2-bromo-2,5-dihydrothiophene-1,1-dioxide | 30129-88-5

• 分子结构分类: 有机化合物 - 有机杂环化合物
• 英文名称: 2-bromo-2,5-dihydrothiophene-1,1-dioxide
• 英文别名: 2-Brom-3,4-dehydrosulfolan；Bromo-sulpholene；2-bromo-2,5-dihydrothiophene 1,1-dioxide
• CAS: 30129-88-5
• 化学式: C₄H₅BrO₂S
• 分子量: 197.052
• InChiKey: IRESEMZBLLCRDB-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  0.7
• 重原子数：
  8
• 可旋转键数：
  0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.5
• 拓扑面积：
  42.5
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  2-bromo-2,5-dihydrothiophene-1,1-dioxide 在 palladium on activated charcoal 氢气 作用下， 以 甲醇 为溶剂， 25.0 ℃ 、3.0 MPa 条件下， 反应 12.0h， 以25%的产率得到2-bromosulfolane
  参考文献：
  名称：

  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

  摘要：

  At low temperature and in the presence of CF3COOH, SO2 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 + SO2 reversible arrow 9d + 10d led to Delta H-r = -7.0 +/- 0.3 kcal/mol, Delta S-r = -42 +/- 3 cal . mol(-1) . K-1. At 20 degrees C, 8d underwent a slow cheletropic addition with SO2 giving 2-acetoxysulfolene (11d, Delta Hr congruent to -11.5 kcal/mol), the structure of which was established by single-crystal X-ray diffraction studies. (E)-Chloro (8e) and (E)-bromobutadiene (8f) did not undergo Diels-Alder additions with SO2, even in the presence of protic or Lewis acid promoters. Low yields of 2-chloro- (11e) and 8-bromosulfolene (11f) were obtained at 20 degrees 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 SO2 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 8-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 8-acetoxy- (11d) and 2-chlorosulfolene (11e) compared with their cycloaddents is attributed to repulsive interactions between the SO2 moieties and the 2-substituents. The Alder endo mode of [4 + 2] cycloaddition of SO2 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 reversible arrow 9X, 10X reversible arrow 10X. In general, the conformers 9X, 10X with pseudoaxial S=O group are preferred (conformational anomeric effect of the sulfinate moiety). Repulsive interactions between pseudoaxial S=O and polar cis-6-substituents (e.g.: X = OMe, OAc) in 9X may render conformers 9X (with the S-O 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).

  DOI：

  10.1021/jo981679g
• 作为产物：
  描述：

  1-bromo-1,3-butadiene 在 二氧化硫 作用下， 反应 12.0h， 以11%的产率得到2-bromo-2,5-dihydrothiophene-1,1-dioxide
  参考文献：
  名称：

  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

  摘要：

  At low temperature and in the presence of CF3COOH, SO2 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 + SO2 reversible arrow 9d + 10d led to Delta H-r = -7.0 +/- 0.3 kcal/mol, Delta S-r = -42 +/- 3 cal . mol(-1) . K-1. At 20 degrees C, 8d underwent a slow cheletropic addition with SO2 giving 2-acetoxysulfolene (11d, Delta Hr congruent to -11.5 kcal/mol), the structure of which was established by single-crystal X-ray diffraction studies. (E)-Chloro (8e) and (E)-bromobutadiene (8f) did not undergo Diels-Alder additions with SO2, even in the presence of protic or Lewis acid promoters. Low yields of 2-chloro- (11e) and 8-bromosulfolene (11f) were obtained at 20 degrees 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 SO2 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 8-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 8-acetoxy- (11d) and 2-chlorosulfolene (11e) compared with their cycloaddents is attributed to repulsive interactions between the SO2 moieties and the 2-substituents. The Alder endo mode of [4 + 2] cycloaddition of SO2 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 reversible arrow 9X, 10X reversible arrow 10X. In general, the conformers 9X, 10X with pseudoaxial S=O group are preferred (conformational anomeric effect of the sulfinate moiety). Repulsive interactions between pseudoaxial S=O and polar cis-6-substituents (e.g.: X = OMe, OAc) in 9X may render conformers 9X (with the S-O 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).

  DOI：

  10.1021/jo981679g