and extra-terminal domain (BET) family of proteins bind acetylated lysine residues on histone proteins. The four BET bromodomains-BRD2, BRD3, BRD4, and BRDT-each contain two bromodomain modules. BET bromodomain inhibition is a potential therapy for various cancers and immunoinflammatory diseases, but few reported inhibitors show selectivity within the BET family. Inhibitors with selectivity for the first or second bromodomain are desired to aid investigation of the biol. function of these domains. Focused library screening identified a series of tetrahydroquinoxalines with selectivity for the second bromodomains of the BET family (BD2). Structure-guided optimization of the template improved potency, selectivity, and physicochem. properties, culminating in potent BET inhibitors with BD2 selectivity.

Journal of Medicinal Chemistry published new progress about 844501-00-4. 844501-00-4 belongs to pyridine-derivatives, auxiliary class Pyridine,Boronic acid and ester,Amide,Boronic Acids,Boronic acid and ester, name is (1-(tert-Butoxycarbonyl)-1,2,3,6-tetrahydropyridin-4-yl)boronic acid, and the molecular formula is C10H18BNO4, Quality Control of 844501-00-4.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Lopez-Alvarado, Pilar published the artcileA general synthesis of quinoline-2,5,8(1H)-triones via acylation of 2,5-dimethoxyaniline with S-tert-butyl thioacetates by application of the Knorr cyclization, Synthetic Route of 107263-95-6, the publication is Synthesis (1998), 186-194, database is CAplus.

An efficient synthesis of 3- and/or 4-alkylated quinoline-2,5,8(1H)-triones is described. The reaction sequence employed involves Knorr cyclization of 2,5-dimethoxyanilides into 5,8-dimethoxyquinoline systems, followed by oxidative demethylation with (NH₄)₂Ce(NO₃)₆. The starting 2,5-dimethoxyanilides were prepared by chemoselective acylation of 2,5-(MeO)₂C₆H₃NH₂ with a series of β-oxo thioesters obtained by regioselective alkylation of AcCH₂C(O)SCMe₃ at C(2) and/or C(4). The introduction of electrophiles other than alkyl groups at C(2) on AcCH₂C(O)SCMe₃ was also studied.

Synthesis published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C6H5F4NO3S, Synthetic Route of 107263-95-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem