((2S,4R,6S)-4,6-Dimethyl-[1,3]dithian-2-yl)-diphenyl-phosphane | 135267-60-6

• 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: ((2S,4R,6S)-4,6-Dimethyl-[1,3]dithian-2-yl)-diphenyl-phosphane
• CAS: 135267-60-6
• 化学式: C₁₈H₂₁PS₂
• 分子量: 332.47
• InChiKey: HZTXXRZEIHDSCE-JLVBRIDZSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  5.05
• 重原子数：
  21.0
• 可旋转键数：
  3.0
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.33
• 拓扑面积：
  0.0
• 氢给体数：
  0.0
• 氢受体数：
  2.0

反应信息

• 作为产物：
  描述：

  [(4S,6R)-4,6-dimethyl-1,3-dithian-2-yl]-methylsulfanyl-diphenylphosphanium;trifluoromethanesulfonate 在 三(二甲胺基)膦 作用下， 以 二氯甲烷-D2 为溶剂， 生成 ((2R,4S,6R)-4,6-Dimethyl-[1,3]dithian-2-yl)-diphenyl-phosphane 、 ((2S,4R,6S)-4,6-Dimethyl-[1,3]dithian-2-yl)-diphenyl-phosphane
  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

文献信息

• Sulfur-carbon phosphorus anomeric interactions. 9. Effect of the coordination at phosphorus in the conformational equilibria of 2-P-substituted-1,3-dithianes
  作者：Eusebio Juaristi、Miguel A. Aguilar

  DOI：10.1021/jo00020a039

  日期：1991.9

  The conformational energies (A values) of the (diphenylphosphinyl)borane and diphenylphosphinyl groups were determined by multinuclear (H-1, C-13, P-31) NMR analysis of mobile (cis-4-phenylcyclohexyl)diphenylphosphine-borane, as well as the corresponding phosphine, and conformationally fixed models. The equatorial preferences observed are -DELTA-G-degrees(P(BH3)Ph2) = 3.3 kcal/mol and -DELTA-G-degrees(PPh2) = 1.8 kcal/mol. The conformational preference of these groups in the 1,3-dithian-2-yl ring were also determined by NMR analysis: -0.1 and -0.3 kcal/mol, respectively. The slight predominance of the equatorial isomers reflects nonetheless the influence of substantial S-C-P(BH3) and S-C-P: anomeric interactions, worth 1.8 and 1.0 kcal/mol, respectively. Evaluation of these values, together with previous data obtained for S-C-P(O) and S-C-P(S) systems, supports the participation of endo and exo hyperconjugative interactions, although the participation of 3p-3d electron donation among the sulfur and phosphorus atoms could also account for the results. Alternative rationalizations that have been considered to account for the strong S-C-P(O) anomeric effect appear now to play a minor role in the conformational equilibria of 2-P-substituted 1,3-dithianes.