82135-89-5Relevant academic research and scientific papers
Stereoselective synthesis of medium-sized cyclic compounds by means of tandem reactions of a cyclic oxosulfonium ylide with acetates of Baylis-Hillman adducts
Akiyama, Hitoshi,Fujimoto, Tetsuya,Ohshima, Katsuyoshi,Hoshino, Kenji,Saito, Yuko,Okamoto, Ayu,Yamamoto, Iwao,Kakehi, Akikazu,Iriye, Ryozo
, p. 2265 - 2272 (2007/10/03)
Treatment of a five-membered cyclic oxosulfonium ylide 3 with β-acetoxy-α-methylene ketones in the presence of two equimolar amounts of base afforded the cycloheptene oxide derivatives 7a-i as single stereoisomers in 19-77% yields. The products were considered to form through a Michael-type addition of the ylide, followed by elimination of the acetoxy group and an intramolecular Corey-Chaykovsky reaction. On the other hand, the same treatment, when using a six-membered oxosulfonium ylide, gave the corresponding cyclooctene oxide derivatives in moderate yields, with the products formed in a ca. 4:1 mixture of stereoisomers, a fact correlated with differences in the configuration of the sulfur atom in the sulfinyl group.
One-Electron Chemical Reductions of Phenylalkylsulfonium Salts
Beak, Peter,Sullivan, Thomas A.
, p. 4450 - 4457 (2007/10/02)
Twenty-two arylalkylsulfonium salts have been reduced with potassium in graphite in tetrahydrofuran and the sulfide products identified.Two trialkylsulfonium salts did not reduce under these conditions.Comparison of the sulfides from a series of monophenylalkylsulfonium salts reveals a leaving-group propensity of benzyl > secondary > primary > methyl > phenyl in a ratio of 28:(6.0 +/- 0.3):1.0:(0.53 +/- 0.09): 0.05.The cleavage ratio is shown to be independent of the electron source and the homogeneity of heterogeneity of the reaction in two cases.Multiplicative transitivity of the above ratios is not observed, although the same qualitative order is found for other comparisons.These results are interpreted in terms of the initial formation of a ?-ligand radical anion sulfonium cation, which undergoes cleavage to a carbon radical and a sulfide.This appears to be the first evidence for this type of structure in a sulfur system.Leaving-group propensities different from the above order are observed in reductions of diphenylsulfonium and benzo-fused sulfonium salts, and rationales are offered.The intermediates in these reactions appear to be different from those involved in radical additions to, or displacements on, sulfur.
