920-56-9Relevant academic research and scientific papers
Hydrolysis rates of alkyl and aryl sulfinamides: evidence of general acid catalysis
Piggott, Andrew M.,Karuso, Peter
, p. 7452 - 7455 (2008/03/13)
Sulfinamides are important in enantioselective synthesis, as rare post-translational modifications of proteins and as isosteres of the amide bond. Little is known about the rates of hydrolysis for aliphatic sulfinamides or the mechanism of hydrolysis. In this Letter, we show that sulfinamides hydrolyse by predominantly a non-specific acid/base catalysis with phosphate buffer but by varying the buffer concentration, it was possible to determine the hydrolysis rates of a range of sulfinamides with water through non-linear least squares regression.
Hydrolysis Rates of Saturated Acyclic and Cyclic Sulfinamides: X-ray Crystal Structures of an Acyclic Sulfinamide and γ-Ammoniopropanesulfinate
Wagner, Barbara J.,Doi, Joyce Takahashi,Musker, W. Kenneth
, p. 5940 - 5945 (2007/10/02)
The rates of the neutral hydrolysis of a saturated acyclic sulfinamide, N,N-dimethylmethanesulfinamide (CH3S(O)N(CH3)2), the monocyclic compounds (isothiazolidine 1-oxide, 2-(1-phenylethyl)isothiazolidine 1-oxide, tetrahydrothiazine 1-oxide) and the bicyclic compounds (9-thia-1-azabicyclononane 9-oxide and 2-thia-1-azabicyclononane 2-oxide) were determined in D2O using 1H NMR at 65 deg C.The first-order rate constants are similar to those of β-lactams.Activation parameters were determined for the acyclic, one cyclic, and one bicyclic sulfinamide.The striking feature which arises is that the parameters for the hydrolysis of the acyclic sulfinamide (ΔH(excit.) = 11 +/- 4 kcal mol-1; ΔS(excit.) = -47 +/- 11 cal mol-1 K-1) are much different from both the monocyclic sulfinamide and the bicyclic sulfinamide (ΔH (excit.) ca. 23 +/- 2 kcal/mol-1; ΔS(excit.) ca. -15 +/- 4 cal mol-1 K-1, respectively).As a consequence, the acyclic sulfinamide hydrolyzes about 25 times faster than the cyclic sulfinamides.Most other heterocyclic compounds hydrolyze more rapidly than their acyclic analogues.Thus, the factors influencing the relative rates of hydrolysis of sulfinamides appear to be acting in a unique manner.The X-ray crystal structure of the first simple sulfinamide, N-(1-phenylethyl)methanesulfinamide, and a zwitterionic ammoniosulfinate, 3-((1-phenylethyl)ammonio)propanesulfinate, are also reported.
Multinuclear NMR Study of Variously Substituted Sulphonamides and Sulphinamides
Ruosteuso, P.,Haekkinen, A.-M.,Mattila, T.
, p. 189 - 193 (2007/10/02)
13C, 15N and 17O NMR chemical shifts, and also 1J(CH) and 1J(NH) values, have been determined for variously substituted sulphonamides and some sulphinamides, either neat or in acetone or dimethyl sulphoxide solution.The effect of benzene ring substitutens on the chemical shifts of nitrogen and oxygen nuclei is slight, but N-substitution changes the shielding of both nuclei.Generally, an N-methyl substituent shields an amide nitrogen and an N,Ndimethyl substituent gives further slight shielding.On the other hand, an N-phenyl substituent deshilds the nitrogen strongly, but the deshielding effect of an N,N-diphenyl substituent is markedly smaller.The sulphonyl oxygens are deshilded relative to the sulphinyl oxygens, and N-methyl and N,N-dimethyl substituents shild the oxygen nucleus.The effect of N-phenyl and N,N-diphenyl substituents on the shielding of the oxygen atoms of the sulphonyl group is slight.The direct 1J(CH) coupling constants are similar, but they are characteristic of different type of sulphur amides.The 1J(NH) values are of the same order of magnitude for sulphonamides and sulphinamides, but are clearly smaller for N-unsubstituted amides than for N-substituted compounds.KEY WORDS Sulphonamide Sulphinamide Multinuclear NMR
Carbon-13, Nitrogen-15, Oxygen-17 and Sulphur-33 NMR Chemical Shifts of Some Sulphur Amides and Related Compounds
Haakkinen, A.-M.,Ruostesuo, P.
, p. 424 - 427 (2007/10/02)
15N, 17O and 33S NMR chemical shifts were determined for some aliphatic and aromatic sulphonamides, sulphinamides, sulphenamides and related sulphones and sulphoxides.The 17O and 33S NMR chemical shifts change only slightly for the sulphonyl compounds.In the sulphinyl compounds, on the other hand, the presence of nitrogen causes a noticeable shift to higher frequencies in the 17O resonance.The differences between the 17O chemical shifts of sulphinyl and sulphonyl compounds are more noticeable than those between sulphinamides and sulphoxides.The 15N NMR chemical shifts of sulphon-, sulphin- and sulphenamides reflectbwell the effect of the environments of both nitrogen and the adjacent sulphur atom.The correlations between 15N, 17O and 33S NMR chemical shifts and the structures of sulphur amides and related sulphones and sulphoxides are discussed.The chemical shifts of the 13C nuclei are also presented.
