Structure and mechanism of hydrolysis of diaryl(acylamino)(chloro)-λ4-sulfanes and diaryl(acylamino)sulfonium salts

摘要: Aryl (methylaminocarbonylaryl) sulfides were converted by t-BuOCl to diaryl(acylamino)(chloro)-λ4-sulfanes or the corresponding diaryl(acylamino)sulfonium chlorides depending on substituent of S-aryl group. 1H NMR data showed that chloro-λ4-sulfanes exist only in CDCl3 and DMSO-d6 solvents, whereas CD3OD complete ionic dissociation takes place, leading sulfonium chlorides. Both chemical shifts signals NOE suggest salts having an o-MeO, o-Cl o-Me phenyl ring assume a skew conformation, aryl compounds without ortho-substituent can rotate practically free about S–C(1′) axis. In o-MeO-substituted derivatives there exists equatorial 1,4 type S ⋯ O close contact. Sulfonium with axial 1,5 contacts involving neighbouring COOMe, CONHMe, COMe NO2 groups occur butterfly like spiro-λ4-sulfanes. There is correlation between 15N shift amide-nitrogen elongation S–N covalent bond, which interdepending S–N, S–Cl bonds be characterized. Effective intermolecular interaction was detected centre solvent molecules negatively polarized oxygen atom. The hydrolysis yielding sulfoxides investigated kinetic method 98∶2 (v/v) dioxane–water mixture water. On basis medium, (ρ +1.03), steric, salt isotope effects detailed mechanisms hydroxy-λ4-sulfane intermediate are proposed. more reactive five-membered hetero hydrolyzed water, less analogues six-membered attacked OH− ions.