“…The error limits in Table assume only random errors. It is unclear why 1a decomposed in previous studies 9,18 though the cleavage of dialkoxy disulfides is both acid- 2,5 and base-sensitive. ,− 1 Eyring plot of the rotation about the S−S bond in 1a in DMSO- d 6 .…”
Section: Resultsmentioning
confidence: 93%
“…It is unclear why 1a decomposed in previous studies 9,18 though the cleavage of dialkoxy disulfides is both acid-2,5 and basesensitive. 2,[65][66][67] Clearly the electronic effect shown in Table 3 did not affect the barrier to rotation (see ∆G q 298 , Table 4). Thus, the high barrier in dialkoxy disulfides is a function not of the electronics of the R group but intrinsically that of the OS-SO moiety.…”
A substrate study was undertaken in order to probe the scope of S(2)Cl(2) coupling of alcohols to form dialkoxy disulfides. Compounds 1b and 1f are new; along with 1a, 1c, 1h, and 1j, all of the title compounds are fully characterized, and the yields of 1a and 1c have been optimized from previously reported syntheses. The effect of the R-substituent about the OSSO moiety has been carefully probed as yields vary. A substrate and a solvent study of the coalescence behavior of this class was carried out. The origin of the inherently large barrier to rotation and the resultant thermal decomposition pathway is discussed. Both phenomena are shown to be solvent independent; hindered rotation is substrate independent. The decomposition of 1a is ca. 7 kcal/mol higher than the barrier to rotation about the S-S bond. The combined evidence suggests acyclic unsymmetric homolytic cleavage of the dialkoxy disulfide.
“…The error limits in Table assume only random errors. It is unclear why 1a decomposed in previous studies 9,18 though the cleavage of dialkoxy disulfides is both acid- 2,5 and base-sensitive. ,− 1 Eyring plot of the rotation about the S−S bond in 1a in DMSO- d 6 .…”
Section: Resultsmentioning
confidence: 93%
“…It is unclear why 1a decomposed in previous studies 9,18 though the cleavage of dialkoxy disulfides is both acid-2,5 and basesensitive. 2,[65][66][67] Clearly the electronic effect shown in Table 3 did not affect the barrier to rotation (see ∆G q 298 , Table 4). Thus, the high barrier in dialkoxy disulfides is a function not of the electronics of the R group but intrinsically that of the OS-SO moiety.…”
A substrate study was undertaken in order to probe the scope of S(2)Cl(2) coupling of alcohols to form dialkoxy disulfides. Compounds 1b and 1f are new; along with 1a, 1c, 1h, and 1j, all of the title compounds are fully characterized, and the yields of 1a and 1c have been optimized from previously reported syntheses. The effect of the R-substituent about the OSSO moiety has been carefully probed as yields vary. A substrate and a solvent study of the coalescence behavior of this class was carried out. The origin of the inherently large barrier to rotation and the resultant thermal decomposition pathway is discussed. Both phenomena are shown to be solvent independent; hindered rotation is substrate independent. The decomposition of 1a is ca. 7 kcal/mol higher than the barrier to rotation about the S-S bond. The combined evidence suggests acyclic unsymmetric homolytic cleavage of the dialkoxy disulfide.
“…Diethyl sulfite can be prepared from ethylene, water, and sulfur dioxide with silver sulfate as catalyst (181). Meuwsen (158,159,160) obtained this compound by oxidating diethyl sulfoxylate.…”
“…Their preparation, first described by Meuwsen and Gebhardt,1 and subsequently utilized by others,3 involved the alkoxidecatalyzed decomposition of the corresponding dialkoxy disulfides. As the latter were readily avail-able3® the preparation of additional dialkyl sulfoxylates EtONa EtOSSOEt -> EtOSOEt + 8° (1) was undertaken. Despite the success achieved by Meuwsen and Gebhardt with diethyl sulfoxylate,1 their method was found to give low yields, and in our hands, it was not generally useful.…”
Section: Villamentioning
confidence: 99%
“…The possibility that two or more sulfur atoms may be linked in a branched fashion, >S=S, as opposed to the usual linear -S-Slinkage has been a matter of debate for many years. The facile conversion of polysulfides to disulfides by alkalis or cyanides has often been adduced to indicate that the removable sulfur (1) Preliminary communication! Q. E. Thompson, .…”
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