Sodium thiophenoxide alkyl

The a-chloroalkyl phenyl sulfides are prepared by reaction of the corresponding alkyl bromide with sodium thiophenoxide to give an alkyl phenyl sulfide, which is then chlorinated by NCS. 

An alternative synthesis of a-methyiene ketones and esters is provided by enolate alkylation using benzyl bromomethyl sulfide followed by oxidative elimination (Scheme 10). The addition of sodium thiophenoxide to a-methylenebutyrolactones has been recommended for protection of the sensitive double bond, which can be regenerated by oxidative elimination. ... 

The three different second-order processes thus exhibit widely different kinetic behaviour towards the varying base concentration at constant buffer ratio. In theory this dependence should provide a means of assigning the mechanism. An advantage over the isotopic exchange approach is that it should be possible to detect carbanion intermediates that eliminate more rapidly than they protonate. Unfortunately, the kinetics are not always clear-cut. The E2 mechanism can, under certain conditions, follow specific base catalysis, especially if one base is of much greater catalytic efficiency than the other bases present (e.g. the E2 reaction of l,l,l-trichloro-2,2-di-p-chlorophenyl-ethane with sodium thiophenoxide in methanol) . Alternatively, the base may be sufficiently powerful to produce a kinetically significant concentration of lyate ions (e.g. the E2 reaction of alkyl bromides with phenoxides in ethanol) " . 

The replacement of an a hydrogen of an alkyl halide by halogen decreases Sn2 reactivity. Chloroform, however, is about one thousandfold more reactive in basic hydrolysis than methylene chloride . Every bromine-containing halo-form studied (Table 7) is at least 600 times as reactive toward hydroxide ions in 66.7% aqueous dioxan as methylene bromide ". Toward weakly basic nucleophiles, such as thiophenoxide ion, the predicted reactivity order is obeyed haloforms have been found to be less reactive than the corresponding methylene halides . The reaction of haloforms with sodium thiophenoxide is strongly accelerated, however, by the presence of hydroxide ions - . These observations are quite unexplainable in terms of scheme (22). 

Sodium thiophenoxide, 138, 296 Spiroannulation, 51, 76, 276, 511 Spiro(4.5] decanes, 118-119 Spiroenones, 239 Spiro ethers, 172 Spiro-/S-methglene-7-lactones, 187 Squaric acid. 144, 145 Steganacin, 114, 122, 123 Steviobioside, 44 Stevioside, 44 Stigmasterol, 158, 371 Stobbe condensation, 296 Stork alkylation, 283 Styrene, 119, 309... 

Nitrophenyl l-thio-P-o-mannopyranoside has been synthesized by reaction of acetochloromannose [207] or the mannosyl bromide 2 [202] with the sodium salt of 4-nitrothiophenol. A similar reaction between sodium thiophenoxide and aceto-bromomannose in HMPT gives phenyl 1-thio-P-D-mannopyranoside quantitatively [208]. In a related reaction the sodium salt of 1-thio-P-D-mannopyranose has been alkylated with benzyl bromide as in Schmidt s approach (Section 13.2.4) to give benzyl P-thiomannoside in 86% yield [209]. P-Linked 1-thiomannopyranosides can also be prepared by BFs-catalyzed anomerization of the readily available a-anomers [46]. The Lindberg protocol has also been used for the synthesis 1-thio-P-D-mannopyranosides [146, 149]. Aryl 1-thio-p-mannofuranosides have been syn-... 

In 2010, Ueda and Hartwig reported on an iridium-catalyzed asymmetric allylation of sodium sulfinates 345 to branched allylic sulfones 348 with high regioselectivities and enantioselectivities (Scheme 46.40). Notably, the reaction proceeded with a broad range of acyclic allylic carbonates 346 and aryl and alkyl sodium sulfinates 345. Most recently, Zhao et al. developed the catalytic asymmetric allylic alkylations of acyclic allylic carbonates 346 using sodium thiophenoxide and alkyl thiolates 348 to give good-to-excellent selectivities for branched products 350 with excellent enantioselectivities. 

Displacements by thiophenoxide ion have an interesting possibility - the nucleophile can attack one electron at a time, transferring an electron to produce a thiophenoxy radical while reductively cleaving the electrophile to form an alkyl radical. Then the two radicals, in a solvent cage, can couple (Fig. 1.23). In an exploration of this process, called the SET mechanism, we used thiophenoxide with the sodium salt of p-carboxybenzyl iodide, and with the corresponding mesylate. We saw that there was a large acceleration by added ethanol in the iodide case, but not with the mesylate. We proposed that in the iodide displacement this reflected the conversion of thiophenoxide ion, with its delocalized charge, into the much more hydrophobic thiophenoxy radical at the transition state. Other evidence as well supported the SET mechanism. The carbon-iodine bond is more easily reductively cleaved than is the carbon-mesylate bond. 

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