- On the reactivity of indium(III) benzenechalcogenolates (chalcogen = sulfur and selenium) towards organyl halides for the synthesis of organyl phenyl chalcogenides
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The reactivity of indium(III) benzenechalcogenolates (chalcogen = sulfur, selenium) towards organyl halides (organyl = alkyl, allyl, benzyl, acyl) was examined. A practical one-pot method to prepare organyl phenyl chalcogenides indium metal and diphenyl dichalcogenide was found. The coupling is fairly broad in scope and generally works better organyl halides capable to produce stable carbocations.
- Peppe, Clovis,Borges De Castro, Lierson
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experimental part
p. 678 - 683
(2009/10/30)
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- Aryl 1-chloroalkyl sulfoxides as acyl anion equivalents: A new synthesis of vinyl sulfides, ketones, and diketones from aryl 1-chloroalkyl sulfoxides and α,ω-dichloro-α,ω-disulfinylalkanes
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Treatment of aryl α-chloroalkyl sulfoxides, which were synthesized from aryl 1-chloroalkyl sulfoxides by alkylation with iodoalkanes, with trifluoroacetic anhydride and NaI in acetone at low temperature afforded vinyl sulfides in high yields. The vinyl sulfides were converted to ketones by hydrolysis with HClO4 in refluxing 1,4-dioxane in good yields. In this procedure, the lithiated aryl 1-chloroalkyl sulfoxides acted as acyl anion equivalents. The procedure was extended to a synthesis of α,ω-diketones starting from α,ω-dichloro-α,ω-disulfinylalkanes. The procedure was found to work well when the length of the carbon chain of the α,ω-disulfinylalkanes is longer than four, and the yields of the diketones were found to be somewhat variable (60-80%).
- Satoh, Tsuyoshi,Taguchi, Daisaku,Suzuki, Chihiro,Fujisawa, Satoshi
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p. 493 - 500
(2007/10/03)
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- 1H- And13C-NMR and electron ionization (EI) mass spectrometric study of o- And p-substituted 1,n-diarylsulfonylalkanes, XC6H4so2(CH2)nso 2C6H4X (n = 2-5, 8, 10)+
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1,n-Diphenylsulfonylalkanes, PhSO2(CH2)nSO2Ph (n =2-5, 8, 10) and their o- or p-Cl or -OMe derivatives were prepared and their 1H- and 13C-NMR and EI mass spectra recorded and analyzed. The chemical shifts of the aliphatic α- and β-carbons showed a clear dependence on the o-aryl substitution, the o-Cl being the most shielding for both. Clear low-field effects were found also for the aliphatic α-protons in o-Cl and o-OMe derivatives. In case of p-OMe derivatives a palpable shielding of the aliphatic α-protons was also found similarly to the β-protons of the o-OMe derivatives. Characteristic mass spectrometric fragmentations which reflected both the influence of the aryl substitution and the length of the alkyl chain were observed and sometimes also exhibited the sulphinic acid rearrangement.
- Pihlaja, Kalevi,Kabilan, Senthamaraikannan,Ganapathi, Athiappan,Sankar, Punnaivanam
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p. 601 - 612
(2007/10/03)
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- Dipole Moments and UV Spectra of some Long-chain Molecules
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About one hundred compounds with long-chain molecular structure have been prepared (most of them are new).The dipole moments of four α,ω-bis(p-methoxyphenylthio)alkanes and five α,ω-bis(p-methoxyphenylsulphonyl)alkanes have been determined to find the effect of chain-length.In the case of sulphones, the observed values are compared with the values calculated for free rotation around all bonds intervening the end dipoles.The uv spectra of some 1,2-(distyrylsulphonyl)ethanes, and a number of α,ω-bis(arylsulphonyl)- and α,ω-bis(aryloxy)alkanes have been recorded to examine the applicability of the principle of chromophore additivity.
- Baliah, V.,Aparajithan, K.
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p. 255 - 259
(2007/10/02)
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- One-Electron Chemical Reductions of Phenylalkylsulfonium Salts
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Twenty-two arylalkylsulfonium salts have been reduced with potassium in graphite in tetrahydrofuran and the sulfide products identified.Two trialkylsulfonium salts did not reduce under these conditions.Comparison of the sulfides from a series of monophenylalkylsulfonium salts reveals a leaving-group propensity of benzyl > secondary > primary > methyl > phenyl in a ratio of 28:(6.0 +/- 0.3):1.0:(0.53 +/- 0.09): 0.05.The cleavage ratio is shown to be independent of the electron source and the homogeneity of heterogeneity of the reaction in two cases.Multiplicative transitivity of the above ratios is not observed, although the same qualitative order is found for other comparisons.These results are interpreted in terms of the initial formation of a ?-ligand radical anion sulfonium cation, which undergoes cleavage to a carbon radical and a sulfide.This appears to be the first evidence for this type of structure in a sulfur system.Leaving-group propensities different from the above order are observed in reductions of diphenylsulfonium and benzo-fused sulfonium salts, and rationales are offered.The intermediates in these reactions appear to be different from those involved in radical additions to, or displacements on, sulfur.
- Beak, Peter,Sullivan, Thomas A.
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p. 4450 - 4457
(2007/10/02)
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