Sulfur-nitrogen Bond Research Articles

ChemInform Abstract: Copper‐Catalyzed Formation of Sulfur—Nitrogen Bonds by Dehydrocoupling of Thiols with Amines.

AbstractThe synthesis of sulfenamides and sulfonamides with aryl thiols and amines is catalyzed by a copper salt in air or under oxygen.

ChemInform Abstract: A Convenient Method for Production of Thionitrites and Disulfides under Mild and Heterogeneous Condition.

Abstract Thiols can be readily converted to their corresponding thionitrite with a combination of inorganic acidic salts and sodium nitrite in dichloromethane at room temperature. Disulfides result from the homolytic cleavage of the sulfur-nitrogen bond of the unstable thionitrite and subsequent coupling of the resultant thiyl radicals.

Copper‐Catalyzed Formation of Sulfur–Nitrogen Bonds by Dehydrocoupling of Thiols with Amines

AbstractCopper‐catalyzed formation of sulfur–nitrogen bonds can be performed by a dehydrocoupling of aryl thiols with amines. Sulfenamides or sulfonamides can be produced by the use of a copper catalyst in air or under oxygen atmosphere. Furthermore, a reaction involving the combination of a palladium catalyst and a copper catalyst selectively afforded sulfinamides.

Recent advances in transition metal-catalyzed N-atom transfer reactions of azides.

Transition metal-catalyzed N-atom transfer reactions of azides provide efficient ways to construct new carbon-nitrogen and sulfur-nitrogen bonds. These reactions are inherently green: no additive besides catalyst is needed to form the nitrenoid reactive intermediate, and the by-product of the reaction is environmentally benign N(2) gas. As such, azides can be useful precursors for transition metal-catalyzed N-atom transfer to sulfides, olefins and C-H bonds. These methods offer competitive selectivities and comparable substrate scope as alternative processes to generate metal nitrenoids.

Charge‐Transfer Complexes between the Sulfur Molecules SO2, S2O, S3, SONH, and SOCl2 and the Amine Donors NH3 and NMe3 – A Theoretical Study

AbstractThe formation of adducts between the acceptor molecules SO2, S2O, S3, and SOCl2 and the donor molecules ammonia and trimethylamine has been studied by high‐level G3X(MP2) theory, in most cases for the first time. Minimum energy structures with a 1:1 composition and with sulfur–nitrogen bonds have been located for all complexes. The thermodynamic properties, vibrational spectra, and atomic charges of these molecules have been calculated. Of the 10 investigated complexes, only SO2·NMe3 (2) and S2O·NMe3 (4) are predicted to be thermodynamically stable in the gas phase under standard conditions (ΔG°298 < 0). However, all adducts except S3·NH3 (5), SOCl2·NH3 (7), and SOCl2·NMe3 (8) are stable thermodynamically at 77 K. In a polar continuum with a dielectric constant (ϵ) of 40, complexes 2, 4, and S3·NMe3 (6) are stable even at 25 °C. However, if the adducts are formed in the polar continuum from the gaseous components, all adducts except S3·NH3 are formed not only exothermally but also exergonically. Complexes 2, 4, and 8 are the only species known in the solid state so far. The charge transfer from donor to acceptor in the various complexes in the gas phase ranges from 0.08 to 0.39 electrostatic units and correlates inversely with the S–N bond length, which ranges from 198 to 295 pm. In general, the charge transfer weakens the bonds within the acceptor molecule, which therefore may be considered to become activated. The formation of thionyl imide (SONH) from SOCl2 and NH3 is exergonic in the gas phase and the interaction between SONH and NH3 is very weak. In the case of SO2, the 1:2 complexes SO2·2NH3 (1a) and SO2·2NMe3 (2a), which contain two S–N bonds, are unstable with respect to their three‐component molecules both in the gas phase and in a polar medium at 25 °C, but they are stable in the polar phase with respect to the gaseous components.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Silica Phosphoric Acid/NaNO2 as a Novel Heterogeneous System for the Coupling of Thiols to Their Corresponding Disulfides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

SILICA PHOSPHORIC ACID/NaNO2 AS A NOVEL HETEROGENEOUS SYSTEM FOR THE COUPLING OF THIOLS TO THEIR CORRESPONDING DISULFIDES

Silica phosphoric acid was prepared via reaction of silica chloride (I) and phosphoric acid. Thiols can be readily converted to their corresponding thionitrites with a combination of silica phosphoric acid (II), wet SiO 2 , and sodium nitrite in dichloromethane at room temperature. Disulfides result from the homolytic cleavage of the sulfur–nitrogen bond of the unstable thionitrite and subsequent coupling of the resultant thiyl radicals.

SN versus S+N-: An Experimental and Theoretical Charge Density Study

To elucidate the bonding situation in the widely discussed hypervalent sulfur nitrogen species, the charge density distributions rho(r) and related properties of four representative compounds, methyl(diimido)sulfinic acid H(NtBu)(2)SMe (1), methylene-bis(triimido)sulfonic acid H(2)C[S(NtBu)(2) (NHtBu)](2) (2), sulfurdiimide S(NtBu)(2) (3), and sulfurtriimide S(NtBu)(3) (4), were determined experimentally by high-resolution low-temperature X-ray diffraction experiments (T = 100 K). This set of molecules represents an ideal frame of reference for the comparison of SN bonding modes, because they contain short formal S=N double bonds as well as long S-N single bonds, some of them influenced by inter- or intramolecular hydrogen bonds. For comparison, the gas-phase ab initio calculations of the four model compounds, H(NMe)(2)SMe, H(2)C[S(NMe)(2)(NHMe)](2), S(NMe)(2), and S(NMe)(3), were performed. The topological features were found to be not particularly sensitive with respect to different substituents R (R = H, Me, tBu). In this paper, it is documented that theory and experiment differ in the eigenvalues of the Hessian matrix because of systematically differing positions of the bond critical points but agree very well concerning the spatial Laplacian distribution and the distinct polarization of all investigated sulfur-nitrogen bonds. Both recommend the S(+)-N(-) formulation of sulfur nitrogen bonds in 1 and 2 since all nitrogen atoms are found to be sp(3) hybridized. The planar SNx (x = 2, 3) units in the diimide 3 and the triimide 4 reveal characteristics of m-center-n-electron systems. For none of the investigated S-N bonds, a classical double bond formulation can be supported. This is further substantiated by the NBO/NRT approach. Valence expansion to more than eight electrons at the sulfur atom can definitely be excluded to explain the bonding.

Free radical reactions of methionine in peptides: mechanisms relevant to beta-amyloid oxidation and Alzheimer's disease.

The pathogenesis of Alzheimer's disease is strongly associated with the formation and deposition of beta-amyloid peptide (beta AP) in the brain. This peptide contains a methionine (Met) residue in the C-terminal domain, which is important for its neurotoxicity and its propensity to reduce transition metals and to form reactive oxygen species. Theoretical studies have proposed the formation of beta AP Met radical cations as intermediates, but no experimental evidence with regard to formation and reactivity of these species in beta AP is available, largely due to the insolubility of the peptide. To define the potential reactions of Met radical cations in beta AP, we have performed time-resolved UV spectroscopic and conductivity studies with small model peptides, which show for the first time that (i) Met radical cations in peptides can be stabilized through bond formation with either the oxygen or the nitrogen atoms of adjacent peptide bonds; (ii) the formation of sulfur-oxygen bonds is kinetically preferred, but on longer time scales, sulfur-oxygen bonds convert into sulfur-nitrogen bonds in a pH-dependent manner; and (iii) ultimately, sulfur-nitrogen bonded radicals may transform intramolecularly into carbon-centered radicals located on the (alpha)C moiety of the peptide backbone.

Silica Chloride/NaNO 2 as a Novel Heterogeneous System for Production of Thionitrites and Disulfides Under Mild Conditions

Thiols can be readily converted to their corresponding thionitrites with a combination of silica chloride ( I ), wet SiO 2 and sodium nitrite in dichloromethane at room temperature. Disulfides result from the homolytic cleavage of the sulfur-nitrogen bond of the unstable thionitrite and subsequent coupling of the resultant thiyl radicals.

Silica sulfuric acid/NaNO 2 as a novel heterogeneous system for production of thionitrites and disulfides under mild conditions

Neat chlorosulfonic acid reacts with silica gel to give silica sulfuric acid in which sulfuric acid is immobilized on the surface of silica gel via covalent bond. Thiols can be readily converted to their corresponding thionitrites with a combination of silica sulfuric acid, wet SiO 2 and sodium nitrite in dichloromethane at room temperature. Disulfides result from the homolytic cleavage of the sulfur–nitrogen bond of the unstable thionitrites and subsequent coupling of the resultant thiyl radicals.

A Convenient Method for Production of Thionitrites and Disulfides Under Mild and Heterogeneous Condition

Thiols can be readily converted to their corresponding thionitrite with a combination of inorganic acidic salts and sodium nitrite in dichloromethane at room temperature. Disulfides result from the homolytic cleavage of the sulfur-nitrogen bond of the unstable thionitrite and subsequent coupling of the resultant thiyl radicals.

Muonium addition to sulfur-nitrogen chains

The first example of muonium addition to a sulfur-nitrogen double bond is reported. An ab initio calculation is used to assign the muon addition site as the nitrogen end of the double bond. The observed hyperfine coupling is 90.7 MHz. Copyright (C) 2000 John Wiley & Sons, Ltd.

Organic sulfur compounds as initiators of polymerization. VII. Polymerization of methyl methacrylate byN-[(p-benzoyl)benzenesulfonyl]benzenesulfonamide

The photopolymerization of methyl methacrylate in bulk using N-[(p-benzoyl)benzenesulfonyl]benzenesulfonamide as a photoinitiator was studied. A kinetic study of the photopolymerization showed that the rate of polymerization is proportional to the square root of the photoinitiator concentration. The decomposition of a sulfur–nitrogen bond and the obtained radicals are suggested to be responsible for the initiation of polymerization. The influence of the photoinitiator on the molecular weight was also studied. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:2083–2086, 1998

Organic sulfur compounds as initiators of polymerization. VII. Polymerization of methyl methacrylate by N‐[(p‐benzoyl)benzenesulfonyl]benzenesulfonamide

The photopolymerization of methyl methacrylate in bulk using N-[(p-benzoyl)benzenesulfonyl]benzenesulfonamide as a photoinitiator was studied. A kinetic study of the photopolymerization showed that the rate of polymerization is proportional to the square root of the photoinitiator concentration. The decomposition of a sulfur–nitrogen bond and the obtained radicals are suggested to be responsible for the initiation of polymerization. The influence of the photoinitiator on the molecular weight was also studied. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:2083–2086, 1998

The reactivity of aza-diferra-thia tetrahedranes Fe 2(CO) 6(μ-SNR): reductive cleavage of the SN bond and CO substitution

The reductive cleavage of the sulfur-nitrogen bond in the tetrahedrane Fe 2(CO) 6(μ-SNCH 3) ( 3) by means of [LiBEt 3H] was investigated. The dianionic intermediates thus formed were protonated to give a mixture of two isomers of Fe 2(CO) 6(μ-NHCH 3)(μ-SH) ( 6a/6b) which, in turn, were methylated to Fe 2(CO) 6(μ-NHCH 3)(μ-SCH 3) ( 8). Either one or two CO ligands in 3 could be substituted by tert-butyl isocyanide.

A linear relationship between the sulfur-nitrogen bond enthalpy term and bond length and an assessment of the reliability of empirical length-strength relationships in the estimation of thermochemical properties of sulfur-nitrogen compounds

Determination of themodynamic properties of S 4 N 4 H 4 , S 4 N 4 , S 4 N 2 , SN . , S 2 N + , SN + .

Kinetics and mechanism of the glutathione-dependent reduction of dehydromethionine

Dehydromethionine ( S-methylisothiazolidine-3-carboxylic acid) is reduced by glutathione (aqueous solution, 25°C) to give methionine and glutathione disulfide in a reaction that is dependent on pH and the nature and concentration of the buffer utilized. The data are consistent with proton-assisted, rate-limiting attack of glutathione thiolate anion on the sulfilimine sulfur with concomitant cleavage of the sulfur-nitrogen bond. The data predict a half-life for dehydromethionine ranging between 33 and 330 min in the presence of physiological concentrations of glutathione and phosphate buffer, suggesting that dehydromethionine and similar sulfilimines may have a sufficient lifetime in vivo to permit their use as carriers of oxidizing equivalents.

The reactions of organosulfur transfer reagents with Fe 2(CO) 9 and the synthesis of the Fe 2(CO) 6 derivative of α-lipoic acid

Treatment of Fe 2(CO) 9 with sulfur-transfer reagents of the types ImideSSImide and RSSImide where H-imide = phthalimide, succinimide, benzimidazole, morpholine and piperazine, and R  CH 2Ph and CMe 3 leads to cleavage of both the sulfursulfur bond and the sulfurnitrogen bond to give Fe 3(CO) 9S 2 in varying yields, some Fe 2(CO) 6S 2 plus low yields of the appropriate dimers of the type Fe 2(CO) 6(SR)(SR′), where R = R′ = phthal imido, CH 2Ph, CMe 3 and R = CH 2Ph, CMe 3, R′ = phthalimido. The naturally occurring cyclic disulfide D,L-α-lipoic acid, its methyl ester and amide react with Fe 2(CO) 9 to give Fe 2(CO) 6 derivatives wherein the sulfursufur bond has been broken.

ChemInform Abstract: INSERTION OF PLATINUM IN THE SULFUR‐NITROGEN BOND OF A 1,2,4‐THIADIAZOLE: SYNTHESIS OF A SIX‐MEMBERED METALLAHETEROCYCLE

Chemischer InformationsdienstVolume 16, Issue 19 Organoelement Compounds ChemInform Abstract: INSERTION OF PLATINUM IN THE SULFUR-NITROGEN BOND OF A 1,2,4-THIADIAZOLE: SYNTHESIS OF A SIX-MEMBERED METALLAHETEROCYCLE H. W. ROESKY, H. W. ROESKYSearch for more papers by this authorH. HOFMANN, H. HOFMANNSearch for more papers by this authorP. G. JONES, P. G. JONESSearch for more papers by this authorG. M. SHELDRICK, G. M. SHELDRICKSearch for more papers by this author H. W. ROESKY, H. W. ROESKYSearch for more papers by this authorH. HOFMANN, H. HOFMANNSearch for more papers by this authorP. G. JONES, P. G. JONESSearch for more papers by this authorG. M. SHELDRICK, G. M. SHELDRICKSearch for more papers by this author First published: May 14, 1985 https://doi.org/10.1002/chin.198519307Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume16, Issue19May 14, 1985 RelatedInformation