ABSTRACT
A new flavin catalyst 2 immobilized in an ionic liquid ([BMIm]PF6) was used for the highly selective oxidation of sulfides to sulfoxides by hydrogen peroxide. The sulfoxides were obtained in good to high yields and high selectivity without any detectable overoxidation to sulfone. The catalyst in the ionic liquid was recycled up to seven times without loss of activity or selectivity.
Subject(s)
Flavins/chemistry , Ionic Liquids/chemistry , Catalysis , Hydrogen Peroxide , Molecular Structure , Oxidation-Reduction , Sulfides/chemistryABSTRACT
La ascitis quilosa (AQ) es una entidad rara asociada a la patología del sistema linfático. El primer caso pediátrico fue reportado por Morton en 1683 en un paciente con tuberculosis. Puede producirse por una malformación linfática congénita, una obstrucción o trauma
Subject(s)
Humans , Child , Child Abuse/diagnosis , Octreotide/administration & dosage , SomatostatinABSTRACT
La ascitis quilosa (AQ) es una entidad rara asociada a la patología del sistema linfático. El primer caso pediátrico fue reportado por Morton en 1683 en un paciente con tuberculosis. Puede producirse por una malformación linfática congénita, una obstrucción o trauma
Subject(s)
Humans , Child , Child Abuse/diagnosis , Octreotide/administration & dosage , Somatostatin/administration & dosageABSTRACT
Eight different flavin derivatives have been synthesized and the electronic effects of substituents in various positions on the flavin redox chemistry were investigated. The redox potentials of the flavins, determined by cyclic voltammetry, correlated with their efficiency as catalysts in the H2O2 oxidation of methyl p-tolyl sulfide. Introduction of electron-withdrawing groups increased the stability of the reduced catalyst precursor.
Subject(s)
Flavins/chemistry , Alkylation , Catalysis , Electrochemistry , Kinetics , Models, Molecular , Molecular Conformation , Oxidation-Reduction , Sulfides/chemistryABSTRACT
A highly chemoselective oxidation of allylic and vinylic sulfides to the corresponding sulfoxides has been developed using flavin 1 as the oxidation catalyst and hydrogen peroxide as the terminal oxidant. The sulfoxides were formed in good to excellent yields in a highly selective manner even when an excess of the oxidant was used. Sulfone formation was completely suppressed to <0.5% (in one single case 1.5% sulfone was detected). No epoxidation of double bonds or interference with other functional groups was observed under the reaction conditions. The general applicability was demonstrated by the selective oxidation of various allylic and vinylic sulfides having different electronic properties. A number of functionalities including hydroxy, acetoxy, amino, silyloxy, and formyl groups are tolerated under these mild reaction conditions.
