Thioethers compounds

Related to the crown ethers are compounds, such as hexamethyl-[14]-4,ll-diene (6), which differ by the replacement of one or more of the oxygen atoms by other kinds of donor atoms, particularly N or S. MacrocycHc amine and thioether compounds have been synthesized. Compounds having more than one kind of heteroatom in the ring are called mixed-donor macrocycles. The naturally occurring metaboUtes nonactin [6833-84-7] and monactin [7182-54-9] have both ether and ester groups incorporated in the macrocyclic stmcture. 

In many cases the M—S bond has been found to be normal in length, i.e. the bond distances agree fairly well with the sum of the covalent radii (Pauling s scale, data appropriate to coordination number and oxidation state). However, in some complexes the M—S distances are significantly shorter than the calculated ones, for example in thioether compounds with Cr°, Pd11, Pt, Cu1 and Au1. This observation has often led to the suggestion that the shortening is due to some Jt-back-donation from the metal to the sulfur. 

Contrary to the mass spectra of mercaptans or disulfides, however, the mass spectra of various thioether compounds (e.g. 8, JL 2 and 1 5) show no loss of an acetyl... 

Fumes B, Schlenk D. Extrahepatic metabolism of carbamate and organophosphate thioether compounds by the flavin-containing monooxygenase and cytochrome P450 systems. Drug Metab Dispos 2005 33 214—218. 

Transplatin reacts 360 times faster than cisplatin with glutathione [27], a reaction likely to remove platinum from the cell, through ATP-dependent efflux [28]. It has been shown that a thioether ligand on a platinum triamine complex can be slowly replaced by a guanine-N(7), suggesting a possible platinum transporter role for such thioether compounds towards DNA [6], (This topic is discussed in the contribution by J. Reedijk and J. M. Teuben.)... 

Reaction with mercaptans and dimercaptans (12, 16, 21) proceeds normally to produce the 2-hydroxybenzyl thioether compounds XXV and XXVI. 

The reactions of the OH radicals with two model thioether compounds, S-ethylthioacetate (SETAc) (H3C-CH2-S-C(=0)-CH3) and S-ethylthioacetone (SETA) (H3C-CH2-S-CH2-C(=0)-CH3, containing electron withdrawing acetyl groups in the a and f3 positions, with respect to the sulfur atom have been studied by pulse radiolysis. The a-positioned acetyl group in SETAc destabilizes >S -OH radicals within the five-membered structure that leads to the formation of alkyl-substituted radicals H2C -CH2-S-C(=0)-CH3 and H3C-CH2-S-C(-0)- CH2. At high proton and SETAc concentration, the OH-induced oxidation does not lead to intermolecularly three-electron-bonded dimeric radical cations SETAc(S.. S), only the a-(alkylthio)alkyl radicals H3C- CH-S-C(=0)-CH3 were observed (Amax = 420 nm). These observations are rationalized in terms of the... 

In the thioether compound 129, Sn—S coordination was established on the basis of a temperature-dependent lineshape analysis of the H NMR resonances of the diastereotopic SEt group (156). 

Methyl thioethers from benzyl thioethers Compounds containing isotopes... 

Selected Bond Distances and Angles in Mercuric-Thioether Compounds... 

Thioethers have also been shown to form strong complexes with Hg(II) in aqueous solution (47, 104, 105, 127, 137). The chelate effect has been utilized in several of these thioether compounds in efforts to improve chelation therapy in Hg(II) poisoning (13). Several of the formation constants of ligand systems based on thioethers are in Table IX. In contrast to thiolates, only weak Hg(II)-thioether complexes are formed in highly donating solvents such as dimethyl sulfoxide and pyridine (213). 

Desorption Time. One-half to one hour with good agitation is usually sufficient desorption time for most systems. Once optimum desorption has taken place, the system is generally stable however, some exceptions have been observed Some compounds react or are readsorbed after an optimum desorption time as shown in Fig. 5. The active surface of the sorbent may act as a catalyst. Methanol has been shown to react with carbon disulfide in the presence of charcoal to form polysulfides, mercaptans and polyether-thioether compounds Decanting the solvent from the sorbent usually corrects this problem. 

X = O or S) <85JOM(295)33,86SA(A)I255,87JOM(320)273>. The spectra for the ether and thioether compounds were very similar, although it was not possible to conclude whether the heteroatom in each case was coordinated to the antimony. 

NUCLEOSIDASES AND RELATED ENZYMES - HYDROLYSING THIOETHER COMPOUNDS... 

Various commercially available thiols react photochemically with tetravinylsUane to give the corresponding tetrasubstituted thioether compounds ... 

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