1629-75-0Relevant academic research and scientific papers
Mechanism of the CuII-catalyzed benzylic oxygenation of (aryl)(heteroaryl)methanes with oxygen
Sterckx, Hans,De Houwer, Johan,Mensch, Carl,Caretti, Ignacio,Tehrani, Kourosch Abbaspour,Herrebout, Wouter A.,Van Doorslaer, Sabine,Maes, Bert U. W.
, p. 346 - 357 (2016)
A mechanistic study of the copper-catalyzed oxidation of the methylene group of aryl(di)azinylmethanes was performed. Initial reaction rates were measured making use of in situ IR reaction monitoring and a kinetic analysis of the reaction was executed. The reaction proved to be first order in oxygen concentration. For substrate and acid concentration, saturation kinetics due to O2 mass transfer limitation were observed. The occurrence of mass transfer limitation was further confirmed by examining the effect of the stirring rate on the initial reaction rate. Interestingly, the effect of the concentration of the catalyst on the rate shows that higher loadings result in a maximal initial rate, followed initially by a steady decrease and subsequently a rate plateau when the concentration is increased further. Mass transfer limitation and increased concentration of dinuclear catalytically active species rationalizes this hitherto unprecedented rate behavior. Continuous-wave and pulsed electron paramagnetic resonance methods were used to characterize the catalytic species present in the solution during the reaction and confirmed the presence of both mono- and dinuclear copper species. Analysis of a diverse substrate scope points towards imine-enamine tautomerization as a crucial process in the oxidation reaction. DFT calculations of these equilibrium constants (pKeq) provided us with a qualitative tool to predict whether or not a substrate is viable for oxidation under the reaction conditions developed.
Silver-Assisted Oxidative Isocyanide Insertion of Ethers: A Direct Approach to β-Carbonyl α-Iminonitriles
Zhao, Leiyang,Liu, Bingxin,Tan, Qitao,Ding, Chang-Hua,Xu, Bin
, p. 9223 - 9227 (2019)
An efficient silver-assisted oxidative coupling of simple ethers with tert-butyl isocyanide was realized in the presence of DDQ. The direct synthesis of high density functional β-carbonyl α-iminonitriles was achieved in a single step with high yields through the synergetic cascade isocyanide insertion into C(sp3)-H bond, where the isocyanide was used as crucial "CN" and "C=N" sources and the tert-butoxyl group acted as the carbonyl source. Diverse reactivity of β-carbonyl α-iminonitriles has been demonstrated.
S 8-Mediated Cyclization of Bis(2-aminophenyl) Disulfide/Diselenide with Arylacetylenes/Styrenes: Access to 2-(Arylmethyl)-1,3-benzothiazoles/benzoselenazoles
Gan, Haifeng,Feng, Caojian,Zhao, Lihuan,Cao, Mengru,Wu, Hongli
, p. 70 - 75 (2021/11/17)
A novel S8-mediated approach to benzothiazoles/benzoselenazoles from bis(2-aminophenyl) disulfides/diselenides and phenylacetylenes or styrenes has been developed. 2-(Arylmethyl)-1,3-benzoselenazoles were comprehensively synthesized for the first time. The reactions proceeded in moderate to excellent yields, and with a gramscale application.
A Novel PIFA/KOH Promoted Approach to Synthesize C2-arylacylated Benzothiazoles as Potential Drug Scaffolds
Hu, Zhi-Gang,Huang, Zhen,Sun, Xiao-Tong,Weng, Jian-Quan,Zhou, Ling-Li
, (2022/01/31)
To discover an efficient and convenient method to synthesize C2-arylacylated benzothiazoles as potential drug scaffolds, a novel [bis(trifluoroacetoxy)iodo]benzene(PIFA)/KOH synergistically promoted direct ring-opening C2-arylacylation reaction of 2H-benz
Benzoheterocyclic Oxime Carbamates Active against Mycobacterium tuberculosis: Synthesis, Structure-Activity Relationship, Metabolism, and Biology Triaging
Van Der Westhuyzen, Renier,Mabhula, Amanda,Njaria, Paul M.,Müller, Rudolf,Ngumbu Muhunga, Denis,Taylor, Dale,Lawrence, Nina,Njoroge, Mathew,Brunschwig, Christel,Moosa, Atica,Singh, Vinayak,Rao, Srinivasa P.S.,Manjunatha, Ujjini H.,Smith, Paul W.,Warner, Digby F.,Street, Leslie J.,Chibale, Kelly
supporting information, p. 9444 - 9457 (2021/07/19)
Screening of a library of small polar molecules against Mycobacterium tuberculosis (Mtb) led to the identification of a potent benzoheterocyclic oxime carbamate hit series. This series was subjected to medicinal chemistry progression underpinned by structure-activity relationship studies toward identifying a compound for proof-of-concept studies and defining a lead optimization strategy. Carbamate and free oxime frontrunner compounds with good stability in liver microsomes and no hERG channel inhibition liability were identified and evaluated in vivo for pharmacokinetic properties. Mtb-mediated permeation and metabolism studies revealed that the carbamates were acting as prodrugs. Toward mechanism of action elucidation, selected compounds were tested in biology triage assays to assess their activity against known promiscuous targets. Taken together, these data suggest a novel yet unknown mode of action for these antitubercular hits.
Photoinduced remote heteroaryl migration accompanied by cyanoalkylacylation in continuous flow
Duan, Xiu,Guo, Kai,Liu, Jie,Ma, Can-Liang,Qin, Long-Zhou,Qiu, Jiang-Kai,Sun, Qi,Wu, Meng-Yu,Yuan, Xin,Zhang, Xin-Peng,Zhu, Shan-Shan
supporting information, p. 8916 - 8921 (2021/11/27)
A photoinduced 1,4-heteroaryl migration from a carbon center to a nitrogen center accompanied by a cyanoalkylacylation of heterocyclic-substituted azidyl homoallylic alcohols and cycloketone oxime esters has been described. This simple and powerful protoc
One-pot synthesis of 2-acylbenzothiazoles from 2-aminobenzenethiols and arylacetonitriles via cyclization and sequential oxidation
Zhang, Shanshan,Wang, Shiwei,Leng, Yuting,Wu, Yangjie
, (2021/08/13)
An efficient one-pot method to access 2-acylbenzothiazoles via AlCl3-mediated cyclization reaction and I2-promoted sequential oxidation reaction of 2-aminobenzenethiols with arylacetonitriles was developed. This reaction proceeds smoothly with a wide range of arylacetonitriles containing different functional groups to give the corresponding products in moderate to good yields under mild conditions. Moreover, this reaction was conveniently conducted on a gram scale, and the yield is still up to 68%.
Visible-light-promoted photocatalyst-free alkylation and acylation of benzothiazoles
Jiang, Pengxing,Liu, Li,Tan, Jiajing,Du, Hongguang
supporting information, p. 4487 - 4491 (2021/05/31)
Herein we report a protocol for the visible-light-mediated alkylation/acylation reaction of benzothiazoles. Alkyl/acyl substituted Hantzsch esters are easily prepared and rationally used as radical precursors. In the presence of BF3·Et2O and Na2S2O8, various benzothiazole derivatives were readily obtained in good yields. Our user-friendly protocol can proceed by simple irradiation with blue LEDs (λ = 465 nm) and without the assistance of external photocatalysts. The reaction is also characterized by mild conditions and scalability, thus offering an alternative and efficient tool for the synthesis of 2-functionalized benzothiazoles.
K2S2O8activation by glucose at room temperature for the synthesis and functionalization of heterocycles in water
Hunjan, Mandeep Kaur,Laha, Joydev K.
, p. 8437 - 8440 (2021/09/02)
While persulfate activation at room temperature using glucose has primarily been focused on kinetic studies of the sulfate radical anion, the utilization of this protocol in organic synthesis is rarely demonstrated. We reinvestigated selected K2S2O8-mediated known organic reactions that invariably require higher temperatures and an organic solvent. A diverse, mild functionalization and synthesis of heterocycles using the inexpensive oxidant K2S2O8 in water at room temperature is reported, demonstrating the sustainability and broad scope of the method. Unlike traditional methods used for persulfate activation, the current method uses naturally abundant glucose as a K2S2O8 activator, avoiding the use of higher temperature, UV light, transition metals or bases.
Photo-redox catalyzed dehydrazinative acylation of N-heterocycles: Via Minisci reaction
Hafeez, Saira,Saeed, Aamer
, p. 38683 - 38689 (2021/12/20)
Visible light-induced acylation of heteroaromatic compounds have been achieved using benzoyl hydrazides as an efficient acyl source under mild reaction conditions. The photo-redox catalyzed oxidative cleavage of hydrazides leads to in situ formation of ac
