Sulfene

Abstract: Four sulfines have so far been prepared by elimination of HCl from sulfinyl chlorides with triethylamine and by oxidation of diaryl thioketones with peracid. They are colored, crystalline compounds, which slowly decompose at room temperature. Attempts to prepare sulfenes have not yet been successful, but mesylsulfene[1] has been isolated as the trimethylamine adduct. It can be shown by interception reactions that sulfenes are formed as intermediates by the action of trialkylamines on aliphatic sulfonyl chlorides and by the action of sulfur dioxide on diazoalkanes. They react with ROD to form monodeuterated sulfonates, with diazoalkanes to give three-membered rings, with enamines, dienamines, ketene O,O,O,N-, and N,N-acetals, and chloral, and in some cases with vinyl ethers, to give four-membered rings. They also react with nitrones to give five-membered rings, and with β-aminovinyl ketones and dienamines to give six-membered rings.

Abstract: Thiete 1,1-dioxide (1) rearranges to 5H-1,2-oxathiole-2-oxide (3) on heating in solution or in the vapor phase. The presence of phenol in the solution leads to formation of phenyl 2-propene-1-sulfonate (CH2=CHCH2SO2OPh) in 15% yield. The results are rationalized in terms of a mechanism involving vinylsulfene (2). Flash thermolysis of some thietane 1,1-dioxides (16) and 3-thietanone 1,1-dioxides (15) gave products derived from extrusion processes, but 3-thietanol 1,1-dioxide (17) yielded, among other products, acetaldehyde and formaldehyde. The latter is believed to arise by "desulfinylation" of sulfene (CH2=SO2) formed along with the enol form of acetaldehyde by cycloreversion from 17.

Abstract: The first catalytic asymmetric synthesis of β-sultones is reported. This development has enabled a rapid access to a number of highly enantioenriched biologically interesting sulfonyl and sulfinyl compound classes, which makes use of the inherent ring strain of the four-membered heterocycles. The products possess either two vicinal stereocenters, such as in β-hydroxy-sulfonamides, -sulfonates, -sulfones, -sulfonic acids, -sulfinic acids, γ-sultines, and γ-sultones or a single stereocenter, such as in α-branched alkyl or allyl sulfonic acids. This work also represents the first application of sulfene intermediates in asymmetric catalysis. The reactivity of a sulfene normally acting as an electrophile could be reverted by the formation of a nucleophilic zwitterionic sulfene-amine adduct. To achieve a combination of high enantioselectivity and reactivity, cooperative catalytic action of a chiral nucleophilic tertiary amine (the cinchona alkaloid derivative diydroquinine 2,5-diphenyl-4,6-pyrimidinediyl diether ((DHQ)(2)PYR)) and Bi(OTf)(3) or In(OTf)(3) was of primary importance.

Abstract: pH-rate profiles, primary kinetic isotope effects, deuterium substitution patterns, and pH-product ratios in the presence of added nucleophiles provide evidence for the following overlapping set of mechanisms for the hydrolysis of methanesulfonyl chloride (1) (in 0.1 M KCl at 25 o C): (a) pH≤1-6.7, reaction with water by direct nucleophilic attack on the sulfonyl chloride; (b) pH≥6.7-11.8, rate-determining attack by hydroxide anion to form sulfene (2), which is then trapped by water in a fast step; and (c) pH≥11.8, sulfene formation and sulfene trapping by hydroxide anion