15848-08-5Relevant academic research and scientific papers
Kinetics and Mechanism of the Methyltrioxorhenium-Catalyzed Sulfoxidation of Thioketones and Sulfines
Huang, Ruili,Espenson, James H.
, p. 6374 - 6376 (2007/10/03)
Kinetic studies have been carried out on the oxidation of thiobenzophenones and thiocamphor by hydrogen peroxide and on the second step in the sequence, oxidation of the resulting sulfines (Ar2C= S=O). The first reaction follows the pattern now common to methyltrioxorhenium/H2O2 reactions, in that the rate constant for the reaction between the peroxorhenium intermediate and the thioketone follows a Hammett correlation such that electron-releasing substrates react more rapidly. The reaction constant is p = -1.12. However, the plot of log(kX/kH) for the sulfines against 2σ, determined over the range -1.6 2 under these conditions rather than undergoing disproportionation to SO2 and S. Also, SO was trapped with a 1,3-diene as a thiophene-1-oxide.
Reaction of Thioketones with Carbonyl Oxides and 3,3-Dimethyl-1,2-dioxirane. Cycloaddition vs. Oxygen Atom Transfer
Tabuchi, Toshihiko,Nojima, Masatomo,Kusabayashi, Shigekazu
, p. 3043 - 3046 (2007/10/02)
The ozonolysis of vinyl ethers 1a, b in the presence of adamantane-2-thione 4a and bicyclononan-9-thione 4b gave in each case the corresponding thioozonides 5a-c in moderate yields, whilst ozonolysis of a mixture of vinyl ethers 1a-d and thiobenzophenone derivatives 4f-h gave the corresponding thione S-oxides 8f-h in isolated yields of 10-40percent, together with the benzophenones 7f-h. 3,3-Dimethyl-1,2-dioxirane, generated in situ from the reaction of acetone and 'oxone' (2KHSO5-KHSO4-K2SO4), transferred an oxygen atom to compounds 4a, f, g, i providing the thione S-oxides 8a, f, g, i in 29-97 percent yield.
Reaction of Carbonyl Oxides and Thioketones. Cycloaddition vs. Oxygen Atom Transfer
Tabuchi, Toshihiko,Nojima, Masatomo,Kusabayashi, Shigekazu
, p. 625 - 627 (2007/10/02)
The ozonolysis of vinyl ethers (1a, b) in the presence of thioadamantan-2-one (4a) gave in each case the corresponding thio-ozonide (5a, b) in around 70percent yield, whilst ozonolysis of a mixture of vinyl ethers (1a-c) and thiobenzophenone derivatives (4b-d) gave the corresponding thione-S-oxides (8b-d) in 15-30percent yields, together with the benzophenones (6b-d).
Elimination Reactions of Alkanesulfinyl Derivatives: Mechanism and Reactivity in Base-Induced Sulfine Formation from Methyl Diarylmethanesulfinates
Kice, John L.,Rudzinski, Juliusz J.
, p. 2414 - 2421 (2007/10/02)
Upon treatment in methanol at room temperature with methoxide ion methyl diarylmethanesulfinates, ArAr'CHS(O)OCH3 (1), and methyl 9-fluorenesulfinate (2) undergo elimination readily to afford the corresponding sulfines (3 and 4) in quantitative yield.Studies in CD3O-/CD3OD show that, surprisingly, elimination of 1 to give 3 is significantly faster than nucleophilic substitution by methoxide ion at the sulfinyl group (exchange of CH3O by CD3O).Even more unexpected, the kinetic isotope effect for elimination of 2-9-d (kH/kD=6.1) and absence of detectable H/D exchange of the methine proton of 1 in CD3OD prior to sulfine formation extablish that, even though the leaving group is MeO-, the elimination takes place by either an irreversible ElcB or an E2 mechanism, rather than the reversible ElcB mechanism found (ref 4 and 7) for the analogous sulfene-forming elimination of arylmethanesulfonate esters with oxyanion leaving groups of comparable pKa.Reaction of amines with 2 in methanol also gives sulfine 4, and the amine-induced elimination, which has a large Broensted β, also proceeds by either an (ElcB)irrev or an ElcB-like E2 mechanism.Why sulfine-forming eliminations of 1 and 2 favor an (ElcB)irrev or E2 mechanism whereas sulfene-forming eliminations of arylmethanesulfonates with even better leaving groups proceed by an (ElcB)rev mechanism is considered and a possible explanation presented.
