(2R,4R)-2-benzyl-4-(tert-butoxycarbonylmethyl)-1-(p-toluenesulfonyl)piperidine | 767288-31-3

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 哌啶类
• 英文名称: (2R,4R)-2-benzyl-4-(tert-butoxycarbonylmethyl)-1-(p-toluenesulfonyl)piperidine
• 英文别名: tert-butyl 2-[(2R,4R)-2-benzyl-1-(4-methylphenyl)sulfonylpiperidin-4-yl]acetate
• CAS: 767288-31-3
• 化学式: C₂₅H₃₃NO₄S
• 分子量: 443.607
• InChiKey: JQGSCONOCFJKBS-YADHBBJMSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  5
• 重原子数：
  31
• 可旋转键数：
  8
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.48
• 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：

  (2R,4R)-2-benzyl-4-(tert-butoxycarbonylmethyl)-1-(p-toluenesulfonyl)piperidine 在 氢气 作用下， 生成 [(2R,4R)-2-Benzyl-1-(toluene-4-sulfonyl)-piperidin-4-yl]-acetic acid
  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 (7S)-(2Z)-6-aza-7-benzyl-8-hydroxy-6-(p-toluenesulfonyl)oct-2-enoate 在 偶氮二异丁腈 、 三正丁基氢锡 、 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 (2R,4R)-2-benzyl-4-(tert-butoxycarbonylmethyl)-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

文献信息

• Tris(trimethylsilyl)silane: an unprecedented enhancement in the diastereoselectivity of radical cyclisations to give 2,4-disubstituted piperidines
  作者：Lucile A. Gandon、Alexander G. Russell、John S. Snaith

  DOI：10.1039/b409714a

  日期：——

  Cyclisation of bromides 4a–f mediated by tributyltin hydride affords predominantly the trans piperidines 5a–f with modest diastereomeric ratios, while cyclisation with tris(trimethylsilyl)silane affords the same products with diastereomeric ratios of up to 99 : 1.

  由三丁基锡氢化物介导的溴化物4a–f的环化主要生成反式哌啶5a–f，具有适中的非对映体比，而与三（甲基硅基）硅烷的环化则生成相同的产物，非对映体比高达99 : 1。