Studies on the Oxidation of some Sulfides with Pyridinium Dichromate in Acetonitrile medium

Kinetic evidence of a common mechanism in the oxidations of diethyl sulfide by dichromates and halochromates of heterocyclic bases

“…Panigrahi and Mahapatro 26 postulated the PCC oxidation of organic sulfides as a two‐electron transfer process. Hence the chromium(VI) oxidation of diethyl sulfide may involve a two‐electron process with the formation of chromium(IV) in the rate‐determining step (Scheme ) 19–21, 26. Experiments reveal involvement of chromium(IV) intermediate in the oxidation of diethyl sulfide by the chromium(VI) reagents; manganese(II) ion suppresses the oxidation rates but marginally.…”

“…However, investigations on the comparison of the rates and mechanisms of oxidations of a substrate by these chromium(VI) reagents are rare. Since the chromium(VI) oxidation of organic sulfides has been extensively examined 17–21 diethyl sulfide is the substrate for the present study. Most of the kinetic investigations on the oxidation by chromium(VI) complexes were made in aqueous acetic acid and hence the selection of the solvent for this work.…”

Impact of added ligand oxides in the sulfoxidation of phenylmercaptoacetic acids with oxovanadium(IV)‐salen complexes

“…Similar nonlinear concave downward Hammett plots were reported during the oxidation of anils by isonicotinium dichromate, [ 96 ] conversion of rhenium azides to imido complexes, [ 97 ] nucleophilic substitution reactions between N ‐methyl‐ α ‐bromoacetanilides and benzylamines, [ 98 ] reaction of β ‐benzoylamines with pseudomonas fluorescens kynureninase, [ 99 ] pyridinolysis of methyl phenyl phosphinic chloride, [ 100 ] oxidation of sulfides with pyridinium dichromate, [ 101 ] and vanadium catalyzed sulfoxidation. [ 102 ]…”

“…Similar nonlinear concave downward Hammett plots were reported during the oxidation of anils by isonicotinium dichromate, [96] conversion of rhenium azides to imido complexes, [97] nucleophilic substitution reactions between N-methyl-α-bromoacetanilides and benzylamines, [98] reaction of β-benzoylamines with pseudomonas fluorescens kynureninase, [99] pyridinolysis of methyl phenyl phosphinic chloride, [100] oxidation of sulfides with pyridinium dichromate, [101] and vanadium catalyzed sulfoxidation. [102] In contradiction, nonlinear concave upward Hammett plots were observed in the oxidative decarboxylation of PSAA [13] and sulfoxidation of PMAA [14] by [oxo(salen) chromium(V) + ] complexes in the presence of ligand oxides; oxidative decarboxylation of PSAA by iron (III) polypyridyl complexes [38] ; oxidation of substituted transcinnamic acids by pyridinium chlorochromate, [103] chloramines, [104] and acid bromate [105] ; oxygen atom transfer reaction of axially ligated Mn(V)oxo complexes [106] ; and stereoselective catalytic sulfoxidations mediated by titanium and zirconium trialkylanolamine complexes.…”