α-tert-butyl-4-methoxybenzyl methyl ether | 120236-48-8

• 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: α-tert-butyl-4-methoxybenzyl methyl ether
• 英文别名: 1-methoxy-4-(1-methoxy-2,2-dimethylpropyl)benzene
• CAS: 120236-48-8
• 化学式: C₁₃H₂₀O₂
• 分子量: 208.301
• InChiKey: RWTUCSQCWWSYMM-UHFFFAOYSA-N

物化性质

• 沸点：
  263.1±23.0 °C(Predicted)
• 密度：
  0.949±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  3.3
• 重原子数：
  15
• 可旋转键数：
  4
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.54
• 拓扑面积：
  18.5
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  α-tert-butyl-4-methoxybenzyl methyl ether 在 dioxide titanium 、 silver sulfate 作用下， 以 乙腈 为溶剂， 反应 1.0h， 以10%的产率得到1-(4-甲氧基苯基)-2,2-二甲基丙烷-1-酮
  参考文献：
  名称：

  二氧化钛在乙腈中诱导的α-烷基苄基甲基醚的光氧化脱烷基化

  摘要：

  在脱气的CH 3 CN中进行TiO 2敏化的α-烷基苄基甲基醚的光氧化反应，得到了预期的相应酮，而在充气介质中，相对于酮，以脱烷基化化合物（苯甲酸甲酯）为主要产物，或独家产品（当烷基为叔丁基时）。产物分析和分布以及相对反应性的定性估计表明，脱气CH 3中的机理CN与先前对非α-烷基化的苄基醚所假设的相同；特别地，羰基化合物应通过将苄基（通过阳离子的去质子化获得）氧化成相应的阳离子而形成。为了证明在充气介质中形成苯甲酸甲酯是合理的假设，即α-烷基-α-甲氧基苄基过氧自由基（由氧竞争性地攻击苄基获得）经历了脱烷基过程；特别地，该中间体作为叔过氧自由基可以形成二聚体，该二聚体演变成相应的氧自由基，从而通过β-断裂过程得到酯。通过评估酯/羰基（E / C）摩尔比与苄基自由基中间体的绝热电离电势之间的关系，可以证实在充气介质中提出的一般机理。为了评估介质异质性的影响，将E / C比数据与通过均相中的电子转移光敏[通过9

  DOI：

  10.1002/poc.991
• 作为产物：
  描述：

  1-methoxy-4-[(3R,4S)-4-(4-methoxyphenyl)-2,2,5,5-tetramethylhexan-3-yl]benzene 以34%的产率得到
  参考文献：
  名称：

  EICHIN, K. -H.;BECKHAUS, H. -D.;HELLMANN, S.;FRITZ, H.;PETERS, E. -M.;PET+, CHEM. BER., 1983, 116, N 5, 1787-1821

  摘要：

  DOI：

文献信息

• Photo-oxidative Fragmentation of Some alpha-Alkyl Substituted 4-Methoxybenzyl Alcohols and Methyl Ethers Sensitized by TiO2.
  作者：Enrico Baciocchi、Massimo Bietti、Marina I. Ferrero、Cesare Rol、Giovanni V. Sebastiani、George W. Francis、József Szúnyog、Bengt Långström

  DOI：10.3891/acta.chem.scand.52-0160

  日期：——

  The TiO2-catalyzed photo-oxidation of some alpha-alkyl substituted 4-methoxybenzyl alcohols and ethers [4-MeOPhCH(OR)Y] has been investigated in MeCN, in the presence of Ag2SO4. When Y=t-Bu, the intermediate radical cation undergoes exclusive C-alpha-H bond cleavage (leading to the corresponding ketone) if R = Me, but predominantly C-alpha-C-beta bond cleavage (leading to 4-MeOPhCHO) if R=H. The C-alpha-H bond cleavage path is also the major one when Y= i-Pr and R=H. For the substrates where Y=CH(OMe)Me or CH(OH)Me, exclusive C-C bond cleavage is observed when R is either H or Me. A similar situation holds when the photo-oxidations are carried out in the presence of oxygen, however a change in the outcome of the reaction has been observed for the substrates where R=Me and Y=t-Bu or CH(OMe)Me, which both form 4-MeOC6H4CO2Me as the exclusive product. These results are interpreted on the basis of the structural effects on the fragmentation reactions of the intermediate radical cations, the stability of the formed carbon radicals and carbocations, as well as the possible reactions of the former with oxygen.
• Kinetic and Product Studies on the Side-Chain Fragmentation of 1-Arylalkanol Radical Cations in Aqueous Solution: Oxygen versus Carbon Acidity
  作者：Enrico Baciocchi、Massimo Bietti、Steen Steenken

  DOI：10.1002/(sici)1521-3765(19990604)5:6<1785::aid-chem1785>3.0.co;2-0

  日期：1999.6.4

  A kinetic and product study of the side-chain fragmentation reactions of a series of 1-arylalkanol radical cations (4-MeOC6H4CH(OH)R.+) and some of their methyl ethers was carried out; the radical cations were generated by pulse radiolysis and gamma radiolysis in aqueous solution. The radical cations undergo side-chain fragmentation involving the C-alpha-H andior C-alpha-C-beta bonds, and their reactivity was studied both in acidic (pH14) and basic (pH 10-11) solution. At pH 4, the radical cations decay with first-order kinetics, and the exclusive reaction is C-alpha-H deprotonation for 1(.+) 2(.+), and 3(.+) (R = H, Me, and Et, respectively) but C-alpha-C-beta bond cleavage for 5(.+)-, 6(.+), and 7(.+) (R = tBu, CH(OH)Me, and CH(OMe)Me, respectively). Both types of cleavage are observed for 4(.+) (R = iPr). The radical cations of the methyl ethers 8(.+), 9(.+), and 10(.+) (R = H, Et, and iPr, respectively) undergo exclusive deprotonation, whereas C-C fragmentation predominates for 11(.+) (R = tBu). Large C-alpha deuterium kinetic isotope effects (4.5 and 5.0, respectively) were found for 1(.+) and its methyl ether 8(.+). Replacement of an alpha-OH group by OMe has a very small effect on the decay rate when the radical cation undergoes deprotonation, but a very large, negative effect in the case of C-C bond cleavage. It is suggested that hydrogen bonding of the alpha-OH group with the solvent stabilizes the transition state of the C-C bond fragmentation reaction but not that of the deprotonation process; however, other factors could also contribute to this phenomenon. The decay of the radical cations is strongly accelerated by HO-, and all the alpha-OH substituted radical cations react with HO- at a rate (approximate to 10(10) M-1 s(-1)) very close to the limit of diffusion control and independent of the nature of the bond that is finally broken in the process (C-H or C-C). The methyl ether 8(.+), which exclusively undergoes C-H bond cleavage, reacts significantly slower (by a factor of ca. 50) than the corresponding alcohol 1(.+). These data indicate that 1-arylalkanol radical cations, which display the expected carbon acidity in water, become oxygen acids in the presence of a strong base such as HO- and undergo deprotonation of the O-H group; diffusion-controlled formation of the encounter complex between HO- and the radical cation is the rate-determining step of the reaction. It is suggested that, within the complex, the proton is transferred to the base to give a benzyloxyl radical, either via a radical zwitterion (which undergoes intramolecular electron transfer) or directly (electron transfer coupled with deprotonation). The latter possibility seems more in line with the general base catalysis (beta approximate to 0.4) observed in the reaction of 5(.+), which certainly involves O-H deprotonation. The benzyloxyl radical can then undergo a beta C-C bond cleavage to form 4-methoxybenzaldehyde and R-. or a formal 1,2-H shift to form an alpha-hydroxybenzyl-type radical. The factors of importance in this carbon/oxygen acidity dichotomy are discussed.
• Photo-oxidative dealkylation of α-alkylbenzyl methyl ethers induced by titanium dioxide in acetonitrile
  作者：Marta Bettoni、Tiziana Del Giacco、Cesare Rol、Giovanni V. Sebastiani

  DOI：10.1002/poc.991

  日期：2006.1

  heterogeneity, the E/C ratio data were compared with those obtained from an electron-transfer photosensitised [by 9,10-dicyanoanthracene (DCA)] oxidation in a homogeneous phase. A significant confirmation of the mechanism, in both deaerated and aerated media, was obtained by the reaction performed from 4-methoxy-α-ethylbenzyl methyl ether (as a model) in the presence of H218O, sensitised by either TiO2

  在脱气的CH 3 CN中进行TiO 2敏化的α-烷基苄基甲基醚的光氧化反应，得到了预期的相应酮，而在充气介质中，相对于酮，以脱烷基化化合物（苯甲酸甲酯）为主要产物，或独家产品（当烷基为叔丁基时）。产物分析和分布以及相对反应性的定性估计表明，脱气CH 3中的机理CN与先前对非α-烷基化的苄基醚所假设的相同；特别地，羰基化合物应通过将苄基（通过阳离子的去质子化获得）氧化成相应的阳离子而形成。为了证明在充气介质中形成苯甲酸甲酯是合理的假设，即α-烷基-α-甲氧基苄基过氧自由基（由氧竞争性地攻击苄基获得）经历了脱烷基过程；特别地，该中间体作为叔过氧自由基可以形成二聚体，该二聚体演变成相应的氧自由基，从而通过β-断裂过程得到酯。通过评估酯/羰基（E / C）摩尔比与苄基自由基中间体的绝热电离电势之间的关系，可以证实在充气介质中提出的一般机理。为了评估介质异质性的影响，将E / C比数据与通过均相中的电子转移光敏[通过9
• EICHIN, K. -H.;BECKHAUS, H. -D.;HELLMANN, S.;FRITZ, H.;PETERS, E. -M.;PET+, CHEM. BER., 1983, 116, N 5, 1787-1821
  作者：EICHIN, K. -H.、BECKHAUS, H. -D.、HELLMANN, S.、FRITZ, H.、PETERS, E. -M.、PET+

  DOI：——

  日期：——