9,10-diiodo-2-nitro-9,10-dihydro-9,10-ethanoanthracene | 165054-05-7

• 分子结构分类: 有机化合物 - 苯类化合物 - 蒽
• 英文名称: 9,10-diiodo-2-nitro-9,10-dihydro-9,10-ethanoanthracene
• 英文别名: 1,8-Diiodo-4-nitrotetracyclo[6.6.2.02,7.09,14]hexadeca-2(7),3,5,9,11,13-hexaene
• CAS: 165054-05-7
• 化学式: C₁₆H₁₁I₂NO₂
• 分子量: 503.078
• InChiKey: URYKUHMJIHTDPH-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  5.6
• 重原子数：
  21
• 可旋转键数：
  0
• 环数：
  5.0
• sp3杂化的碳原子比例：
  0.25
• 拓扑面积：
  45.8
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  4-甲基苯硫酚钠 、 9,10-diiodo-2-nitro-9,10-dihydro-9,10-ethanoanthracene 以 二甲基亚砜 为溶剂， 反应 0.5h， 以73%的产率得到2-nitro-9,10-bis(p-tolylthio)-9,10-dihydro-9,10-ethanoanthracene
  参考文献：
  名称：

  Substitution of Bridgehead Halogens by a Free-Radical Electron-Transfer Mechanism

  摘要：

  1-溴-7-硝基-和1-溴-6-硝基-1,4-甲基萘（2）和（3），以及9-溴-2-硝基，10-溴-2-硝基，9,10-二溴-2-硝基和9,10-二碘-2-硝基-9,10-乙烯基-9,10-二氢蒽（4）-（7）的反应。分别与对甲苯硫醇（1）的钠盐反应，形成了被证明是通过SRN1或相关的自由基链机制形成的取代产物。在盐（1）与含有溴在桥头位置的化合物（2）-（5）之间相对缓慢的取代反应中。其中溴位于对芳基硝基的间位或对位，离去基团为对芳基硝基的异构体的取代速率略高于相应的对位取代体。在化合物（6）和（7）中，卤素位于相同分子中相对于芳基硝基的桥头位置的间位或对位。在二溴化物（6）与硫醇酸盐（1）的反应中，取代较慢，并且在间位于硝基的芳基桥头位置比相应的对位芳基位置更快地发生。相反，二碘化物（7）与硫醇酸盐（1）的反应产生的取代产物比二溴化物（6）的相应反应更快形成，而且取代选择性被颠倒，取代更容易发生在对硝基的芳基桥头位置，而不是相应的间位芳基位置。对于化合物（2）-（6）与盐（1）的反应确定的间位和对位取代产物比率在1.15-2.5:1的范围内，而（7）与相同亲核试剂的反应得到了1:2:3的间位与对位比率。这些比率不仅彼此之间有所不同，而且与已知与相同亲核试剂发生SRN1取代反应的其他硝基芳基系统的反应性差异也不同。比较了桥头系统之间的取代选择性的差异，以及观察到的取代选择性取代速率的差异与其他简单硝基芳基卤化物。这些差异是根据将C-X键固定在桥头位置使其与硝基芳基平面正交的效应来解释的；这导致分子内电子转移速率常数的降低，对这些反应的详细整体机制产生重要影响。

  DOI：

  10.1071/ch9960581
• 作为产物：
  描述：

  9,10-二碘蒽 在 硝酸 作用下， 以 乙酸酐 、 甲苯 为溶剂， 反应 48.08h， 生成 9,10-diiodo-2-nitro-9,10-dihydro-9,10-ethanoanthracene
  参考文献：
  名称：

  Reduction of Bridgehead Halogens by an Intramolecular Electron Transfer Radical Mechanism

  摘要：

  Reactions of 9,10-dibromo- and 9,10-diiodo-2-nitro-9,10-ethano-9,10-dihydroanthracene (10 and 11, respectively) with the tertiary carbanions, 1, 3, 5, and 7-9, proceed exclusively by reduction at the bridgehead with no substitution products being observed. It is proposed that the reduction process occurs by a radical chain mechanism including an intramolecular electron transfer step and beta-hydrogen abstraction from alkyl substituents on the participating carbanions. These ethanoanthracenes contain halogens at bridgehead positions that are meta- and para-benzylic relative to an aromatic nitro group, thus allowing the determination of the relative reactivities of the two benzylic sites within the same molecule. Quantitative studies on the reaction of 11 with sodium salts of 2-ethylmalononitrile and diethyl 2-ethylmalonate reveal that the reduction process is regioselective, with reduction occurring more readily at the benzylic bridgehead position para to the nitro group than at the corresponding meta-benzylic position. The ratio of meta:para reduction products, determined for the reaction of the diiodide 11 with several carbanions, was in the range 1:(1.6 +/- 0.2). This ratio contrasts with the differences in rate constants (approximately 2 orders of magnitude) determined for other nitrobenzylic systems, known to undergo S(RN)1 substitution reactions with the same nucleophiles. These differences in the ratio of rate constants of regioselective reduction compared with those observed for substitution reactions is discussed in terms of the C-X bond at a bridgehead position lying orthogonal to the plane of the nitroaryl group. As a result of this geometry, the rate of intramolecular electron transfer is significantly reduced and the ratio of para-benzylic to meta-benzylic reactivity differs only by a factor of less than 2.

  DOI：

  10.1021/jo00122a030

文献信息

• Substitution of Bridgehead Halogens by a Free-Radical Electron-Transfer Mechanism
  作者：MC Harsanyi、PA Lay、RK Norris、PK Witting

  DOI：10.1071/ch9960581

  日期：——

  The reactions of 1-bromo-7-nitro- and 1-bromo-6-nitro-1,4-methanonaphthalene (2) and (3), and 9-bromo-2-nitro, 10-bromo-2-nitro-, 9,10-dibromo-2-nitro- and 9,10-diiodo-2-nitro-9,10-ethano-9,10-dihydroanthracene (4)-(7). respectively, with the sodium salt (1) of p-toluenethiol gave substitution products that were shown to be formed by an SRN1 or a related radical chain mechanism. In the relatively slow substitution reactions of the salt (1) with compounds (2)-(5). That contain bromine at bridgehead positions that are either meta- or para-benzylic to an aromatic nitro group, the rates of substitution in the isomers where the leaving group was meta- benzylic to the aromatic nitro group were slightly greater than those for the corresponding para-benzylic isomer. In compounds (6)and (7) the halogens are at bridgehead positions that are either meta- or para-benzylic relative to an aromatic nitro group within the same molecule. In the case of the reaction of the dibromide (6) with the thiolate (1), substitution was slow and occurred more rapidly at the benzylic -bridgehead position meta to the nitro group than at the corresponding para-benzylic position. In contast , the reaction of the diiodide (7) with the thiolate (1) gave substitution products which formed more rapidly than in the corresponding reaction of the dibromide (6) and the regioselectivity was reversed, with substitution occurring more readily at the bridgehead position para-benzylic to the nitro group than at the corresponding meta- benzylic position. The ratio of meta to para substitution products, determined for the reactions of compounds (2)-(6) with the salt (1), were in the range 1.15-2.5:1, while the reaction of (7) with the same nucleophile afforded a meta-to-para ratio of 1:2:3. These ratios contrast not only with each other, but also with the differences in reactivities determined for other nitrobenzylic systems, which are known to undergo SRN1 substitution reactions with the same nucleophile. The differences in first, the regioselectivity of substitution between the bridgehead systems, and secondly, the differences in the observed rates of regioselective substitution are compared with other simple nitrobenzylic halides. These differences are rationalized in terms of the effect of fixing the C-X bond at a bridgehead position to be orthogonal with the plane of the nitroaromatic group; this results in a reduction of the rate constants of intramolecular electron transfer, with significant consequences on the detailed overall mechanism for these reactions.

  1-溴-7-硝基-和1-溴-6-硝基-1,4-甲基萘（2）和（3），以及9-溴-2-硝基，10-溴-2-硝基，9,10-二溴-2-硝基和9,10-二碘-2-硝基-9,10-乙烯基-9,10-二氢蒽（4）-（7）的反应。分别与对甲苯硫醇（1）的钠盐反应，形成了被证明是通过SRN1或相关的自由基链机制形成的取代产物。在盐（1）与含有溴在桥头位置的化合物（2）-（5）之间相对缓慢的取代反应中。其中溴位于对芳基硝基的间位或对位，离去基团为对芳基硝基的异构体的取代速率略高于相应的对位取代体。在化合物（6）和（7）中，卤素位于相同分子中相对于芳基硝基的桥头位置的间位或对位。在二溴化物（6）与硫醇酸盐（1）的反应中，取代较慢，并且在间位于硝基的芳基桥头位置比相应的对位芳基位置更快地发生。相反，二碘化物（7）与硫醇酸盐（1）的反应产生的取代产物比二溴化物（6）的相应反应更快形成，而且取代选择性被颠倒，取代更容易发生在对硝基的芳基桥头位置，而不是相应的间位芳基位置。对于化合物（2）-（6）与盐（1）的反应确定的间位和对位取代产物比率在1.15-2.5:1的范围内，而（7）与相同亲核试剂的反应得到了1:2:3的间位与对位比率。这些比率不仅彼此之间有所不同，而且与已知与相同亲核试剂发生SRN1取代反应的其他硝基芳基系统的反应性差异也不同。比较了桥头系统之间的取代选择性的差异，以及观察到的取代选择性取代速率的差异与其他简单硝基芳基卤化物。这些差异是根据将C-X键固定在桥头位置使其与硝基芳基平面正交的效应来解释的；这导致分子内电子转移速率常数的降低，对这些反应的详细整体机制产生重要影响。
• Reduction of Bridgehead Halogens by an Intramolecular Electron Transfer Radical Mechanism
  作者：Michael C. Harsanyi、Peter A. Lay、Robert K. Norris、Paul K. Witting

  DOI：10.1021/jo00122a030

  日期：1995.9

  Reactions of 9,10-dibromo- and 9,10-diiodo-2-nitro-9,10-ethano-9,10-dihydroanthracene (10 and 11, respectively) with the tertiary carbanions, 1, 3, 5, and 7-9, proceed exclusively by reduction at the bridgehead with no substitution products being observed. It is proposed that the reduction process occurs by a radical chain mechanism including an intramolecular electron transfer step and beta-hydrogen abstraction from alkyl substituents on the participating carbanions. These ethanoanthracenes contain halogens at bridgehead positions that are meta- and para-benzylic relative to an aromatic nitro group, thus allowing the determination of the relative reactivities of the two benzylic sites within the same molecule. Quantitative studies on the reaction of 11 with sodium salts of 2-ethylmalononitrile and diethyl 2-ethylmalonate reveal that the reduction process is regioselective, with reduction occurring more readily at the benzylic bridgehead position para to the nitro group than at the corresponding meta-benzylic position. The ratio of meta:para reduction products, determined for the reaction of the diiodide 11 with several carbanions, was in the range 1:(1.6 +/- 0.2). This ratio contrasts with the differences in rate constants (approximately 2 orders of magnitude) determined for other nitrobenzylic systems, known to undergo S(RN)1 substitution reactions with the same nucleophiles. These differences in the ratio of rate constants of regioselective reduction compared with those observed for substitution reactions is discussed in terms of the C-X bond at a bridgehead position lying orthogonal to the plane of the nitroaryl group. As a result of this geometry, the rate of intramolecular electron transfer is significantly reduced and the ratio of para-benzylic to meta-benzylic reactivity differs only by a factor of less than 2.