Sulfinyl Oxygen Research Articles

Consecutive O-S/N-S Bond Cleavage in Gold-Catalyzed Rearrangement Reactions of Alkynyl N-Sulfinylimines.

Gold-catalyzed reactions of alkynyl N-sulfinylimines were used to produce the corresponding 2H-azirines possessing sulfenyl and acyl groups at the 3-position of the azirine ring in good to excellent yields. These reactions involved internal transfer of the sulfinyl oxygen atom to form a thiooxime intermediate tethered to an α-oxo gold carbene moiety. Subsequent insertion of the carbene into the N-S bond resulted in ring construction.

Consecutive O−S/N−S Bond Cleavage in Gold‐Catalyzed Rearrangement Reactions of Alkynyl N‐Sulfinylimines

AbstractGold‐catalyzed reactions of alkynyl N‐sulfinylimines were used to produce the corresponding 2H‐azirines possessing sulfenyl and acyl groups at the 3‐position of the azirine ring in good to excellent yields. These reactions involved internal transfer of the sulfinyl oxygen atom to form a thiooxime intermediate tethered to an α‐oxo gold carbene moiety. Subsequent insertion of the carbene into the N−S bond resulted in ring construction.

Electrocrystallization, structural and physicochemical characterization of a novel copper(II) dinuclear paddle-wheel complex with sulindac, [Cu2(Suln)4]∙3H2O

The electrocrystallization, structural and magnetic characterization of a copper(II) complex with the anti-inflammatory drug sulindac [HSuln = 2-[(3Z)-6-fluoro-2-methyl-3-[(4-methylsulfanylphenyl)methylidene]inden-1-yl]acetic acid], with formula [Cu2(C20H16FO3S)4]∙3H2O, is reported. Single crystals were grown directly on the surface of a sacrificial copper wire and were suitable for X-ray diffraction analysis. The complex is a 1D polymeric coordination complex consisting of paddlewheel moieties, formed by four sulindacate units bridging two copper(II) ions, and three disordered water molecules occupying the voids in the unit cell, with axially connected units through the neighboring sulfinyl oxygen atom located in the phenyl moiety. The complex presents a strong antiferromagnetic exchange interaction. Variable temperature magnetic susceptibility displays an unusual increase in the magnetic moment with decreasing temperature from 60 to 30 K, which may be indicative of the presence of a small amount of a monomeric Cu(II) species or traces of molecular oxygen. The product was additionally characterized by FTIR, UV–Vis spectroscopy, and TGA/DTA-DSC.

ChemInform Abstract: Regioselective Synthesis of 1,2‐ and 1,3‐Diaminothiacalix[4]arenes via Nucleophilic Aromatic Substitution and Their X‐Ray Structures.

Thiacalix[4]arenes bearing two amino groups instead of two hydroxy groups of p-tert-butylthiacalix[4]arene (2) at the distal 1,3- (5b) and proximal 1,2-positions (5c) are regioselectively synthesized via the nucleophilic aromatic substitution (SNAr) reaction of lithium benzylamide with tetra-O-methylsulfinylcalix[4]arenes 4(rctt) and 4(rcct), respectively. The SNAr reaction selectively proceeds at the benzene rings between two neighboring sulfinyl groups of a trans conformation. This is rationalized by the cooperative coordination of a methoxy group with a neighboring sulfinyl oxygen atom toward the metal ion to form a six-membered chelate, through which the amide ion attacks the aromatic nucleus. The N,O-hybrid thiacalixarenes 5b and 5c adopt cone conformations in their acetonitrile inclusion crystals. The distances between adjacent N and/or O atoms of their narrow-rim substituents indicate that the four substituents form a circular hydrogen-bond network but it is weaker than that of original thiacalixarene 2. Compound 5c also adopts a cone conformation in the guest-free crystal. This, combined with the fact that tetraaminated p-tert-butylthiacalix[4]arene 5a adopts a 1,3-alternate conformation in its guest-free crystal, indicates that the intramolecular O⋯N hydrogen bonds, not to mention the O⋯O hydrogen bond, in compound 5c play a crucial role in maintaining a cone conformation in the crystal.

Regioselective synthesis of 1,2- and 1,3-diaminothiacalix[4]arenes via nucleophilic aromatic substitution and their X-ray structures

Thiacalix[4]arenes bearing two amino groups instead of two hydroxy groups of p-tert-butylthiacalix[4]arene (2) at the distal 1,3- (5b) and proximal 1,2-positions (5c) are regioselectively synthesized via the nucleophilic aromatic substitution (SNAr) reaction of lithium benzylamide with tetra-O-methylsulfinylcalix[4]arenes 4(rctt) and 4(rcct), respectively. The SNAr reaction selectively proceeds at the benzene rings between two neighboring sulfinyl groups of a trans conformation. This is rationalized by the cooperative coordination of a methoxy group with a neighboring sulfinyl oxygen atom toward the metal ion to form a six-membered chelate, through which the amide ion attacks the aromatic nucleus. The N,O-hybrid thiacalixarenes 5b and 5c adopt cone conformations in their acetonitrile inclusion crystals. The distances between adjacent N and/or O atoms of their narrow-rim substituents indicate that the four substituents form a circular hydrogen-bond network but it is weaker than that of original thiacalixarene 2. Compound 5c also adopts a cone conformation in the guest-free crystal. This, combined with the fact that tetraaminated p-tert-butylthiacalix[4]arene 5a adopts a 1,3-alternate conformation in its guest-free crystal, indicates that the intramolecular O⋯N hydrogen bonds, not to mention the O⋯O hydrogen bond, in compound 5c play a crucial role in maintaining a cone conformation in the crystal.

Competition of Charge- versus Radical-Directed Fragmentation of Gas-Phase Protonated Cysteine Sulfinyl Radicals

The fragmentation behavior of various cysteine sulfinyl ions (intact, N-acetylated, and O-methylated), new members of the gas-phase amino acid radical ion family, was investigated by low-energy collision-induced dissociation (CID). The dominant fragmentation channel for the protonated cysteine sulfinyl radicals ((SO•)Cys) was the radical-directed Cα-Cβ homolytic cleavage, resulting in the formation of glycyl radical ions and loss of CH2SO. This channel, however, was not observed for protonated N-acetylated cysteine sulfinyl radicals (Ac-(SO•)Cys); instead, charge-directed H2O loss followed immediately by SH loss prevailed. Counterintuitively, the H2O loss did not derive from the carboxyl group but involved the sulfinyl oxygen, a proton, and a Cβ hydrogen atom. Theoretical calculations suggested that N-acetylation significantly increases the barrier (~14 kcal mol(-1)) for the radical-directed fragmentation channel because of its reduced capability to stabilize the thus-formed glycyl radical ions via the captodative effect. N-Acetylation also assists in moving the proton to the sulfinyl site, which reduces the barrier for H2O loss. Our studies demonstrate that for cysteine sulfinyl radical ions, the stability of the product ions (glycyl radical ions) and the location of the charge (proton) can significantly modulate the competition between radical- and charge-directed fragmentation.

Relative stabilities of transition states determine diastereocontrol in sulfur ylide additions onto chiral N‐sulfinyl imines

Additions of methylphenylsulfonium methylide onto chiral non-racemic N-sulfinyl imines (R'-SO-N=CH-R, R'=t-butyl, R=protected diol), followed by ring closure, yield terminal aziridines with high diastereoselectivity. Control reactions have established that both N- and C- iminyl substituents impact product preference, and when properly matched, one addition product is selected almost exclusively. Using solution-phase density functional computational methods, minima and transition state searches have been performed to reveal the structural origins of the diastereoselectivity. Our computational findings indicate that ring closure is fast and irreversible, and consequently, the relative energies of the transition states for the competing Re/Si addition steps determine the product diastereomeric ratios. Analysis of addition transition state structures reveals the causes of selectivity as arising from the N- and C- iminyl substituents, and we identify the S (R) configuration of the N-sulfinyl sulfur atom as the dominant director of Si (Re) addition. The control attributed to the sulfur configuration is tied to an important favorable internal interaction between the sulfinyl oxygen and the iminyl hydrogen. The protected diol acts as a secondary director, owing to steric/electrostatic interactions with the approaching ylide.

Synthesis of Enantiomerically Pure Allenes with Central and Axial Chirality Mediated by a Remote Sulfinyl Group

Enantiomerically pure 2-(p-tolylsulfinyl)benzylcopper reagents react with propargyl bromides and mesylates, affording enantiomerically pure allenes with central and axial chirality. Both regioselectivity (SN2′ processes) and configuration at the chiral axis are completely controlled by the sulfinyl group. The stereoselectivity at the benzylic position is very high. Complete kinetic resolution and moderate dynamic resolution of racemic propargylic mesylates can be achieved. This stereochemical behavior can be explained by assuming the stabilization of the benzylcopper by the sulfinyl oxygen and the association of the triple bond to the metal as a previous step of the intramolecular SN2′ nucleophilic attack.

Hydrogen‐Bond Control in Axially Chiral Styrenes: Selective Synthesis of Enantiomerically Pure C2‐Symmetric Paracyclophanes

The ansa to a synthetic problem: A hydrogen bond between a phenol and a sulfinyl oxygen atom can lend axial chirality to styrene derivatives. A C2-symmetric precursor containing two such sulfinyl styrene motifs with a shared diphenol ring enables the stereoselective formation of an ansa chain (see scheme). This approach provides access to various enantiomerically pure [10]- and [12]paracyclophanes with a benzene or naphthalene platform.

Tetra- and Di-Nuclear Copper(II) Complexes with Stereoisomers of Sulfinylcalix[4]arene Arising from the Disposition of Four S=O Groups

Abstract A systematic investigation was conducted on the structures of tetra- and di-nuclear copper(II) complexes with three stereoisomers of sulfinylcalix[4]arenes (H4L), the isomerism of which is determined by the disposition of the sulfinyl oxygen with respect to a reference oxygen from the mean plane containing four sulfur atoms. The sulfinylcalix[4]arene with a trans–cis–trans S=O orientation (H4Lrtct) reacted with Cu(OAc)2 to form [CuII4(Lrtct)(OAc)3(μ-MeO)(MeOH)] (1), in which Lrtct4− adopts a cone conformation to afford tetrakis fac-tridentate coordination through four phenoxo oxygens and four sulfinyl groups giving a square CuII4 core. Ligands H4Lrccc and H4Lrctt having cis–cis–cis and cis–trans–trans configurations formed [CuII4(Lrccc)(OAc)3(μ-OH)] (2) and [CuII4(Lrctt)(OAc)3(μ-OH)] (3), respectively, which have common features, such as a cone-type conformation of L4−, tetrakis fac-tridentate coordination fashion, and tetracopper(II) core in a square-pyramidal geometry. The similarities among 1–3 clearly show that sulfinylcalix[4]arenes can coordinate to CuII in a fac-tridentate fashion via a donor atom X (O or S) from a sulfinyl group and two flanking phenoxo O−s and that X is simply determined by the X–Cu distance. Using [Cu(acac)2] as a copper(II) source, H4Lrctt formed [CuII2(H2Lrctt)2] (4), suggesting the significance of auxiliary ligand for bridging copper(II) centers to assemble the core, that is, the acetato ligands in complexes 1–3 are needed to form the core structure. Metal–metal interactions were investigated by means of magnetic susceptibility, and it was found that both ferro- and antiferromagnetic interactions occur in tetracopper(II) complex 3. In contrast, antiferromagnetic interaction is present in dicopper(II) complex 4.

Computational study of 4‐fluoro‐4‐chloro‐ and 4‐fluoro‐4‐bromo‐4‐silathiacyclohexane S‐oxides: Effect of halogen on the SO→Si intramolecular coordination in the boat and twist conformers

AbstractChair, twist, and boat conformations of axial and equatorial 4‐fluoro‐4‐chloro‐ and 4‐fluoro‐4‐bromo‐4‐silathiacyclohexane S‐oxides have been calculated at the second‐order Møller–Plesset (MP2) and density functional theory (DFT) levels of theory. The 2,5‐twist and 1,4‐boat conformers of the axial sulfoxides are stabilized by transannular interaction between the sulfinyl oxygen and silicon to give trigonal bipyramidal geometry at silicon. The stability of conformers containing pentacoordinate silicon is governed by the balance of the transannular sulfinyl oxygen–silicon coordination, nonbonded H…H and O…Hlgax interactions, electronegativity of Hlgax and nucleofugality of Hlgeq, and may approach the stability of the lowest‐energy chair conformers. The effect of pentacoordination on the energy and geometry of Si‐halogenated 4‐silathiane S‐oxides is analyzed as a function of the halogen nature and position. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007

Ab initio DFT calculations of the configurational and conformational preferences of 2-phenylsulfinylcyclohexanones — Evidence for "exo-anomeric" interactions

The conformational analysis of 2-phenylsulfinylcyclohexanone by ab initio density functional calculations is described. Six conformations corresponding to axial/equatorial isomers and rotation about the exocyclic C2—S bond in each of the RR or RS diastereomers were calculated and the results were examined in terms of relative energies, electrostatic interactions, orbital interactions, and geometrical variations. The global minimum conformation was the RS isomer that positioned the phenylsulfinyl moiety in an equatorial orientation and the sulfinyl oxygen in an anti orientation with respect to the carbonyl carbon atom. Of the other three low energy conformations, only one had a gauche arrangement of these atoms, and only in one of the four lower energy conformations was evidence found for a S-O(–)···C(+)-O electrostatic interaction. In contrast, the results were consistent with the operation of nS → [Formula: see text] stabilizing orbital interactions. Further support for this hypothesis was obtained from the increased C=O bond lengths in these four conformations relative to the other conformations, and by the torsional angle distortion away from ideal geometry, presumably to maximize the stabilizing orbital interaction. We propose that this conformational preference is a manifestation of a generalized exo-anomeric effect. The longer C2—S bond in the axial isomers was also interpreted in terms of a stabilizing πC=O → [Formula: see text] interaction, analogous to an endo-anomeric interaction. Comparison of the computational results to available experimental data on the conformational equilibrium of each diastereomer in solution suggests which conformers are present in each of the equilibria. The available data for the solid state indicate that the RR and RS isomers both crystallize in high energy conformations, stabilized by intermolecular interactions.Key words: 2-phenylsulfinylcyclohexanones, configurational isomers, conformational preferences, DFT calculations, exo-anomeric effect.

Computational study of conformations and of sulfinyl oxygen-induced pentacoordination at silicon in 4-chloro-4-silathiacyclohexane 1-oxide and 4,4-dichloro-4-silathiacyclohexane 1-oxide

Second-order Møller–Plesset theory (MP2) and density functional theory (B3LYP) with the 6-311G(d,p) and 6-311+G(d,p) basis sets have been used to calculate the equilibrium geometries and relative energies of the chair, twist, and boat conformations of 4-chloro-4-silathiacyclohexane 1-oxide and 4,4-dichloro-4-silathiacyclohexane 1-oxide. The chair conformers of the axial sulfoxides are lower in energy than the chair conformers of the corresponding equatorial sulfoxides. MP2/6-311+G(d,p) predicted the chair conformer of axial trans-4-chloro-4-silathiacyclohexane 1-oxide ( 4a) to be 6.12, 0.44, and 0.45 kcal/mol, respectively, more stable than the corresponding 1,4-twist ( 4b), 2,5-twist ( 4c) and 1,4-boat ( 4d) conformers and 6.93 kcal/mol more stable than the 2,5-boat transition state ([ 4e] ‡). Structures 4c and 4d are stabilized by intramolecular coordination of the sulfinyl oxygen with silicon that results in trigonal bipyramidal geometry at silicon. The 1,4-boat conformer ( 7d) of axial 4,4-dichloro-4-silathiacyclohexane 1-oxide is also stabilized by transannular coordination of the sulfinyl oxygen with silicon. The energy difference ( E rel = 4.23 kcal/mol) between the chair conformer ( 7a) and 7d is larger than that between 4a and 4d. The relatively lower stability of the 1,4-boat conformer ( 7d) of axial 4,4-dichloro-4-silathiacyclohexane 1-oxide ( 7a) may be due to repulsive interactions of the axial halogen and sulfinyl oxygen atoms. The relative energies and structures of the conformers and transition states of cis- and trans-4-chloro-4-silathiacyclohexane 1-oxide and 4,4-dichloro-4-silathiacyclohexane 1-oxide are discussed in terms of hyperconjugative interactions, orbital interactions, nonbonded interactions, and intramolecular sulfinyl oxygen–silicon coordination.

Highly Stereoselective Vinylogous Pummerer Reaction Mediated by Me3SiX.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Relative energies of conformations and sulfinyl oxygen‐induced pentacoordination at silicon in 4‐bromo‐ and 4,4‐dibromo‐4‐silathiacyclohexane 1‐oxide: A computational study

AbstractThe equilibrium geometries and relative energies of the chair, twist, and boat conformations of cis‐ and trans‐4‐bromo‐4‐silathiacyclohexane 1‐oxide and 4,4‐dibromo‐4‐silathiacyclohexane 1‐oxide have been calculated at the B3LYP/6‐311G(d,p) and MP2/6‐311+G(d,p) theoretical levels. The axial (SO) chair conformers of the sulfoxides are of lower energy than the chair conformers of the corresponding equatorial (SO) sulfoxides. The chair conformer of the axial (SO) trans‐4‐bromo‐4‐silathiacyclohexane 1‐oxide is only 0.10 kcal/mol more stable than the corresponding 1,4‐boat conformer which is stabilized by a transannular coordination of the sulfinyl oxygen with silicon that results in trigonal bipyramidal geometry at silicon. The 1,4‐boat structure of equatorial (SO) trans‐4‐bromo‐4‐silathiacyclohexane 1‐oxide is a transition state and is 5.77 kcal/mol higher in energy than the respective chair conformer. The 1,4‐boat conformer of axial (SO) 4,4‐dibromo‐4‐silathiacyclohexane 1‐oxide is also stabilized by transannular coordination of the sulfinyl oxygen and silicon, but it is 4.31 kcal/mol higher in energy than the corresponding chair conformer. The relatively lower stability of the 1,4‐boat conformer of 4,4‐dibromo‐4‐silathiacyclohexane 1‐oxide may be due to repulsive interactions of the axial halogen and sulfinyl oxygen atom. The relative energies of the conformers and transition states are discussed in terms of hyperconjugative interactions, orbital interactions, nonbonded interactions, and transannular sulfinyl oxygen‐silicon coordination. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005

Highly Stereoselective Vinylogous Pummerer Reaction Mediated by Me3SiX

A highly stereoselective vinylogous Pummerer rearrangement involving 1,4-migration of the sulfinyl oxygen atom occurs when ortho-sulfinyl benzyl carbanions are treated with trimethylsilyl halides. The reaction proceeds in good yield and affords optically pure benzyl alcohols with extremely high enantioselectivity (ee > 98%).

Computational study of sulfoxides of thiacyclohexane, 4‐silathiacyclohexane, 4‐fluoro‐4‐silathiacyclohexane, and 4,4‐difluoro‐4‐silathiacyclohexane: Relative energies of conformations and sulfinyl oxygen stabilized pentacoordinate silicon in boat and twist structures

AbstractSecond‐order Møller‐Plesset theory (MP2) has been used to calculate the equilibrium geometries and relative energies of the chair, 1,4‐twist, 2,5‐twist, 1,4‐boat, and 2,5‐boat conformations of thiacyclohexane 1‐oxide (tetrahydro‐2H‐thiopyran 1‐oxide), 4‐silathiacyclohexane 1‐oxide, cis‐ and trans‐4‐fluoro‐4‐silathiacyclohexane 1‐oxide, and 4,4‐difluoro‐4‐silathiacyclohexane 1‐oxide. At the MP2/6‐311+G(d,p) level of theory, the chair conformer of axial thiacyclohexane 1‐oxide is 0.99, 5.61, 5.91, 8.57, and 7.43 kcal/mol more stable (ΔE) than its respective equatorial chair, 1,4‐twist, and 2,5‐twist conformers and 1,4‐boat and 2,5‐boat transition states. The chair conformer of equatorial thiacyclohexane 1‐oxide is 4.62, 6.31, 7.56, and 7.26 kcal/mol more stable (ΔE) than its respective 1,4‐twist and 2,5‐twist conformers and 1,4‐boat and 2,5‐boat transition states. The chair conformer of axial 4‐silathiacyclohexane 1‐oxide is 1.79, 4.26, 3.85, and 5.71 kcal/mol more stable (ΔE) than its respective equatorial chair, 1,4‐twist, and 2,5‐twist conformers and 2,5‐boat transition state. The 2,5‐twist conformer of axial 4‐silathiacyclohexane 1‐oxide is stabilized by a transannular interaction between the sulfinyl oxygen and silicon, to give trigonal bipyramidal geometry at silicon. The chair conformer of equatorial 4‐silathiacyclohexane 1‐oxide is 2.47, 7.90, and 8.09 kcal/mol more stable (ΔE) than its respective 1,4‐twist, and 2,5‐twist conformers and 2,5‐boat transition state. The chair conformer of axial cis‐4‐fluoro‐4‐silathiacyclohexane 1‐oxide is 4.18 and 5.70 kcal/mol more stable than its 1,4‐twist conformer and 2,5‐boat transition state and 1.51 kcal/mol more stable than the chair conformer of equatorial cis‐4‐fluoro‐4‐silathiacyclohexane 1‐oxide. The chair conformer of axial trans‐4‐fluoro‐4‐silathiacyclohexane 1‐oxide is 5.02 and 6.11 kcal/mol more stable than its respective 1,4‐twist conformer and 2,5‐boat transition state, but is less stable than its 2,5‐twist conformer (ΔE = −1.77 kcal/mol) and 1,4‐boat transition state (ΔE = −1.65 kcal/mol). The 2,5‐twist conformer and 1,4‐boat conformer of axial trans‐4‐fluoro‐4‐silathiacyclohexane 1‐oxide are stabilized by intramolecular coordination of the sulfinyl oxygen with silicon that results in trigonal bipyramidal geometry at silicon. The chair conformer of axial 4,4‐difluoro‐4‐silathiacyclohexane 1‐oxide is 3.02, 5.16, 0.90, and 6.21 kcal/mol more stable (ΔE) than its respective equatorial chair, 1,4‐twist, and 1,4‐boat conformers and 2,5‐boat transition state. The 1,4‐boat conformer of axial 4,4‐difluoro‐4‐silathiacyclohexane 1‐oxide is stabilized by a transannular coordination of the sulfinyl oxygen with silicon that results in a trigonal bipyramidal geometry at silicon. The relative energies of the conformers and transition states are discussed in terms of hyperconjugation, orbital interactions, nonbonded interactions, and intramolecular sulfinyl oxygen–silicon coordination. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005

Conformational analysis and electronic interactions of 2‐thiosubstituted cyclohexanones by semiempirical method PM3

AbstractSome 2‐phenylthio‐para–substituted cyclohexanones with different oxidation states of sulfur atom were studied by systematic conformational search around C–S bonds using the parametric method 3 (PM3) Hamiltonian. The axial and equatorial regular chair conformations were subjected to calculations and each one produced three rotamers: +gauche (+G), −gauche (−G), and anti (A). The axial conformations were more populated than the equatorial ones. The para‐substituent and sulfur group effects over conformational populations and carbonyl polarizations suggest that the main electronic interaction between sulfur atom and carbonyl group are of repulsive nature in both axial (such as S+C+O) and equatorial (such as S−CO−) conformations. The axial +G conformation is the more stable for all compounds, except for (R2,SS)‐sulfinyl isomer, because it allows an attractive electrostatic interaction between C–O and S–ϕ bond dipoles (such as S+CO−). The axial A conformation is the more stable for (R2,SS)‐sulfinyl compounds, because the sulfinyl oxygen is at −G position near the carbonyl group and an attractive electrostatic interaction (such as OC+O) can take place. The higher carbonyl polarization and negative charge of carbon C–2 plus hydrogen H–2 of cyclohexanone ring for sulfonyl compared with sulfanyl and sulfinyl compounds, can be explained by a through‐space interaction instead through‐bond inductive effects. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 95: 313–321, 2003

α-Phosphoryl sulfoxides. Part XII. The question of sulfinyl oxygen participation in the alkaline hydrolysis of α-phosphoryl sulfoxides

The course of the alkaline hydrolysis of (diphenoxyphosphoryl)methyl p-tolyl sulfoxide (8) has been elucidated by a combination of 18O isotopic labelling and mass spectrometric analysis of the hydrolysis products. The hydrolysis of the sulfoxide 8 containing 18O in the sulfinyl group afforded the corresponding phosphonic acid 9, which, upon methylation with diazomethane, was converted into [methoxy(phenoxy)phosphoryl]methyl p-tolyl sulfoxide (10) also containing 18O in the sulfinyl group, as demonstrated by the EI- and CI-mass spectra. The hydrolysis of 8 in 18O-enriched water followed by methylation with diazomethane gave the sulfoxide 10 in which 18O was incorporated into the phosphonic ester moiety. These results do not support a two-step mechanism for the hydrolysis of α-phosphoryl sulfoxides involving participation of the neighbouring sulfinyl group and formation of a cyclic oxathiaphosphetane intermediate. The latter is most probably formed in the mass spectrometric fragmentation process of α-phosphoryl sulfoxides.

Polysulfonylamine, CV. Die ersten N,N-disulfonylierten Sulfinsäureamide: Synthese und Kristallstrukturen von RS(O)-N(SO2Me)2 (R = Me, CCl3) / Polysulfonylamines, C V. The First N,N -Disulfonylated Sulfinic Amides: Synthesis and Crystal Stru ctures of RS(O)-N(SO2Me)2 (R = Me, CCl3)

Abstract The novel sulfinamides RS(O) -N(SO2Me)2, where R = Me (1a) or CCl3 (1b), were obtained by treating the corresponding sulfinyl chlorides with Me3SiN(SO2Me)2 or AgN-(SO2Me)2, respectively. A presumedly ionic 1:1 adduct of 1b with 4-dimethylaminopyridine was isolated and analytically characterized. In the crystals of 1a (monoclinic, space group P21/c) and 1b (monoclinic, P21/c) , the molecules feature approximately planar NS3 moieties, unusually long S(O) -N bonds and, in the case of 1b, an extremely long S(O) -C bond [for la and 1b, in order: sum of bond angles at nitrogen 359.5 and 357.1°, S(O) -N 178.2(2) and 173.6(2) pm, S(O) -C 178.8(2) and 194.1(2) pm]. In both molecular structures, an attractive S(O) ··· O 1,4-interaction leads to a 7.3° discrepancy in the S(O) -N -SO2 angles. The crystal packing of 1a displays a tape (double-chain) motif generated by two prominent intermolecular C -H ··· O interactions involving one MeSO2 group and the sulfinyl oxygen atoms of two adjacent molecules, whereas in 1b the molecules are associated into parallel chains via a bonding Cl ⋯ O(sulfonyl) interaction.