Chlorination of α-sulfonyl carbanions with hexachloroethane

Kattenberg, J.; Waard, E.R. de; Huisman, H. O.

doi:10.1016/0040-4020(73)80249-2

Cited by 31 publications

(4 citation statements)

References 25 publications

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“…This suggests that 1-chloro and 1-bromo substitutions of butadiene render the hetero-Diels-Alder additions too slow or that they destabilize the corresponding sultines, making them invisible under our conditions. The structure of 11e was confirmed by chemical correlation with 2-chlorosulfolane 21 and by X-ray diffraction studies (see Supporting Information). The structure of 11f was confirmed by catalytical hydrogenation (H 2 , 30 atm) that gave 2-bromosulfolane, a compound identical with that obtained by bromination (Br 2 /Ph-H) of sulfolane treated with 1.2 equiv of EtMgBr.…”

Section: Resultsmentioning

confidence: 87%

“…Sulfolene 11e (88 mg, 0.6 mmol) in CH 2 Cl 2 (3 mL) was pressured with H 2 (1 atm) and stirred at 20 °C for 1 h in the presence of 10% Pd/C (20 mg). After filtration (Celite) and solvent evaporation, flash chromatography on silica gel (CH 2 Cl 2 ) gave 53 mg (60%) of a colorless oil identical (spectral data) with a sample of 2-chlorosulfolane prepared from sulfolane according to Kattenberg …”

Section: Methodsmentioning

confidence: 99%

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Competition between Hetero-Diels−Alder and Cheletropic Addition of Sulfur Dioxide. Theoretical and Experimental Substituent Effects on the Relative Stability of 3,6-Dihydro-1,2-oxathiin-2-oxides (Sultines) and 2,5-Dihydrothiophene-1,1-dioxides (Sulfolenes). Anomeric Effects in Sultine and 6-Substituted Derivatives

et al. 1998

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At low temperature and in the presence of CF 3 COOH, SO 2 undergoes Diels-Alder additions with (E)-1-acetoxybutadiene (8d) giving a 1:10 mixture of diastereomeric 6-acetoxysultines (9d + 10d). The Van't Hoff plot for equilibria 8d + SO 2 a 9d + 10d led to ∆H r ) -7.0 ( 0.3 kcal/mol, ∆S r ) -42 ( 3 cal‚mol -1 ‚K -1 . At 20 °C, 8d underwent a slow cheletropic addition with SO 2 giving 2-acetoxysulfolene (11d, ∆H r = -11.5 kcal/mol), the structure of which was established by singlecrystal X-ray diffraction studies. (E)-Chloro (8e) and (E)-bromobutadiene (8f) did not undergo Diels-Alder additions with SO 2 , even in the presence of protic or Lewis acid promoters. Low yields of 2-chloro-(11e) and 2-bromosulfolene (11f) were obtained at 20 °C. The structure of 11e was confirmed by single-crystal X-ray diffraction. The potential energy hypersurfaces of the Diels-Alder and cheletropic additions of SO 2 to butadiene (8a), (E)-piperilene (8b), (E)-1-methoxy-(8c), (E)-1-acetoxy-(8d), and (E)-1-chlorobutadiene (8e) were studied by ab initio quantum calculations at the MP2/6-31G* level. In agreement with the experiment, 6-substituted sultines 9X and 10X were less stable than the corresponding 2-substituted sulfolenes 11X for X ) Me, OAc, Cl. With X ) OMe, the two diastereomeric 6-methoxysultines (9c, 10c) and 2-methoxysulfolene (11c) were calculated to have similar stabilities. This is attributed to a stabilizing thermodynamic anomeric effect or gem-sulfinate/methoxy disubstitution effect in 9c, 10c. Such effects were not detected for sulfinate/acetoxy (9d, 10d) and sulfinate/chloro (9e, 10e) disubstitutions. The relative instability of 2-acetoxy-(11d) and 2-chlorosulfolene (11e) compared with their cycloaddents is attributed to repulsive interactions between the SO 2 moieties and the 2-substituents. The Alder endo mode of [4 + 2] cycloaddition of SO 2 is predicted to be faster than the "anti-Alder mode" of additions for dienes 8X, X ) Me, OMe, OAc, Cl. The resulting diastereomeric sultines 9X and 10X, respectively, exist as equilibria (energy barrier: ca. 5-6 kcal/mol) of two conformers 9X a 9′X, 10X a 10′X. In general, the conformers 9X, 10X with pseudoaxial SdO group are preferred (conformational anomeric effect of the sulfinate moiety). Repulsive interactions between pseudoaxial SdO and polar cis-6substituents (e.g.: X ) OMe, OAc) in 9X may render conformers 9′X (with the SdO and 6-X groups in pseudoequatorial positions) as stable as conformers 9X. The calculations predict the existence of conformational anomeric effects of 2-3 kcal/mol for the gem-sulfinate/methoxy (9c, 10′c) and gem-sulfinate/acetoxy disubstitution (9d, 10′d).

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Section: Resultsmentioning

confidence: 87%

Section: Methodsmentioning

confidence: 99%

Competition between Hetero-Diels−Alder and Cheletropic Addition of Sulfur Dioxide. Theoretical and Experimental Substituent Effects on the Relative Stability of 3,6-Dihydro-1,2-oxathiin-2-oxides (Sultines) and 2,5-Dihydrothiophene-1,1-dioxides (Sulfolenes). Anomeric Effects in Sultine and 6-Substituted Derivatives

et al. 1998

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“…Soco Jpn, 1980, 213027. 24 Kattenberg Os autores empregaram este sistema também em reações de alquilação, obtendo, em todos os casos, produtos monoalquilados em rendimentos entre 59 -100 %.…”

Section: Esquemaunclassified

Reações de α-sulfonil carbânions: alquilação e sulfenilação de alguns α-sulfonil tioésteres. Descarboxilação alquilativa dos ácidos α-fenilsulfonil-α-fenilpropanóicos racêmico e opticamente ativo

Neves¹

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“…In the first case the reaction results in the formation of a neutral compound; in the second case the result is the formation of onium (quasi-onium) ion. The most investigated processes are halogenation including the halogenation of olefins, 101 ketones, 102 esters, 103,104 sulfones, 105,106 nitriles, 107, 108 phosphates, 109 diarylmethanes, 110 and N-substituted amides 111 and imides 112 via a halogenophilic pathway by the treatment with appropriate halides. A lot of common organic compound could be utilized as a source of halogen, including CCl4, CBr4, 1,2-dibromoethane, hexachloroethane, 2,3-dibromo-2,3-dimethylbutane, and hexachloroacetone.…”

Section: Application Of X Transfer In Organic Synthesismentioning

confidence: 99%

Asymmetric nucleophilic substitutions to construct all-carbon quaternary stereocenters under PTC conditions

Ban¹

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Chlorination of α-sulfonyl carbanions with hexachloroethane

Cited by 31 publications

References 25 publications

Reações de α-sulfonil carbânions: alquilação e sulfenilação de alguns α-sulfonil tioésteres. Descarboxilação alquilativa dos ácidos α-fenilsulfonil-α-fenilpropanóicos racêmico e opticamente ativo

Asymmetric nucleophilic substitutions to construct all-carbon quaternary stereocenters under PTC conditions

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