4-methoxybenzyl 2,2,2-trifluoroethyl ether | 446867-23-8

• 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: 4-methoxybenzyl 2,2,2-trifluoroethyl ether
• 英文别名: p-methoxybenzyl 2,2,2-trifluoroethyl ether；1-Methoxy-4-(2,2,2-trifluoroethoxymethyl)benzene；1-methoxy-4-(2,2,2-trifluoroethoxymethyl)benzene
• CAS: 446867-23-8
• 化学式: C₁₀H₁₁F₃O₂
• 分子量: 220.191
• InChiKey: ZGWAZYJFAFRLLZ-UHFFFAOYSA-N

物化性质

• 沸点：
  232.1±35.0 °C(Predicted)
• 密度：
  1.186±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  2.7
• 重原子数：
  15
• 可旋转键数：
  4
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.4
• 拓扑面积：
  18.5
• 氢给体数：
  0
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  4-methoxybenzyl 2,2,2-trifluoroethyl ether 在 正丁基锂 作用下， 以 乙醚 、 正己烷 、 二氯甲烷 为溶剂， 反应 120.0h， 生成 4-carbomethoxy-5-endo-[(p-methoxybenzyl)oxy]-6,6-difluoro-3-oxo-2-oxabicyclo[2.2.2]oct-7-ene
  参考文献：
  名称：

  2,2-Disubstituted analogues of the natural hormone 1α,25-dihydroxyvitamin D 3 : chemistry and biology

  摘要：

  Six new 2, 2-disubstituted analogues of the natural hormone calcitriol have been prepared. Chemical novelty includes (1) the first example of an inverse-electron-demand Diels-Alder cycloaddition using a pyrone diene and a difluorinated vinyl ether dienophile, leading to difluorinated analogues 7 and (2) a conceptually streamlined approach to dimethylated 19-nor analogues 8. Analogues 7a and 8a are similar to calcitriol in terms of in vitro antiproliferative activity, but they are different from calcitriol in terms of transcriptional activity: difluorinated analogue 7a is 2-3 times more active transcriptionally than calcitriol, whereas dimethylated analogue 8a is 7.5 times less active transcriptionally. Whereas the in vivo calcemic activity of difluorinated analogue 7a is similar to that of calcitriol, dimethylated analogue 8a is considerably less calcemic than calcitriol. Dimethylated analogue 8a strongly suppresses parathyroid hormone (PTH) secretion. (C) 2002 Elsevier Science Ltd. All rights reserved.

  DOI：

  10.1016/s0968-0896(02)00058-5
• 作为产物：
  描述：

  2,2,2-三氟乙醇 、 1-methoxy-4-((trifluoromethylsulfonyl)methyl)benzene 在 三乙胺 作用下， 生成 4-methoxybenzyl 2,2,2-trifluoroethyl ether
  参考文献：
  名称：

  Nucleofugality of the sulfinate group in carbocation-forming processes

  摘要：

  DOI：

  10.1021/jo00225a017

文献信息

• Lifetimes and UV-visible absorption spectra of benzyl, phenethyl, and cumyl carbocations and corresponding vinyl cations. A laser flash photolysis study
  作者：Frances L Cozens、V M Kanagasabapathy、Robert A McClelland、Steen Steenken

  DOI：10.1139/v99-210

  日期：1999.12.5

  Benzyl (4-MeO, 4-Me, and 4-methoxy-1-naphthylmethyl), phenethyl (4-Me₂N, 4-MeO, 3,4-(MeO)₂, 4-Me, 3-Me, 4-F, 3-MeO, 2,6-Me₂, parent, and 4-methoxy-1-naphthylethyl) and cumyl (4-Me₂N, 4-MeO, 4-Me, parent) cations have been studied by laser flash photolysis (LFP) in 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoroisopropanol (HFIP). In most cases styrene or α-methylstyrene precursors were employed for the phenethyl and cumyl ions, the intermediate being obtained by solvent protonation of the excited state. Benzyl cations were generated by photoheterolysis of trimethylammonium and chloride precursors. While a 4-MeO substituent provides sufficient stabilization to permit observation of cations in TFE, cations with less stabilizing substituents usually require the less nucleophilic HFIP. Even in this solvent, the parent benzyl cation is too short-lived (lifetime <20 ns) to be observed. When generated in HFIP, phenethyl cations can be seen to react with unphotolyzed styrene, giving rise to dimer cations that are observed to grow in as the initial phenethyl cation decays. The dimer cations, in common with the oligomer cations seen in cationic styrene polymerization, have a λ_max 15-20 nm higher than the monomer and react with both solvent and styrene several orders of magnitude more slowly. This stabilization relative to the phenethyl may reflect an interaction with the aryl group present at the gamma-carbon. Cations 4-MeOC₆H₄C⁺(R)-CH₃ (R = Me, Et, i-Pr, t-Bu, cyclopropyl, C₆H₅, 4-MeOC₆H₄) were generated in TFE via the photoprotonation route. The alkyl series shows that steric effects are important in the decay reaction. The cation with R = cyclopropyl is a factor of 1.5 less reactive than the cation where R = phenyl. Several vinyl cations have also been generated by photoprotonation of phenylacetylenes. ArC⁺=CH₂ has a reactivity very similar to that of its analog ArC⁺H-CH₃, the vinyl cation being slightly (factors of 2-5) shorter-lived. For the various series of cations, including vinyl, substituents in the aryl ring have a consistent effect on the λ_max, a shift to higher wavelength relative to hydrogen of 15 nm for 4-Me, 30 nm for 4-MeO, and 50 nm for 4-Me₂N.Key words: photogenerated carbocations, carbocation lifetime, styrene, photoprotonation.

  苯甲基（4-MeO，4-Me和4-甲氧基-1-萘基甲基）、苯乙基（4-Me2N，4-MeO，3,4-(MeO)2，4-Me，3-Me，4-F，3-MeO，2,6-Me2，母体和4-甲氧基-1-萘基乙基）和叔丁基（4-Me2N，4-MeO，4-Me，母体）阳离子在2,2,2-三氟乙醇（TFE）和1,1,1,3,3,3-六氟异丙醇（HFIP）中通过激光闪光光解（LFP）进行了研究。在大多数情况下，苯乙烯或α-甲基苯乙烯前体被用于苯乙基和叔丁基离子，中间体通过溶剂质子化激发态而获得。苯甲基阳离子是通过三甲基铵和氯化物前体的光异裂生成的。虽然4-MeO取代基提供了足够的稳定性以在TFE中观察到阳离子，但具有较少稳定取代基的阳离子通常需要较不亲核的HFIP。即使在这种溶剂中，母体苯甲基阳离子也太短寿命（寿命<20 ns）而无法观察到。在HFIP中生成的苯乙基阳离子可以看到与未经光解的苯乙烯反应，导致观察到的二聚体阳离子在初始苯乙基阳离子衰减时增长。与阳离子苯乙烯聚合中观察到的寡聚体阳离子一样，二聚体阳离子的λmax比单体高15-20 nm，并且与溶剂和苯乙烯反应速度慢几个数量级。相对于苯乙基的这种稳定性可能反映了与伽马碳上存在的芳基的相互作用。在TFE中通过光质子化途径生成了4-MeOC6H4C+(R)-CH3（R = Me，Et，i-Pr，t-Bu，环丙基，C6H5，4-MeOC6H4）阳离子。烷基系列表明立体效应在衰减反应中很重要。当R = 环丙基时，其反应性比R = 苯基的阳离子少1.5倍。还通过对苯乙炔的光质子化生成了几种乙烯阳离子。ArC+=CH2的反应性与其类似物ArC+H-CH3非常相似，乙烯阳离子寿命略短（2-5倍因子）。对于包括乙烯在内的各系列阳离子，芳香环中的取代基对λmax有一致的影响，相对于氢的15 nm的4-Me，30 nm的4-MeO和50 nm的4-Me2N的波长偏移。关键词：光产生的碳正离子，碳正离子寿命，苯乙烯，光质子化。
• Solvolysis of substituted benzyl azoxyarenesulfonates:The IUPAC name for benzyl azoxyarenesulfonate is N-benzyl-N′-arylsulfonyloxydiazene N-oxide. characterisation of the transition state and the selectivity of benzylic intermediates in 50% aqueous 2,2,2-trifluoroethanolElectronic supplementary information (ESI) available: synthesis and analytical data of azoxyarenesulfonates. See http://www.rsc.org/suppdata/p2/b1/b106887n
  作者：Isobel M. Gordon、Howard Maskill

  DOI：10.1039/b106887n

  日期：2001.11.1

  Thirteen substituted benzyl azoxyarenesulfonates have been prepared and rate constants for solvolysis of twelve have been measured in 50% (v/v) aqueous 2,2,2-trifluoroethanol over a range of temperatures from which activation parameters and rate constants at 25 °C have been determined. A six-point Hammett correlation for substituents in the benzylic electrofuge, with azoxytoluene-p-sulfonate as the common nucleofuge, gives ρ(σ+) = −3.27. With 4-methylbenzyl as a common electrofuge, four substituents in the azoxybenzenesulfonate nucleofuge give ρ(σ) = 1.07. Comparison with model reactions indicates a synchronous concerted rate-limiting fragmentation for these substrates. With the less reactive 3-chlorobenzyl as electrofuge, ρ for substituents in the nucleofuge is only ca. 0.7 which indicates a lower degree of charge development in the arenesulfonate in the transition state for these reactions. Product analyses have been carried out for compounds of high, intermediate, and low reactivity. These indicate a reactivity–selectivity relationship for capture of the substituted benzylic electrophiles by water and 2,2,2-trifluoroethanol. Substituted benzaldehydes are formed from the less reactive substrates, indicating trapping of the first-formed benzylic carbenium ion by nitrous oxide and subsequent elimination of nitrogen and a proton; but yields are low and decrease as the substituted benzyl cation becomes increasingly stable.

  我们制备了 13 种取代的苄基偶氮苯磺酸盐，并测量了其中 12 种在 50% (v/v) 2,2,2- 三氟乙醇水溶液中一定温度范围内的溶解速率常数，据此确定了 25 °C 时的活化参数和速率常数。以偶氮甲苯对磺酸盐为普通核苷酸，苄基电泳中取代基的六点哈米特相关性得出 ρ(σ+) =-3.27。以 4-甲基苄基作为普通电解质，偶氮苯磺酸酯核苷酸中的四个取代基给出了 ρ(σ) = 1.07。与模型反应的比较表明，这些底物发生了同步的协同限速破碎。用反应性较低的 3-氯苄基作为电助剂时，核助剂中取代基的 ρ 仅为 0.7 左右，这表明在这些反应的过渡态中，异壬磺酸盐的电荷发展程度较低。针对高、中、低反应活性的化合物进行了产物分析。这些分析表明，水和 2,2,2-三氟乙醇捕获取代的苄基亲电体存在反应活性-选择性关系。从反应性较低的底物中生成了取代的苯甲醛，这表明氧化亚氮捕获了第一种生成的苄基羰离子，随后消除了氮和一个质子；但是产量很低，而且随着取代的苄基阳离子变得越来越稳定，产量也在降低。
• Distinguishing between solvation effects and mechanistic changes. Effects due to differences in solvation of aromatic rings and alkyl groups
  作者：T. William Bentley、In Sun Koo、Simon J. Norman

  DOI：10.1021/jo00004a048

  日期：1991.2

  Solvolytic rate constants at 25-degrees-C are reported for p-methoxybenzyl chloride (1) in aqueous binary mixtures with acetone, acetonitrile, dioxane, dimethyl sulfoxide, ethanol, methanol, and 2,2,2-trifluoroethanol and for benzoyl chloride and p-methoxybenzoyl chloride (2) in aqueous acetonitrile and aqueous dioxane. Product selectivities are reported for solvolyses of 1 in aqueous ethanol and methanol. Logarithms of rate constants for solvolyses of 2 correlate linearly with solvolyses of 1 (unit slope and only a small ''dispersion''-the tendency for the various binary mixtures to show separate correlations), showing that the solvation requirements of S(N)1 reactions of aromatic carboxylic acid chlorides are very similar to those of benzylic chlorides. Similar good correlations are reported vs solvolyses of alpha-phenylethyl chloride and vs Z values. For S(N)1 reactions of chlorides in binary mixtures having similar electrophilicities, the phenomenon of dispersion in Grunwald-Winstein plots (vs Y) and the poor correlation vs Y(Cl) (reported previously) appears to be due to the differences in solvation between aromatic rings and alkyl groups; this difference is largest for binary aqueous mixtures with methanol > ethanol > aprotic solvents. The complex rate-rate profile for similar solvolytic reactions of benzoyl chloride is dissected quantitatively into contributions from two competing reaction channels, one of which shows only a small ''dispersion'' in a correlation with solvolyses of 2; these results are consistent with a mainly dissociative reaction channel for solvolyses of benzoyl chloride in highly aqueous media.
• Mechanisms of Benzyl Group Transfer in the Decay of (E)-Arylmethanediazoates and Aryldiazomethanes in Aqueous Solutions
  作者：Jari I. Finneman、James C. Fishbein

  DOI：10.1021/ja00120a004

  日期：1995.4

  Rate constants are reported for the buffer-independent decay of ten (E)-arylmethanediazontes in aqueous media at 25 degrees C, ionic strength 1 M (NaClO4), 4% 2-propanol, in the region of pH 4-12. The rate constants are proportional to hydrogen ion concentration at high pH and become pH independent in the low-pH region. Varying concentrations of oxyanion, amine, and hydrazine buffers over the range 0.05-0.2 M increased the pseudo-first-order rate constant for decay of the diazoates by less than 10%. The azide-water selectivities, k(2)/k(5), for partitioning of the benzyl groups in the decay of (E)-(3,5-bis(trifluoromethyl)phenyl)methanediazonate and the (3,5-bis(trifluoromethyl)phenyl)diazomethane are determined to be 0.20 and 0.21 M(-1), respectively, in phosphate buffered water and 0.27 and 0.26 M(-1), respectively, in 20/80 DMSO-water. It is concluded that these two reactants decompose, in these media, via a common free diazonium ion intermediate that is formed in the case of the diazoate upon unassisted N-O bond cleavage of the diazoic acid. A common rate-limiting step is indicated for all the diazoates by the correlation line for the plot of log k(1), the pH independent rate constant, against sigma that has a slope rho = -1.23. Product ratios for trapping of benzyl groups derived from other pairs of arylmethanediazoates and aryldiazomethanes with less electron withdrawing groups are different outside experimental error, indicating the importance of different nitrogen-separated ion pairs in these reactions. The (E)-(p-methoxy)phenyl)methane-(16)-diazoat decomposes in O-16/O-18 water to give alcohol that has an ''excess'' abundance of O-16 compared to solvent, Decomposition of the same compound in 50/50 trifluoroethanol-water with varying concentrations of azide indicates that azide ion appears to trap a limiting amount, similar to 80%, of the p-methoxybenzyl group. Quantitative analysis of the data indicates that 16% of the p-methoxybenzyl cation is trapped by solvent at the nitrogen-separated ion pair stage, in the absence of azide ion, There is a 9-fold enhancement of selectivity for trifluoroethanol at the ion pair stage that is ascribed to a proton switch initiated by the leaving hydroxide ion in the ion pair. The values of k(2)/k(5) similar to 0.2 M(-1) and k(T)/k(H) similar to 0.5-0.6 for the trifluoroethanol-water selectivity and k(ET)/k(T) similar to 1 for the ethanol-trifluoroethanol selectivity are independent of substituent in the decay of arylmethanediazoates (X = H and EWG) in water, water-trifluoroethanol (50/50), and water-trifluoroethanol-ethanol (50/40/10), respectively. It is concluded from this that the product-determining steps do not involve chemical bonding but rather rotational/translational reorientation of the nucleophiles in the first solvation sphere of the carbocation intermediates. It is concluded that the values of k(H)/k(T) = 0.5-0.6 indicate preferential solvation of the cation precursor by trifluoroethanol. It is shown that a preferential interaction for trifluoroethanol of <1 kcal/mol is required to generate the observed selectivities.
• Electrophilic Alkylations in Neutral Aqueous or Alcoholic Solutions
  作者：Matthias Hofmann、Nathalie Hampel、Tanja Kanzian、Herbert Mayr

  DOI：10.1002/anie.200460812

  日期：2004.10.11