Sulfur-containing carboxylic acids. 5. Synthesis and structure of dialkyl sulfides and dialkyl sulfoxides with vicinal carboxyl or acylamino groups
摘要:
Bifunctional sulfides and sulfoxides containing carboxy, carbamoyl, or acylamino groups in the beta-position are synthesized, and their IR spectra were studied. An unusual decrease in the.frequencies of the carbonyl vibrations (by 20-34 cm-1) was found for thiodipropionic acid, its amides, and bis(beta-acylaminoethyl) sulfides by comparison with the corresponding sulfoxides. The low-frequency shift of the CO band in these carbonylsulfides was not, as expected, associated with the intramolecular S...O coordination, since the x-ray structural investigation of thiodipropionic acid and bis(2-trifluoroacetylaminoethyl) sulfide did not show short intra- and intermolecular contacts involving the sulfur atom. Both structures contain intermolecular hydrogen bonds (C-O...HO or C=O...HN).
Herein, we describe a mild and efficient two-step procedure to introduce a thiol group on aromatic substrates. First, reaction with an activated sulfoxide leads to an arylsulfonium salt intermediate. Then, two successive beta-elimination-based dealkylation reactions afford the desired arylthiols in good to excellent yields.
We disclose a direct C(sp)–, C(sp2)–, and C(sp3)–H thiolation reaction using β-sulfinylesters as the versatile sulfur source. The key step of this protocol is chemoselective C–S bond cleavage of the sulfoniumsalts that are formed in situ from the corresponding alkenes, alkynes, and 1,3-dicarboxyl compounds with β-sulfinylesters. The successful capture of the acrylate byproduct supports a retro-Michael
De Jonge, Cornelis R. H. I.; Hageman, Hendrik J.; Huysmans, Willem G. B., Journal of the Chemical Society. Perkin transactions II, 1973, # 9, p. 1276 - 1279
作者:De Jonge, Cornelis R. H. I.、Hageman, Hendrik J.、Huysmans, Willem G. B.、Mijs, Willem J.
DOI:——
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An Efficient and Straightforward Access to Sulfur Substituted [2.2]Paracyclophanes: Application to Stereoselective Sulfenate Salt Alkylation
A straightforward and high-yielding access to various [2.2]paracyclophanes possessing a sulfur-based functional group is reported, the key step being a SEAr reaction mediated by a sulfonium salt. The versatility of the methodology was exemplified by an original application in sulfenate salt chemistry, from which a remarkable chirality transfer was observed.