tert-butyl (E)-(S)-6-aza-8-bromo-7-phenyl-6-(p-toluenesulfonyl)oct-2-enoate | 903516-45-0

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: tert-butyl (E)-(S)-6-aza-8-bromo-7-phenyl-6-(p-toluenesulfonyl)oct-2-enoate
• 英文别名: tert-butyl (E)-5-[[(1S)-2-bromo-1-phenylethyl]-(4-methylphenyl)sulfonylamino]pent-2-enoate
• CAS: 903516-45-0
• 化学式: C₂₄H₃₀BrNO₄S
• 分子量: 508.476
• InChiKey: TXFZPWJNINFZMW-QWDXWUACSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  5.3
• 重原子数：
  31
• 可旋转键数：
  11
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.38
• 拓扑面积：
  72.1
• 氢给体数：
  0
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  tert-butyl (E)-(S)-6-aza-8-bromo-7-phenyl-6-(p-toluenesulfonyl)oct-2-enoate 在 偶氮二异丁腈 、 三正丁基氢锡 作用下， 生成 (2R,4R)-4-(tert-butoxycarbonylmethyl)-2-phenyl-1-(p-toluenesulfonyl)piperidine 、 (2R,4S)-4-(tert-butoxycarbonylmethyl)-2-phenyl-1-(p-toluenesulfonyl)piperidine
  参考文献：
  名称：

  Synthesis of 2,4-Disubstituted Piperidines via Radical Cyclization:  Unexpected Enhancement in Diastereoselectivity with Tris(trimethylsilyl)silane

  摘要：

  [GRAPHICS]A novel approach to 2,4-disubstituted piperidines is reported, involving the radical cyclization of 7-substituted-6-aza-8-bromooct-2-enoates. Cyclization with tributyltin hydride affords the trans piperidines with trans/cis diastereomeric ratios ranging typically from 3:1 to 6:1. Cyclization with tris( trimethylsilyl)silane affords the same products with diastereomeric ratios of up to 99: 1 in certain cases. The enhancement in diastereoselectivity results from the selective rearrangement of the minor stereoisomer through a cascade process involving radical cyclization to the piperidine radical, 1,5-radical translocation, and attack of the translocated radical onto the sulfonamide with extrusion of SO2 in a Smiles-type rearrangement. Slower trapping of the piperidine radical by tris(trimethylsilyl) silane compared to tributyltin hydride accounts for the occurrence of the rearrangement cascade in the former case.

  DOI：

  10.1021/jo060495w
• 作为产物：
  描述：

  tert-butyl (S)-6-aza-8-hydroxy-7-phenyl-6-(p-toluenesulfonyl)oct-2-enoate 在 三乙胺 、 lithium bromide 作用下， 以 四氢呋喃 、 二氯甲烷 为溶剂， 反应 49.0h， 生成 tert-butyl (E)-(S)-6-aza-8-bromo-7-phenyl-6-(p-toluenesulfonyl)oct-2-enoate
  参考文献：
  名称：

  Synthesis of 2,4-Disubstituted Piperidines via Radical Cyclization:  Unexpected Enhancement in Diastereoselectivity with Tris(trimethylsilyl)silane

  摘要：

  [GRAPHICS]A novel approach to 2,4-disubstituted piperidines is reported, involving the radical cyclization of 7-substituted-6-aza-8-bromooct-2-enoates. Cyclization with tributyltin hydride affords the trans piperidines with trans/cis diastereomeric ratios ranging typically from 3:1 to 6:1. Cyclization with tris( trimethylsilyl)silane affords the same products with diastereomeric ratios of up to 99: 1 in certain cases. The enhancement in diastereoselectivity results from the selective rearrangement of the minor stereoisomer through a cascade process involving radical cyclization to the piperidine radical, 1,5-radical translocation, and attack of the translocated radical onto the sulfonamide with extrusion of SO2 in a Smiles-type rearrangement. Slower trapping of the piperidine radical by tris(trimethylsilyl) silane compared to tributyltin hydride accounts for the occurrence of the rearrangement cascade in the former case.

  DOI：

  10.1021/jo060495w