93-04-9Relevant articles and documents
Coal. Kinetics of O-Alkylation
Liotta, Ronald,Brons, Glen
, p. 1735 - 1742 (1981)
The kinetic reactivities of the acidic hydroxyl groups in coal were measured.The chemical action of quaternary ammonium hydroxyde bases in the presence of alkylating agents was used as the probe.Both Illinois No. 6 bituminous and Rawhide subbituminous coals contain aromatic and aliphatic hydroxyls as well as lesser amounts of carboxylic acids.Illinois coal was found to O-alkylate at a faster rate than Rawhide coal.The reactivities of the acidic functional groups in the coals were correlated to the reactivity of acidic groups in model compounds.This was accomplished by both relative and absolute kinetic rate measurements on each coal and a series of model systems.It was discovered that the activation energy associated with the nucleophilic displacement determined the rate of O-alkylation of the coal.Therefore, the rate of the reaction is not limited by mass transport of the chemical reagents into the coal structure.In this sense, O-alkylation of coal is a most unique reaction.
C-H Triflation of BINOL Derivatives Using DIH and TfOH
Nakazawa, Hironobu,Sako, Makoto,Masui, Yu,Kurosaki, Ryo,Yamamoto, Shunya,Kamei, Toshiyuki,Shimada, Toyoshi
, p. 6466 - 6470 (2019)
C-H trifluoromethanesulfonyloxylation (triflation) of 1,1′-bi-2-naphthol (BINOL) derivatives has been established under mild conditions using 1,3-diiodo-5,5-dimethylhydantoin (DIH) and trifluoromethanesulfonic acid (TfOH). Up to eight TfO groups can be introduced in a single operation. The resulting highly oxidized BINOL derivatives can be successfully converted to 8,8′-dihydroxy BINOL and bisnaphthoquinone compounds. Mechanistic studies suggested that C-H triflation occurs in the form of an aromatic substitution reaction via the in situ formation of a radical cation.
Method for reducing aromatic C-N/Cl C/I bond to aromatic-H / D
-
Paragraph 0028, (2021/09/08)
A method of reducing C an aromatic-N C/Cl/I bond to an aromatic-H / D, the process being a stable aromatic quaternary ammonium salt. After addition of the base and the solvent, the aromatic compound or the deuterated aromatic compound can be efficiently prepared by irradiation with visible light or ultraviolet light. The method can efficiently convert stable aromatic-N/I chemical bonds into aromatic-H / D bonds by visible light or ultraviolet light in a cheap and easily available solvent or deuterated solvent without using a catalyst or a transition metal compound C C. The whole production process is green, environment-friendly, low in cost, wide in substrate applicability, high in yield, high in deuterated rate, simple and convenient to operate, free of explosion risk and remarkable in advantage compared with the conventional production process.
Synthesis of Trinuclear Benzimidazole-Fused Hybrid Scaffolds by Transition Metal-Free Tandem C(sp2)?N Bond Formation under Microwave Irradiation
Dao, Pham Duy Quang,Cho, Chan Sik
, p. 4088 - 4098 (2021/06/16)
2-(2-Bromoaryl)- and 2-(2-bromovinyl)benzimidazoles have been coupled and cyclized with 2-methoxy- and 2-aryloxybenzimidazoles as building blocks in the presence of a base under microwave irradiation to give a class of trinuclear N-fused hybrid scaffolds, benzo[4,5]imidazo[1,2-a]benzo[4,5]imidazo[1,2-c]quinazolines and -pyrimidines, respectively, in good yields. 2-(2-Bromoaryl)- and 2-(2-bromovinyl)imidazoles also reacted with 2-methoxybenzimidazoles in the presence of base under microwave irradiation to give a class of trinuclear N-fused hybrid scaffolds, benzo[4,5]imidazo[1,2-a]imidazo[1,2-c]quinazolines and -pyrimidines, respectively, in similar yields. This process seems to proceed via an initial C(sp2)-N coupling by an addition-elimination nucleophilic aromatic substitution (SNAr) and subsequent cyclization accompanied by extrusion of alcohols.
Ruthenium-Catalyzed Dehydrogenation Through an Intermolecular Hydrogen Atom Transfer Mechanism
Huang, Lin,Bismuto, Alessandro,Rath, Simon A.,Trapp, Nils,Morandi, Bill
supporting information, p. 7290 - 7296 (2021/03/01)
The direct dehydrogenation of alkanes is among the most efficient ways to access valuable alkene products. Although several catalysts have been designed to promote this transformation, they have unfortunately found limited applications in fine chemical synthesis. Here, we report a conceptually novel strategy for the catalytic, intermolecular dehydrogenation of alkanes using a ruthenium catalyst. The combination of a redox-active ligand and a sterically hindered aryl radical intermediate has unleashed this novel strategy. Importantly, mechanistic investigations have been performed to provide a conceptual framework for the further development of this new catalytic dehydrogenation system.