19190-80-8Relevant articles and documents
Epoxidation of Alkenes with Molecular Oxygen as the Oxidant in the Presence of Nano-Al 2O 3
Zhou, Xuan,Wang, Qiong,Xiong, Wenfang,Wang, Lu,Ye, Rongkai,Xiang, Ge,Qi, Chaorong,Hu, Jianqiang
supporting information, p. 1789 - 1794 (2020/09/18)
The nano-Al 2O 3-promoted epoxidation of alkenes with molecular oxygen as the oxidant has been developed, providing an efficient route to a variety of epoxides in moderate to excellent yields. The environmentally friendly and efficient nano-Al 2O 3catalyst could be easily recovered and reused five times without significant loss of activity.
Regioselective syntheses of 3-hydroxy-4-aryl-3,4,5-trihydro-2H-benzo[b][1,4]diazepin-2(1H)-ones and 3-benzylquinoxalin-2(1H)-ones from arylglycidates when exposed to 1,2-diaminobenzenes
Mamedov, Vakhid A.,Mamedova, Vera L.,Syakaev, Victor V.,Voronina, Julia K.,Mahrous, Essam M.,Korshin, Dmitry E.,Latypov, Shamil K.,Sinyashin, Oleg G.
, (2020/09/10)
Representatives of two pharmacologically significant classes of compounds – 3-hydroxy-4-aryl-3,4,5-trihydro-2H-benzo[b][1,4]diazepin-2(1H)-ones and 3-benzylquinoxalin-2(1H)-ones – obtained in reactions of 1,2-diaminobenzenes with methyl 3-arylglycidates in boiling acetic acid. Substituents in arylglycidates determine the direction of processes. Electron withdrawing substituents (NO2), halogen atoms (Cl, Br, F), as well as the absence of substituents, provide the formation of benzo[b][1,4]diazepin-2(1H)-one derivatives, and electron donating groups (OMe, Me) contribute to the formation of 3-benzylquinoxalin-2(1H)-ones. As a result, a new rare representatives of 3-hydroxy-4-aryl-3,4,5-trihydro-2H-benzo[b][1,4]diazepin-2(1H)-ones were obtained and a new method for producing 3-benzylquinoxalin-2(1H)-ones has been proposed.
SO2F2-Mediated Epoxidation of Olefins with Hydrogen Peroxide
Ai, Chengmei,Zhu, Fuyuan,Wang, Yanmei,Yan, Zhaohua,Lin, Sen
, p. 11928 - 11934 (2019/10/02)
An inexpensive, mild, and highly efficient epoxidation protocol has been developed involving bubbling SO2F2 gas into a solution of olefin, 30% aqueous hydrogen peroxide, and 4 N aqueous potassium carbonate in 1,4-dioxane at room temperature for 1 h with the formation of the corresponding epoxides in good to excellent yields. The novel SO2F2/H2O2/K2CO3 epoxidizing system is suitable to a variety of olefinic substrates including electron-rich and electron-deficient ones.
Enantiomeric resolution, thermodynamic parameters, and modeling of clausenamidone and neoclausenamidone on polysaccharide-based chiral stationary phases
Luo, Xuna,Fang, Chengqiao,Mi, Junru,Xu, Jingzi,Lin, Hansen
, p. 423 - 433 (2019/05/07)
The aim of the paper is to describe a new synthesis route to obtain synthetic optically active clausenamidone and neoclausenamidone and then use high-performance liquid chromatography (HPLC) to determine the optical purities of these isomers. In the process, we investigated the different chromatographic conditions so as to provide the best separation method. At the same time, a thermodynamic study and molecular simulations were also carried out to validate the experimental results; a brief probe into the separation mechanism was also performed. Two chiral stationary phases (CSPs) were compared with separate the enantiomers. Elution was conducted in the organic mode with n-hexane and iso-propanol (IPA) (80/20?v/v) as the mobile phases; the enantiomeric excess (ee) values of the synthetic R-clausenamidone and S-clausenamidone and R-neoclausenamidone and S- neoclausenamidone were higher than 99.9%, and the enantiomeric ratio (er) values of these isomers were 100:0. Enantioselectivity and resolution (α and Rs, respectively) levels with values ranging from 1.03 to 1.99 and from 1.54 to 17.51, respectively, were achieved. The limits of detection and quantitation were 3.6 to 12.0 and 12.0 to 40.0 ug/mL, respectively. In addition, the thermodynamics study showed that the result of the mechanism of chiral separation was enthalpically controlled at a temperature ranging from 288.15 to 308.15?K. Furthermore, docking modeling showed that the hydrogen bonds and π-π interactions were the major forces for chiral separation. The present chiral HPLC method will be used for the enantiomeric resolution of the clausenamidone derivatives.
Controlling Selectivity in Alkene Oxidation: Anion Driven Epoxidation or Dihydroxylation Catalysed by [Iron(III)(Pyridine-Containing Ligand)] Complexes
Tseberlidis, Giorgio,Demonti, Luca,Pirovano, Valentina,Scavini, Marco,Cappelli, Serena,Rizzato, Silvia,Vicente, Rubén,Caselli, Alessandro
, p. 4907 - 4915 (2019/08/30)
A highly reactive and selective catalytic system comprising Fe(III) and macrocyclic pyridine-containing ligands (Pc-L) for alkene oxidation by using hydrogen peroxide is reported herein. Four new stable iron(III) complexes have been isolated and characterized. Importantly, depending on the anion of the iron(III) metal complex employed as catalyst, a completely reversed selectivity was observed. When X=OTf, a selective dihydroxylation reaction took place. On the other hand, employing X=Cl resulted in the epoxide as the major product. The reaction proved to be quite general, tolerating aromatic and aliphatic alkenes as well as internal or terminal double bonds and both epoxides and diol products were obtained in good yields with good to excellent selectivities (up to 93 % isolated yield and d.r.=99 : 1). The catalytic system proved its robustness by performing several catalytic cycles, without observing catalyst deactivation. The use of acetone as a solvent and hydrogen peroxide as terminal oxidant renders this catalytic system appealing.
An Isolable and Bench-Stable Epoxidizing Reagent Based on Triazine: Triazox
Yamada, Kohei,Igarashi, Yuki,Betsuyaku, Tatsuki,Kitamura, Masanori,Hirata, Koki,Hioki, Kazuhito,Kunishima, Munetaka
supporting information, p. 2015 - 2019 (2018/04/16)
A new triazine-based oxidizing reagent, 2-hydroperoxy-4,6-diphenyl-1,3,5-triazine (Triazox), has been developed. The reagent can be synthesized from inexpensive starting materials and is a bench-stable solid that is isolable in pure form. Epoxidation of alkenes possessing acid-sensitive functionalities using Triazox proceeded in good to excellent yields. The accompanying nonacidic triazinone coproduct can be easily removed by filtration. These features indicate that Triazox is a practically useful oxidizing reagent.
New organic-inorganic LDH composites: Synthesis, characterization and catalytic behavior in the green epoxidation of α, β-unsaturated esters
Candu, Natalia,Paul, Diana,Marcu, Ioan-Cezar,Tudorache, Madalina,Parvulescu, Vasile I.,Coman, Simona M.
, p. 127 - 132 (2017/10/05)
New organic-inorganic based LDH composites have been prepared using different methodologies, ie the ion-exchange method (Org@LDH-exch), the reconstruction (Org@LDH-mem) and the direct intercalation (Org@LDH-inter) method, respectively. Irrespective of the procedure, the –C[dbnd]O group of levulinate moiety was envisaged as a potential active organocatalyst in the epoxidation of trans-methylcinnamate to methyl-phenyl-glycidate. The characterisation of these materials through adsorption-desorption isotherms of nitrogen at ?196 °C, XRD, TG-DTA and DRIFT confirmed a successful intercalation only for Org@LDH-inter. The reactions were carried out via in situ generated dioxiranes using levulinate as active organocatalyst and H2O2/acetonitrile mixture as oxidant. Intercalated levulinate in aminoterephthalate/LDH structure led to conversions up to 25% with a total selectivity to methyl-phenyl-glycidate. Besides this, the heterogeneous organocatalyst behave as a green system: the constitutive levulinic acid represents one of the most important renewable platform molecules, while replacing the Oxone reagent with the more benign hydrogen peroxide and the substitution of an inorganic soluble base with the basic function of the LDH-support afford a more benign system.
Dynamic kinetic asymmetric transformations of β-halo-α-keto esters by N,N′-dioxide/Ni(II)-catalyzed carbonyl-ene reaction
Liu, Wen,Cao, Weidi,Hu, Haipeng,Lin, Lili,Feng, Xiaoming
supporting information, p. 8901 - 8904 (2018/08/17)
Dynamic kinetic asymmetric transformations of racemic β-halo-α-keto esters through carbonyl-ene reaction were realized using a chiral N,N′-dioxide-nickel(ii) complex, giving the corresponding β-halo-α-hydroxy esters containing two vicinal chiral tri- and tetrasubstituted carbon centers in good yields and dr with excellent ee values without the use of extra bases. Meanwhile, a proposed reaction mechanism was presented according to the configuration of the product.
Metal-Free and Efficient Epoxidation of α,β-Unsaturated Ketones with 1,1,2,2-Tetrahydroperoxy-1,2-Diphenylethane as a Powerful Solid Oxidant
Khosravi, Kaveh,Naserifar, Shirin,Mahmoudi, Boshra
, p. 683 - 689 (2017/06/19)
1,1,2,2-Tetrahydroperoxy-1,2-diphenylethane was used for the efficient and metal-free epoxidation of various α,β-unsaturated ketones, carried out under mild alkaline conditions at room temperature.
Reductive activation of O2 by a bioinspired Fe complex for catalytic epoxidation reactions
Singh, Kundan K.,Gupta, Sayam Sen
supporting information, p. 5914 - 5917 (2017/07/11)
Aerobic epoxidation of olefins catalyzed by iron complexes without the use of a sacrificial coreductant is unknown. We report the reductive activation of O2 by a bioinspired [(bTAML)FeIII(H2O)]- (1) complex to catalyze the epoxidation of alkenes with TONs of up to 80. Spectroscopic and kinetic evidence indicates the involvement of FeV(O) as the active oxidant during the reaction.
