67512-92-9Relevant articles and documents
Stereoelectronic Effects: Perlin Effects in Thiane-Derived Compounds
Basche, Luis,Jung, Sebastian T.,Luy, Burkhard,Podlech, Joachim,Reinsperger, Tony
, (2020/04/15)
Stereoelectronic effects in thianes and thiane-derived sulfoxides, sulfones, sulfilimines, and sulfoximines were investigated by measuring 1JC,H coupling constants and by identification of normal and reversed Perlin effects, i.e., of differences in the coupling constants for equatorial and axial C–H bonds in the methylene groups of six-membered rings. The Perlin effects were correlated with results from natural bond orbital (NBO) analyses. NMR experiments were performed with conformationally restricted dimethyl- or tert-butyl-substituted derivatives, while the parent compounds were used for calculations. It turned out that the coupling constants are not only strongly influenced by stereoelectronic interactions with antiperiplanar C–H, C–C, C–O, and C–N bonds, but by the s character of the respective C–H bonds' carbon orbital as well.
The regiochemistry of cyclization of α-sulfenyl-, α-sulfinyl-, and α-sulfonyl-5-hexenyl radicals: Procedures leading to regioselective syntheses of cyclic sulfones and sulfoxides
Della, Ernest W.,Graney, Sean D.
, p. 3824 - 3835 (2007/10/03)
A study of the cyclization of α-sulfenyl-, α-sulfinyl-, and α-sulfonyl-5-hexenyl and 5-methyl-5-hexenyl radicals reveals a unique contrast in the mode of ring closure of the radicals. In the case of the 5-hexenyl radicals, the sulfinyl-substituted species displays unexpected regioselectivity relative to its analogues. Thus, while the α-S- and α-SO2-5-hexenyl radicals give measurable and increasing quantities of 6-endo product, the α-sulfinyl species cyclizes with high selectivity (95.5:4.5) via a 5-exo mode. By contrast, ring closure of the 5-methyl-5-hexenyl radicals is found to give substantially the 6-endo product in all cases. It is the α-sulfonyl-5-methyl-5-hexenyl radical that now exhibits high regioselectivity (97.5:2.5) for 6-endo closure: an illustration of the synthetic value of this observation is the independent synthesis of the model cyclohexyl sulfone 61 in high yield. It is found that ring closure under the conditions employed occurs irreversibly in all cases.
Regioselectivity of ring closure of 2-thia- and 2-sulfonyl-5-methyl-5-hexenyl radicals
Della, Ernest W.,Graney, Sean D.
, p. 4065 - 4067 (2007/10/03)
(matrix presented) Ring closure of the α-substituted radicals 4 (X = S, SO2) is observed to be irreversible and to lead to significant amounts of the product of 6-endo cyclization. Indeed, reduction of the sulfonyl-based radical 4 (X = SO2
Surface-mediated reactions. 8. Oxidation of sulfides and sulfoxides with tert-butyl hydroperoxide and OXONE
Kropp, Paul J.,Breton, Gary W.,Fields, John D.,Tung, Jesse C.,Loomis, Brian R.
, p. 4280 - 4285 (2007/10/03)
Silica gel and alumina have been found to mediate the oxidation of sulfides and sulfoxides with (CH3)3COOH and OXONE. With all combinations except (CH3)3COOH/alumina, sulfides were oxidized with reasonably good selectivity to sulfoxides. These studies afforded insights into the mechanisms of surface-mediated processes. Adsorption studies, combined with the effect of partial silylation of silica gel, indicate that oxidation of sulfides by (CH3)3COOH/silica gel occurs at least predominantly via nucleophilic attack by the sulfide on (CH3)3COOH, which is activated by being bound to isolated silanol sites on the silica gel surface (Scheme 2), whereas oxidation of sulfoxides involves nucleophilic attack by (CH3)3COOH on the sulfoxide, which is activated by being bound to associated silanol sites (Scheme 3). Oxidation of sulfoxides by (CH3)3COOH/alumina involves attack of (CH3)3COO- on the sulfoxide bound to free Al+ sites on the surface (Scheme 4B). Mediation of oxidation by OXONE involves instead activation by its being dispersed on the surface of the adsorbent, providing contact between KOSO2OOH, the oxidizing component, and the substrate. With silica gel, binding involves the associated silanol sites (Scheme 5). It is proposed that this is a general model for surface mediation of inorganic salts.
