19190-80-8Relevant articles and documents
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.
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.
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.
