5,7-dichlorobenzisoxazole | 86013-72-1

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 苯并异恶唑
• 英文名称: 5,7-dichlorobenzisoxazole
• 英文别名: 5,7-dichloro-benzo[d]isoxazole；5,7-dichloro-benz[d]isoxazole；5,7-Dichlor-benz[d]isoxazol；5,7-Dichloro-1,2-benzoxazole
• CAS: 86013-72-1
• 化学式: C₇H₃Cl₂NO
• 分子量: 188.013
• InChiKey: YYLFAEIPUCYYML-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3
• 重原子数：
  11
• 可旋转键数：
  0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  26
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  5,7-dichlorobenzisoxazole 在 N-甲基吗啉 作用下， 以 水 为溶剂， 生成 3,5-二氯-2-羟基苯甲腈
  参考文献：
  名称：

  On the Magnitude and Specificity of Medium Effects in Enzyme-like Catalysts for Proton Transfer

  摘要：

  Medium effects are normally studied by comparing the rates of reactions in different solvents. However, medium effects at the active site of enzymes differ dramatically from bulk solvents, both in their diversity (the presence of more than one type of "solvent") and in their spatial arrangement. We describe medium effects in a simple catalytic system, obtained by systematic alkylation of a polymeric scaffold bearing amine groups to give synzymes that catalyze the Kemp elimination of benzisoxazoles with remarkable efficiency. Our analysis indicates that catalysis by these synzymes is driven primarily by specific, localized enzyme-like medium effects, and these effects seem to differ dramatically from the nonspecific medium effects (i.e., desolvation activation) exhibited by solvents. Ligand-binding studies indicate that the synzyme active sites provide localized microenvironments affording a combination of hydrophobic and apolar regions on one hand and dipolar, protic, and positively charged on the other. Such localized microenivronments are not available in bulk solvents. A Bronsted (leaving group) analysis indicates that, in comparison to solvent catalysis, the efficiency of synzyme catalysis shows little sensitivity to leaving group pK(a). We show that enzyme-like medium effects alone, in the absence of efficient positioning of the catalytic amine base relative to the substrate, can give rise to rate accelerations as high as 10(5), for both activated and nonactivated substrates. Supported by the accidental identification of active sites on the surfaces of noncatalytic proteins and the promiscuous activities found in many enzymes, our findings suggest that the interfaces of protein surfaces and their hydrophobic cores provide a microenvironment that is intrinsically active and may serve as a basis for further evolutionary improvements to give proficient and selective enzymes.

  DOI：

  10.1021/jo015723v
• 作为产物：
  描述：

  3,5-Dichloro-2-hydroxybenzaldehyde oxime 以82%的产率得到
  参考文献：
  名称：

  STOKKER, G., J. ORG. CHEM., 1983, 48, N 15, 2613-2615

  摘要：

  DOI：

文献信息

• Preparation of 1,2-benzisoxazoles from salicylaldoximes via trichloroacetyl isocyanate
  作者：Gerald Stokker

  DOI：10.1021/jo00163a042

  日期：1983.7
• Caronna; Palazzo, Gazzetta Chimica Italiana, 1959, vol. 89, p. 1009,1013
  作者：Caronna、Palazzo

  DOI：——

  日期：——
• Govindachari,T.R. et al., Indian Journal of Chemistry, 1968, vol. 6, p. 557 - 559
  作者：Govindachari,T.R. et al.

  DOI：——

  日期：——
• On the Magnitude and Specificity of Medium Effects in Enzyme-like Catalysts for Proton Transfer
  作者：Florian Hollfelder、Anthony J. Kirby、Dan S. Tawfik

  DOI：10.1021/jo015723v

  日期：2001.8.1

  Medium effects are normally studied by comparing the rates of reactions in different solvents. However, medium effects at the active site of enzymes differ dramatically from bulk solvents, both in their diversity (the presence of more than one type of "solvent") and in their spatial arrangement. We describe medium effects in a simple catalytic system, obtained by systematic alkylation of a polymeric scaffold bearing amine groups to give synzymes that catalyze the Kemp elimination of benzisoxazoles with remarkable efficiency. Our analysis indicates that catalysis by these synzymes is driven primarily by specific, localized enzyme-like medium effects, and these effects seem to differ dramatically from the nonspecific medium effects (i.e., desolvation activation) exhibited by solvents. Ligand-binding studies indicate that the synzyme active sites provide localized microenvironments affording a combination of hydrophobic and apolar regions on one hand and dipolar, protic, and positively charged on the other. Such localized microenivronments are not available in bulk solvents. A Bronsted (leaving group) analysis indicates that, in comparison to solvent catalysis, the efficiency of synzyme catalysis shows little sensitivity to leaving group pK(a). We show that enzyme-like medium effects alone, in the absence of efficient positioning of the catalytic amine base relative to the substrate, can give rise to rate accelerations as high as 10(5), for both activated and nonactivated substrates. Supported by the accidental identification of active sites on the surfaces of noncatalytic proteins and the promiscuous activities found in many enzymes, our findings suggest that the interfaces of protein surfaces and their hydrophobic cores provide a microenvironment that is intrinsically active and may serve as a basis for further evolutionary improvements to give proficient and selective enzymes.
• STOKKER, G., J. ORG. CHEM., 1983, 48, N 15, 2613-2615
  作者：STOKKER, G.

  DOI：——

  日期：——