Category: 1268520-92-8

Li, Weipeng published the artcileCooperative Au/Ag Dual-Catalyzed Cross-Dehydrogenative Biaryl Coupling: Reaction Development and Mechanistic Insight, Category: pyrazoles-derivatives, the publication is Journal of the American Chemical Society (2019), 141(7), 3187-3197, database is CAplus and MEDLINE.

In the presence of (Me₂S)AuCl and AgOAc, pyrazoles such as 1-phenylpyrazole underwent chemoselective and regioselective oxidative dehydrogenative coupling reactions with fluorinated arenes and pyridines such as 2,3,5,6-tetrafluoropyridine mediated by PhI(OAc)₂ in 1,4-dioxane to yield (fluoroaryl)pyrazoles such as I. The mechanism of the oxidative coupling reaction was studied by determination of the reaction kinetics, kinetic isotope effects, and deuterium exchange, by generation and preparation of gold and silver complexes as potential intermediates, and by DFT calculations of transition state structures and energies for arene metalation, transmetalation, and reductive elimination reactions. Silver acetate is determined to be is the actual catalyst for C-H activation of electron-poor arenes, rather than gold(I) complexes. A mechanism of gold/silver dual catalysis is proposed, in which silver is responsible for the activation of electron-poor fluoroarenes via a concerted metalation-deprotonation pathway, and gold is responsible for the activation of electron-rich pyrazoles via an electrophilic aromatic substitution process. Kinetic studies reveal that C-H activation of pyrazoles by fluoroarylgold complexes is most likely the rate-limiting step.

Journal of the American Chemical Society published new progress about 1268520-92-8. 1268520-92-8 belongs to pyrazoles-derivatives, auxiliary class Other Aromatic Heterocyclic,Chloride, name is 4-Chloro-1-methyl-1H-pyrazolo[3,4-b]pyridine, and the molecular formula is C7H6ClN3, Category: pyrazoles-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Bookser, Brett C. published the artcileSolvent-Controlled, Site-Selective N-Alkylation Reactions of Azolo-Fused Ring Heterocycles at N1-, N2-, and N3-Positions, Including Pyrazolo[3,4-d]pyrimidines, Purines, [1,2,3]Triazolo[4,5]pyridines, and Related Deaza-Compounds, Application In Synthesis of 1268520-92-8, the publication is Journal of Organic Chemistry (2018), 83(12), 6334-6353, database is CAplus and MEDLINE.

Alkylation of 4-methoxy-1H-pyrazolo[3,4-d]pyrimidine (1b) with iodomethane in THF using NaHMDS as base selectively provided N2-Me product 4-methoxy-2-methyl-2H-pyrazolo[3,4-d]pyrimidine (3b) in an 8/1 ratio over N1-Me product (2b). Interestingly, conducting the reaction in DMSO reversed selectivity to provide a 4/1 ratio of N1/N2 methylated products. Crystal structures of product 3b with N1 and N7 coordinated to sodium indicated a potential role for the latter reinforcing the N2-selectivity. Limits of selectivity were tested with 26 heterocycles which revealed that N7 was a controlling element directing alkylations to favor N2 for pyrazolo- and N3 for imidazo- and triazolo-fused ring heterocycles when conducted in THF. Use of ¹H-detected pulsed field gradient-stimulated echo (PFG-STE) NMR defined the mol. weights of ionic reactive complexes. This data and DFT charge distribution calculations suggest close ion pairs (CIPs) or tight ion pairs (TIPs) control alkylation selectivity in THF and solvent-separated ion pairs (SIPs) are the reactive species in DMSO.

Journal of Organic Chemistry published new progress about 1268520-92-8. 1268520-92-8 belongs to pyrazoles-derivatives, auxiliary class Other Aromatic Heterocyclic,Chloride, name is 4-Chloro-1-methyl-1H-pyrazolo[3,4-b]pyridine, and the molecular formula is C7H6ClN3, Application In Synthesis of 1268520-92-8.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Sakai, Holt A. published the artcileCross-Electrophile Coupling of Unactivated Alkyl Chlorides, Recommanded Product: 4-Chloro-1-methyl-1H-pyrazolo[3,4-b]pyridine, the publication is Journal of the American Chemical Society (2020), 142(27), 11691-11697, database is CAplus and MEDLINE.

Overcoming intrinsic limitations of C(sp³)-Cl bond activation, the development of a novel organosilane reagent Si(TMS)₃(N)R¹R² (R¹ = adamantyl, tert-Bu, i-Pr, n-Bu; R² = H) that can participate in chlorine atom abstraction under mild photocatalytic conditions were reported. In particular, the application of this mechanism to a dual nickel/photoredox catalytic protocol that enables the first cross-electrophile coupling of unactivated alkyl chlorides R³Cl (R³ = cyclohexyl, oxan-4-yl, 4-cyanobutyl, etc.) and aryl chlorides R⁴Cl (R⁴ = pyridin-4-yl, quinolin-3-yl, 2-(methylsulfanyl)pyrimidin-5-yl, etc.) was described. Employing these low-toxicity, abundant, and com. available organochloride building blocks, this methodol. allows access to a broad array of highly functionalized C(sp₂)-C(sp₃) coupled adducts, e.g., I including numerous drug analogs.

Journal of the American Chemical Society published new progress about 1268520-92-8. 1268520-92-8 belongs to pyrazoles-derivatives, auxiliary class Other Aromatic Heterocyclic,Chloride, name is 4-Chloro-1-methyl-1H-pyrazolo[3,4-b]pyridine, and the molecular formula is C7H6ClN3, Recommanded Product: 4-Chloro-1-methyl-1H-pyrazolo[3,4-b]pyridine.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics