27729-98-2Relevant academic research and scientific papers
Organocatalytic Enantioselective γ-Elimination: Applications in the Preparation of Chiral Peroxides and Epoxides
Chen, Zhili,Gong, Xiangnan,Hu, Fangli,Huang, Shengli,Jia, Shiqi,Qin, Wenling,Tan, Yu,Xu, Da,Yan, Hailong
, p. 1934 - 1940 (2020/03/24)
An organocatalyzed enantioselective γ-elimination process has been achieved and applied in the kinetic resolution of peroxides to access chiral peroxides and epoxides. The reaction provided a pathway for the preparation of two useful synthetic and biologically important structural motifs through a single-step reaction. A range of substrates has been resolved with a selectivity factor up to 63. The obtained enantioenriched peroxides and epoxides allowed a series of transformations with retained optical purities.
Synthesis and characterization of 1,3,5-triarylpyrazol-4-ols and 3,5-diarylisoxazol-4-ols from chalcones and theoretical studies of the stability of pyrazol-4-ol toward acid dehydration
Cipagauta Esquivel, Edna Carolina,Rufino, Virgínia Camila,Trindade Nogueira, Matheus Henrique,Carbonaro Souza, Ana Carolina,Pliego Júnior, Josefredo Rodriguez,Valle, Marcelo Siqueira
, (2019/12/23)
The synthesis of diverse pyrazol-4-ol and isoxazole-4-ol heterocycles involving only 3 reaction steps is reported in this study. However, the synthesis of carboxamide pyrazol-4-ol has failed in the conditions used in the synthesis, acid methanol solution. The carboxamide pyrazol-4-ol decomposes via dehydration, forming the respective pyrazol. Theoretical calculations were used to elucidate the dehydration reaction. We have found a mechanism for acid-catalyzed dehydration that can explain the experimental observations. The calculated free energy profile for acid-catalyzed dehydration of the carboxamide pyrazol-4-ol and phenylpyrazole-4-ol point out that the latter is more stable in relation dehydration, with a dehydration rate 100 times smaller in acid methanol solution.
Highly Enantioselective Epoxidation of α,β-Unsaturated Ketones Using Amide-Based Cinchona Alkaloids as Hybrid Phase-Transfer Catalysts
Jurczak, Janusz,Majdecki, Maciej,Tyszka-Gumkowska, Agata
supporting information, (2020/11/13)
A series of 20 one chiral epoxides were obtained with excellent yields (up to 99%) and enantioselectivities (up to >99% ee) using hybrid amide-based Cinchona alkaloids. Our method is characterized by low catalyst loading (0.5 mol %) and short reaction times. Moreover, the epoxidation process can be carried out in 10 cycles, without further catalyst addition to the reaction mixture. This methodology significantly enhance the scale of the process using very low catalyst loading.
One approach to cyclic carbonates via a three-component cyclization of phenacyl bromide, CO2, and aldehyde
Yan, Peng,Tan, Xueqin,Jing, Huanwang,Duan, Shuhui,Wang, Xiaoxuan,Liu, Zhongli
experimental part, p. 2459 - 2464 (2011/05/14)
A three-component cyclization reaction was designed for synthesizing cyclic carbonates in a single operation from phenacyl bromide, CO2, and aldehyde in the presence of lithium diisopropylamide (LDA). These novel reactions were achieved under extremely mild conditions to generate the target products in moderate to good yields within 10 min.
IBX-I2 redox couple for facile generation of IOH and I +: Expedient protocol for iodohydroxylation of olefins and iodination of aromatics
Moorthy, Jarugu Narasimha,Senapati, Kalyan,Kumar, Sarvesh
supporting information; experimental part, p. 6287 - 6290 (2009/12/08)
(Chemical Equation Presented) IBX is readily reduced to IBAin the presence of molecular iodine in DMSO to generate hypoiodous acid (IOH), which reacts with a variety of olefins as well as R, β-unsaturated ketones leading to their respective iodohydrins with anti stereochemistry. The same redox chemistry in acetonitrile containing TFA produces iodonium ions for facile iodination of a variety of aromatic compounds in respectable isolated yields.
Monoamine oxidase isoform-dependent tautomeric influence in the recognition of 3,5-diaryl pyrazole inhibitors
Chimenti, Franco,Fioravanti, Rossella,Bolasco, Adriana,Manna, Fedele,Chimenti, Paola,Secci, Daniela,Befani, Olivia,Turini, Paola,Ortuso, Francesco,Alcaro, Stefano
, p. 425 - 428 (2007/10/03)
A series of 3,5-diaryl pyrazoles were prepared and assayed for their ability to inhibit reversibly monoamine oxidase-A (MAO-A) and monoamine oxidase B (MAO-B). Several compounds show inhibitory activity with concentration values in the nanomolar range. A computational work was carried out on the two most selective inhibitors that have tautomeric pyrazole forms. The binding free energies of these compounds for each MAO isoform were influenced by the tautomeric equilibria.
Triphase catalysis in epoxidation of α,β-enones with polymer bound quaternary ammonium salt
Anand, R. Vijaya,Singh, Vinod K.
, p. 807 - 808 (2007/10/03)
A polymer bound quaternary ammonium salt, prepared from DABCO and Merrifield resin, catalyzed an epoxidation of a variety of α,β-enones with aqueous H2O2.
