583-60-8Relevant articles and documents
Activation of hydrogen peroxide by ionic liquids: Mechanistic studies and application in the epoxidation of olefins
Markovits, Iulius I. E.,Eger, Wilhelm A.,Yue, Shuang,Cokoja, Mirza,Muenchmeyer, Christian J.,Zhang, Bo,Zhou, Ming-Dong,Genest, Alexander,Mink, Janos,Zang, Shu-Liang,Roesch, Notker,Kuehn, Fritz E.
, p. 5972 - 5979 (2013)
Imidazolium-based ionic liquids that contain perrhenate anions are very efficient reaction media for the epoxidation of olefins with H2O 2 as an oxidant, thus affording cyclooctene in almost quantitative yields. The mechanism of this reaction does not follow the usual pathway through peroxo complexes, as is the case with long-known molecular transition-metal catalysts. By using in situ Raman, FTIR, and NMR spectroscopy and DFT calculations, we have shown that the formation of hydrogen bonds between the oxidant and perrhenate activates the oxidant, thereby leading to the transfer of an oxygen atom onto the olefin demonstrating the special features of an ionic liquid as a reaction environment. The influence of the imidazolium cation and the oxidant (aqueous H2O2, urea hydrogen peroxide, and tert-butyl hydrogen peroxide) on the efficiency of the epoxidation of cis-cyclooctene were examined. Other olefinic substrates were also used in this study and they exhibited good yields of the corresponding epoxides. This report shows the potential of using simple complexes or salts for the activation of hydrogen peroxide, owing to the interactions between the solvent medium and the active complex. Copyright
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Takagi et al.
, p. 214 (1968)
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Two new silver(I) complexes with 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz): Preparation, characterization, crystal structure and alcohol oxidation activity in the presence of oxone
Najafpour, Mohammad Mahdi,Ho?yn?ska, Ma?gorzata,Amini, Mojtaba,Kazemi, Sayed Habib,Lis, Tadeusz,Bagherzadeh, Mojtaba
, p. 2837 - 2843 (2010)
Two new silver(I) complexes ((tptz)Ag2(NO3) 2 and [Ag5(tptz)4](NO3)5) with 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) have been synthesized and characterized by X-ray diffraction, elemental analysis, 1H NMR, IR, fluorescence, UV-Vis spectroscopy and electrochemistry. Oxidation of alcohols to their corresponding aldehydes and ketones was conducted with one of the Ag complexes as a catalyst, soluble enough in organic solvent, using oxone (2KHSO5·KHSO4·K2SO4) as an oxidant under biphasic reaction conditions (CH2Cl 2/H2O) and tetra-n-butylammonium bromide as phase transfer agent under air at room temperature.
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Sisti,A.J.
, p. 2670 - 2673 (1970)
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STEREOCHEMICAL EFFECTS IN THE GAS-PHASE PINACOL REARRANGEMENT OF CIS- AND TRANS-1-METHYLCYCLOHEXANE-1,2-DIOL.
Cecchi, Patrizio,Cipollini, Romano,Pizzabiocca, Adriano,Renzi, Gabriele,Speranza, Maurizio
, p. 4847 - 4856 (1988)
The gas-phase pinacol rearrangement of cis and trans-1-methyl-1,2-cyclohexanediols, promoted by D3(+) and CnH5(+) (n= 1,2), was studied by the radiolytic method in the pressure range 100-760 Torr.Under all conditions, 2-methyl-cyclohexanone is the predominant product, arising from both substrates via different pinacol rearrangements and successive fast isomerisation of the corresponding primary intermediates, e,g, O-protonated 1-methyl-1-cyclopentanecarboxaldehyde.This conclusion is based from kinetic analysis of competition experiments with pinacol as reference substrate, carried out at high pressure (760 Torr) with or without added base (NMe3, 3 Torr), showing that the pinacol rearrngement rates are markedly dependent on the stereochemical features of the diol.Accordingly, the trans diol rearranges more rapidly than the cis isomer, which in turn isomerizes faster than pinacol, indicating that anti-periplanar CH2 migration to the vicinal tertiary C-OH2(+) center in trans (k2) is over five times faster than H migration in cis (k3).Analysis of the relative migrating ability of the different CH2 moieties in trans (k2 > k1) allowed exclusion of appreciable anchimeric assistance in these gas-phase pinacol rearrangements.The results are compared with revelant gas-phase data with those concerting the same substrates in acidic solution.
A new and highly effective method for catalytic oxidation of alcohols to the corresponding carbonyl compounds using the tris[(2-oxazolinyl)phenolato] manganese(III)/Oxone/n-Bu4NBr oxidation system
Bagherzadeh, Mojtaba
, p. 8943 - 8945 (2003)
Oxone (2KHSO5·KHSO4·K 2SO4) in the presence of mer-tris[(2-oxazolinyl)phenolato] manganese(III), Mn(phox)3, as catalyst under biphasic reaction conditions (CH2Cl2/H2O)
Reduction of nitrosoarene ligands in binuclear palladium(II) complexes
Orlova,Kazyul'kin,Shubochkin,Shishkin,Stromnova
, p. 1689 - 1692 (2001)
Reduction of the binuclear Pd11 complexes Pd2(OCOR)2(o-CH2C6H4-NO)2 (1) and Pd2(OCOR)2(o-PhN-C6H4-NO)2 (2) (where R = Me, C
Selective C-C Bond Cleavage of Cycloalkanones by NaNO2/HCl
He, Tianyu,Chen, Dengfeng,Qian, Shencheng,Zheng, Yu,Huang, Shenlin
supporting information, p. 6525 - 6529 (2021/09/02)
A novel selective fragmentation of cycloalkanones by NaNO2/HCl has been established. The C-C bond cleavage reaction proceeds smoothly under mild conditions, selectively affording versatile keto acids or oxime acids. The methodology can streamline the synthesis of valuable chiral molecules and isocoumarins from readily available feedstocks.
Synthesis of Chiral Amines via a Bi-Enzymatic Cascade Using an Ene-Reductase and Amine Dehydrogenase
Fossey-Jouenne, Aurélie,Jongkind, Ewald P. J.,Mayol, Ombeline,Paul, Caroline E.,Vergne-Vaxelaire, Carine,Zaparucha, Anne
, (2021/12/23)
Access to chiral amines with more than one stereocentre remains challenging, although an increasing number of methods are emerging. Here we developed a proof-of-concept bi-enzymatic cascade, consisting of an ene reductase and amine dehydrogenase (AmDH), to afford chiral diastereomerically enriched amines in one pot. The asymmetric reduction of unsaturated ketones and aldehydes by ene reductases from the Old Yellow Enzyme family (OYE) was adapted to reaction conditions for the reductive amination by amine dehydrogenases. By studying the substrate profiles of both reported biocatalysts, thirteen unsaturated carbonyl substrates were assayed against the best duo OYE/AmDH. Low (5 %) to high (97 %) conversion rates were obtained with enantiomeric and diastereomeric excess of up to 99 %. We expect our established bi-enzymatic cascade to allow access to chiral amines with both high enantiomeric and diastereomeric excess from varying alkene substrates depending on the combination of enzymes.