5,5-Dimethyl-2--1,3-dithiane | 110466-74-5

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 二噻烷
• 英文名称: 5,5-Dimethyl-2--1,3-dithiane
• 英文别名: 5,5-Dimethyl-2-[diphenyl(thiophosphinoyl)]-1,3-dithiane；(5,5-Dimethyl-1,3-dithian-2-yl)(diphenyl)sulfanylidene-lambda~5~-phosphane；(5,5-dimethyl-1,3-dithian-2-yl)-diphenyl-sulfanylidene-λ5-phosphane
• CAS: 110466-74-5
• 化学式: C₁₈H₂₁PS₃
• 分子量: 364.536
• InChiKey: HLZRCUIKEGWNHS-UHFFFAOYSA-N

物化性质

• 熔点：
  181.4-183.3 °C
• 沸点：
  495.9±55.0 °C(Predicted)
• 密度：
  1.24±0.1 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  6.7
• 重原子数：
  22
• 可旋转键数：
  3
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.33
• 拓扑面积：
  82.7
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  5,5-Dimethyl-2--1,3-dithiane 在 三(二甲胺基)膦 作用下， 以 二氯甲烷-D2 为溶剂， 反应 0.57h， 生成 (5,5-Dimethyl-1,3-dithian-2-yl)-methyl-diphenylphosphanium;trifluoromethanesulfonate
  参考文献：
  名称：

  Synthesis and Conformational Behavior of 2-Phosphonio- and 2-Phosphinyl-1,3-dithianes. Operation of the Generalized Anomeric Effect in the S-C-P+ System

  摘要：

  A stereoselective preparation of various 2-phosphinyl- and 2-phosphonio-1,3-dithianes by desulfurization of the appropriate 2-thiophosphoryl-1,3-dithianes was described. The structure of the title compounds was studied by means of H-1, C-13, and P-31 NMR methods. Configurational assignments were also based on chemical correlation and X-ray structure determination. Both the NMR studies of conformationally labile models and equilibration of diastereomeric compounds showed an increased preference of the phosphinyl and phosphonium groups for the axial orientation. Magnitude of the anomeric effect found varies in the range from ca. 6 kJ/mol in phosphines to more than 10 kJ/mol in phosphonium salts. The anomeric effect could stem from the n(s)-sigma*(c-p) hyperconjugative interaction. If phenyl groups are connected with phosphorus, overlap repulsion involving lone electron pairs of the endocyclic sulfur atoms and pi-electrons of phenyl rings should also be taken into account. The reverse anomeric effect was not observed. No manifestation of the exo anomeric effect in 2-phosphinyl-1,3-dithianes was found.

  DOI：

  10.1021/jo00121a043
• 作为产物：
  描述：

  isopropyl diphenylphosphinite 在 N-氯代丁二酰亚胺 、 tetraphosphorus decasulfide 、 N,N-二乙基苯胺 作用下， 以 苯 为溶剂， 反应 18.33h， 生成 5,5-Dimethyl-2--1,3-dithiane
  参考文献：
  名称：

  Conformational Preference in 1,3-Dithianes Containing 2-Phosphoryl, -(thiophosphoryl), and -(selenophosphoryl) groups. Chemical and Crystallographic Implications of the Nature of the Anomeric Effect

  摘要：

  The operation of the anomeric effect in all the title compounds studied was found. The magnitude of the anomeric effect was found to be larger than 10 kJ/mol. Crystallographic, spectroscopic, and thermodynamic data suggest that the n(S)-sigma*(C-P) hyperconjugative interaction is one of the factors responsible for the anomeric effect. The second interaction stabilizing the axial position of phosphorus can be P=Y...H(4 or 6) hydrogen bond formation. Some other interactions are also possible, namely sigma(C(4,6)-S)-sigma*(C(2)-P) (preferring the equatorial position of phosphorus) and sigma(C(4,6)-S)-pi(P=Y) hyperconjugations and the n(S)-n(Y) repulsions. The latter interaction was also proposed as MO counterpart of lone pair-lone pair repulsions suggested by molecular mechanics calculations. It was proved that various conformation probes can afford different equilibrium constants, if weighted average method and conformationally fixed models are applied. Most of the physical quantities are dependent on the alkyl substitution in the 1,3-dithiane ring. Thus, the relevant procedure for the selection of conformational probe was presented. Since the gamma-effect value in C-13 NMR spectra was found to be very sensitive to the position of a substituent connected with the anomeric carbon atom of 1,3-dithianes, it was applied as a conformational probe. A long range (4)J(C-P) coupling constant in the C-13 NMR spectra and P-31 spin-lattice T-1(DD) relaxation times suggest the existence of close contact(s) between a heteroatom Y(Y=O,S,Se) connected with the axial phosphorus P=Y and axial protons H(4,6) in the 1,3-dithiane ring. Crystallographic data show that the distance from Y to one of these protons is usually much smaller than to the other one and smaller than the sum of H,Y van der Waals radii. The possibility of H..Y hydrogen bond formation is discussed.

  DOI：

  10.1021/jo00086a016