70428-56-7Relevant articles and documents
Selective conversion of epoxides to vic-halo alcohols and symmetrical or unsymmetrical dihalides by triphenylphosphine/2,3-dichloro-5,6-dicyano-1,4- benzoquinone (DDQ) in the presence of quaternary ammonium halides
Iranpoor, Nasser,Firouzabadi, Habib,Aghapour, Ghasem,Nahid, Azarmidokht
, p. 1885 - 1891 (2004)
A new method is described for the efficient and selective conversion of epoxides to vic-halo alcohols or symmetrical and unsymmetrical dihalides using PPh3/DDQ/R4NX (X = Cl, Br, I) as a mixed-reagent system.
Semisynthetic enzymes in asymmetric synthesis: Enantioselective reduction of racemic hydroperoxides catalyzed by seleno-subtilisin
Haering, Dietmar,Schueler, Ellen,Adam, Waldemar,Saha-Moeller, Chantu R.,Schreier, Peter
, p. 832 - 835 (2007/10/03)
The serine protease subtilisin was chemically converted into the peroxidase-active seleno-subtilisin. This semisynthetic enzyme catalyzes the enantioselective reduction of racemic hydroperoxides in the presence of thiophenols to yield optically active hydroperoxides and alcohols on the semipreparative scale. The kinetic parameters and enantioselectivities of seleno-subtilisin-catalyzed reduction of various chiral hydroperoxides were determined. The catalytic efficiency of this semisynthetic enzyme is comparable to that of the native horseradish peroxidase. The sense in the enantioselectivity of the seleno-subtilisin is opposite to the natural enzymes previously used in the synthesis of optically active hydroperoxides. Consequently, the semisynthetic enzyme selenosubtilisin complements the naturally available peroxidases for the asymmetric synthesis of both enantiomers.
Preassociation, free-ion, and ion-pair pathways in the electrophilic bromination of substituted cis- and trans-stilbenes in protic solvents
Ruasse, Marie-Fran?oise,Lo Moro, Giacomo,Galland, Bernard,Bianchini, Roberto,Chiappe, Cinzia,Bellucci, Giuseppe
, p. 12492 - 12502 (2007/10/03)
Rates and products of electrophilic bromination of ring-substituted cis- and trans-stilbenes have been investigated in acetic acid, trifluoroethanol, ethanol, methanol, and water-methanol mixtures. The mY(Br) relationships (linear for nucleophilic solvent
Kinetics and Mechanism of Oxidation of Formic Acid and Oxalic Acid by N-Bromoacetamide in Perchloric Acid Medium
Bishnoi, M. L.,Negi, S. C.,Banerji, K. K.
, p. 699 - 700 (2007/10/02)
The title reactions are first order each in N-bromoacetamide (NBA) and the substrates.The rate decreases linearly with an increase in and this is attributed to the formation of kinetically inactive hypobromous acidium ion, (H2OBr(+)).The reaction is retarded by added acetamide.Hypobromous acid has been postulated as the active oxidising species.Kinetic isotope effect is not present.In the mechanism proposed the rate-determining step involves formation of formyl or oxalyl hypobromite which then decomposes in a fast step to give the products, mostly CO2.