5469-26-1Relevant articles and documents
An NMR, IR and theoretical investigation of the methyl effect on conformational isomerism in 3-fluoro-3-methyl-2-butanone and 1-fluoro-3,3-dimethyl-2-butanone
Tormena, Claudio F.,Rittner, Roberto,Abraham, Raymond J.
, p. 211 - 217 (2002)
The solvent dependence of the 1H and 13C NMR spectra of 3-fluoro-3-methyl-2-butanone (FMB) and 1-fluoro-3,3-dimethyl-2-butanone (FDMB) was examined and the 4JHF, 1JCF and 2JCF couplings are reported. Density functional theory (DFT) at the B3LYP/6-311 ++ G(2df, 2p) level with ZPE (zero point energy) corrections was used to obtain the conformer geometries. In both FMB and FDMB, the DFT method gave only two minima for cis (F - C - C = O, 0°) and trans (F - C - C = O, 180°) rotamers. Assuming the cis and trans forms, the observed couplings in FMB when analysed by solvation theory gave the energy difference Ecis - Etrans of 3.80 kcal mol-1 (1 kcal = 4.184 kJ) in the vapour phase (cf. the DFT value of 3.21 kcal mol-1), decreasing to 2.6 kcal mol-1 in CCl4 and to 0.27 kcal mol-1 in DMSO. In FDMB the observed couplings when analysed similarly by solvation theory gave Ecis - Etrans = 1.80 kcal mol-1 in the vapour phase, decreasing to 0.47 kcal mol-1 in CCl4 and to - 1.25 kcal mol-1 in DMSO. The introduction of a methyl group geminal to the fluorine atom shifts the conformational equilibrium towards the trans rotamer, in contrast to no significant effect when the methyl group is introduced at the α-carbon further from the fluorine atom. Copyright
Base-Catalyzed Intramolecular Defluorination/O-Arylation Reaction for the Synthesis of 3-Fluoro-1,4-oxathiine 4,4-Dioxide
Kang, Lei,Zhang, Jinlong,Yang, Huameng,Qian, Jinlong,Jiang, Gaoxi
supporting information, p. 785 - 789 (2021/04/09)
A novel process involving base-catalyzed intramolecular defluorination/O-arylation of readily available α-fluoro-β-one-sulfones was realized and provided a series of 3-fluoro-1,4-oxathiine 4,4-dioxide derivatives in good to excellent yields. Unlike traditional defluorination reactions with stoichiometric base as the deacid reagent, this process is triggered by a catalytic amount of base (TMG: tetramethylguanidine) and molecular sieves serve as both an adsorbent to remove HF acid and an activator to assist C-F bond cleavage.
Diastereoselective Synthesis of Z-Alkenyl Disulfides from α-Thiophosphorylated Ketones and Thiosulfonates
Musiejuk, Mateusz,Doroszuk, Justyna,J?drzejewski, Bartosz,Ortiz Nieto, Gregory,Marin Navarro, Marisol,Witt, Dariusz
supporting information, p. 618 - 626 (2019/12/24)
We developed a simple and efficient method for the synthesis of functionalized unsymmetrical Z-alkenyl disulfides under mild conditions in moderate to good yields. The designed method is based on the reaction of α-thiophosphorylated carbonyl compounds with thiotosylates in the presence of a base. The developed method allows the preparation of unsymmetrical Z-alkenyl disulfides bearing additional hydroxy, carboxy, or ester functionalities. (Figure presented.).
Nickel-Catalyzed Asymmetric Addition of Aromatic Halides to Ketones: Highly Enantioselective Synthesis of Chiral 2,3-Dihydrobenzofurans Containing a Tertiary Alcohol
Li, Ying,Li, Wendian,Tian, Jiangyan,Huang, Guozheng,Lv, Hui
supporting information, p. 5353 - 5357 (2020/07/14)
A highly enantioselective and straightforward synthetic procedure to chiral 3-hydroxy-2,3-dihydrobenzofurans has been developed by nickel/bisoxazoline-catalyzed intramolecular asymmetric addition of aryl halides to unactivated ketones, giving 2,3-dihydrobenzofurans with a chiral tertiary alcohol at the C-3 position in good yields and excellent enantioselectivities (up to 92percent yield and 98percent ee). The gram-scale reaction also proceeded smoothly without a loss of yield and enantioselectivity.
Atom-economical brominations with tribromide complexes in the presence of oxidants
Yubata, Kotaro,Matsubara, Hiroshi
supporting information, p. 1001 - 1004 (2019/03/13)
Bromination is an important transformation in organic synthesis, and novel efficient bromination techniques are still required. Herein, we demonstrate atom-economical brominations using (DMI)2HBr3, a novel tribromide complex, with oxidants such as DMSO and Oxone. Using this system, olefinic and aromatic brominations, as well as selective α-monobrominations of ketones proceeded well to afford the desired bromides in good yields. Importantly, in these reactions all of the bromine atoms in this complex are used to brominate.
Synthesis and evaluation of various heteroaromatic benzamides as analogues of –ylidene-benzamide cannabinoid type 2 receptor agonists
Moir, Michael,Boyd, Rochelle,Gunosewoyo, Hendra,Montgomery, Andrew P.,Connor, Mark,Kassiou, Michael
supporting information, (2019/08/12)
The CB2 receptor is an attractive target for the treatment of a wide range of diseases and pathological conditions. Compounds that selectively activate the CB2 receptor are desirable as this avoids CB1-mediated psychoactive effects. Heteroarylidene-benzamides have demonstrated efficacy as selective CB2 receptor agonists. We aimed to expand the structure-activity relationship studies of this series of compounds by investigating the heteroaromatic core via the synthesis and in vitro evaluation of a small library of various heteroaromatic benzamide analogues. As heteroaromatic amides are privileged scaffolds in drug design, methods to synthesise them are of interest. Concise and reliable synthetic strategies were developed to access these novel analogues. The –ylidene-benzamide moiety is shown to be essential for CB activity as all amide derivatives exhibit no functional activity at either CB2 or CB1 receptors.
Microwave synthesis of 1-aryl-1H-pyrazole-5-amines
Everson, Nikalet,Yniguez, Kenya,Loop, Lauren,Lazaro, Horacio,Belanger, Briana,Koch, Grant,Bach, Jordan,Manjunath, Aashrita,Schioldager, Ryan,Law, Jarvis,Grabenauer, Megan,Eagon, Scott
supporting information, p. 72 - 74 (2018/11/30)
A microwave-mediated synthesis of 1H-pyrazole-5-amines utilizing 1 M HCl at 150 °C was developed in order to provide products in a matter of minutes with minimal purification. Most reactions are complete in only 10 min and can be isolated via a simple filtration without the need for further purification by column chromatography or recrystallization. This method tolerates a range of functional groups and can be performed on milligram to gram scales.
Preparation of a novel bromine complex and its application in organic synthesis
Nishio, Yuya,Yubata, Kotaro,Wakai, Yutaro,Notsu, Kotaro,Yamamoto, Katsumi,Fujiwara, Hideki,Matsubara, Hiroshi
, p. 1398 - 1405 (2019/02/07)
Although molecular bromine (Br2) is a useful brominating reagent, it is not easy to handle. Herein, we describe the preparation of a novel air-stable bromine complex prepared from 1,3-dimethyl-2-imidazolidinone (DMI) and Br2, which was identified to be (DMI)2HBr3 by spectral and X-ray techniques. This complex was then used to brominate olefins, carbonyl compounds, and aromatics, as well as in the Hofmann rearrangement. Yields of reaction products using this complex were almost the same or superior to those using other bromine alternatives.
O,O,N-ligand trivalent bicyclic phosphide, synthetic method and catalysis application
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Paragraph 0033; 0034; 0035, (2018/07/30)
The invention relates to an O,O,N-ligand trivalent bicyclic phosphide as an organic catalyst, and a chemical structural formula of the above compound is shown as the specification, substituent R1 andR2 can be any one of alkyl or nitro group such as hydrogen or methyl or ethyl or isopropyl or t-butyl, nitro group, cyano group, carbonyl group, and trifluoromethyl group, and the substituent position, number and conjugate position are not fixed. The synthetic method takes conventional ketone as a raw material, the multiple steps of bromination, ammonification, reduction, and cyclisation are carried out, and the O,O,N-ligand trivalent bicyclic phosphide can be finally synthesized. The method is used for synthesizing the O,O,N-ligand trivalent bicyclic phosphide with a novel structure, and provides a novel synthesis route for the type of the phosphor compound, and successfully achieves the effective application of the O,O,N-ligand trivalent bicyclic phosphide, which can effectively catalyzean intermolecular Wittig reaction. The rear O,O,N-ligand trivalent bicyclic phosphide has obvious effect in catalysis of an organic reaction system, can effectively catalyze the intermolecular Wittigreaction, increases the reaction rate, and shortens the reaction time.
N,N,N coordinated trivalent bicyclophosphide, synthetic method and catalytic application thereof
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Paragraph 0039; 0040; 0041; 0042, (2018/07/30)
The invention provides a N,N,N coordinated trivalent bicyclophosphide as an organic catalyst. The chemical structural formula of the compound is shown in the description. The final N,N,N coordinated trivalent bicyclophosphide is synthesized by adopting ketone as a raw material and multiple steps of bromination, ammoniation, reduction, imidization, hydrogenation and cyclization and the like in sequence. The N,N,N coordinated trivalent bicyclophosphide is characterized by synthesis of the N,N,N coordinated trivalent bicyclophosphide with an all-new structure and all-new synthetic route for preparing the phosphorus compound; simultaneously, the effective application of the N,N,N coordinated trivalent bicyclophosphide is successfully obtained, i.e., intramolecular aza Wittig reaction can be effectively catalyzed. Compared with the traditional transitional metal catalyst, the rare N,N,N coordinated trivalent bicyclophosphide has an obvious action in catalyzing an organic reaction system, and provides an all-new idea for the existing organic catalytic reaction. Compared with the traditional phosphine catalyst, the N,N,N coordinated trivalent bicyclophosphide has an obvious action in catalyzing the organic reaction system.
