2-(4-methoxyphenyl)-4-methyloxazol-5-yl methyl carbonate | 217446-01-0

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 唑类
• 英文名称: 2-(4-methoxyphenyl)-4-methyloxazol-5-yl methyl carbonate
• 英文别名: [2-(4-Methoxyphenyl)-4-methyl-1,3-oxazol-5-yl] methyl carbonate
• CAS: 217446-01-0
• 化学式: C₁₃H₁₃NO₅
• 分子量: 263.25
• InChiKey: QXHHBLHCKJSEEM-UHFFFAOYSA-N

物化性质

• 熔点：
  57-58 °C
• 沸点：
  406.2±55.0 °C(Predicted)
• 密度：
  1.224±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  2.9
• 重原子数：
  19
• 可旋转键数：
  5
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.23
• 拓扑面积：
  70.8
• 氢给体数：
  0
• 氢受体数：
  6

反应信息

• 作为反应物：
  描述：

  2-(4-methoxyphenyl)-4-methyloxazol-5-yl methyl carbonate 在 双(三甲基硅烷基)氨基钾 作用下， 以 四氢呋喃 、 甲苯 为溶剂， 反应 0.08h， 以84%的产率得到4-methyl-5-oxo-2-(4-methoxyphenyl)-4,5-dihydrooxazole-4-carboxylic acid methyl ester
  参考文献：
  名称：

  Probing the Efficiency of N-Heterocyclic Carbene Promoted O- to C-Carboxyl Transfer of Oxazolyl Carbonates

  摘要：

  Screening of a range of azolium salts, bases and solvents for reactivity indicates that triazolinylidenes, generated in situ with KHMDS in THF, promote the Steglich rearrangement of oxazolyl carbonates with high catalytic efficiency (typical reaction time 5 min at < 1.5 mol % NHC). This protocol shows wide substrate applicability, even allowing the efficient generation of vicinal quaternary centers. An improved experimental procedure is also described that allows a simplified one-pot reaction protocol to be employed with similarly high catalytic efficiency.

  DOI：

  10.1021/jo702720a
• 作为产物：
  描述：

  2-(4-methoxyphenyl)-4-methyl-5-oxo-4,5-dihydrooxazole 、 氯甲酸甲酯 在 三乙胺 作用下， 以 四氢呋喃 为溶剂， 以87%的产率得到2-(4-methoxyphenyl)-4-methyloxazol-5-yl methyl carbonate
  参考文献：
  名称：

  Probing the Efficiency of N-Heterocyclic Carbene Promoted O- to C-Carboxyl Transfer of Oxazolyl Carbonates

  摘要：

  Screening of a range of azolium salts, bases and solvents for reactivity indicates that triazolinylidenes, generated in situ with KHMDS in THF, promote the Steglich rearrangement of oxazolyl carbonates with high catalytic efficiency (typical reaction time 5 min at < 1.5 mol % NHC). This protocol shows wide substrate applicability, even allowing the efficient generation of vicinal quaternary centers. An improved experimental procedure is also described that allows a simplified one-pot reaction protocol to be employed with similarly high catalytic efficiency.

  DOI：

  10.1021/jo702720a

文献信息

• Enantioselective TADMAP-Catalyzed Carboxyl Migration Reactions for the Synthesis of Stereogenic Quaternary Carbon
  作者：Scott A. Shaw、Pedro Aleman、Justin Christy、Jeff W. Kampf、Porino Va、Edwin Vedejs

  DOI：10.1021/ja056150x

  日期：2006.1.1

  efficient and are used to prepare chiral lactams (23) and lactones (30) containing a quaternary asymmetric carbon. TADMAP-catalyzed carboxyl migrations in the indole series are relatively slow and proceed with inconsistent enantioselectivity. Modeling studies (B3LYP/6-31G*) have been used in qualitative correlations of catalyst conformation, reactivity, and enantioselectivity.

  手性亲核催化剂 TADMAP [1, 3-(2,2,2-三苯基-1-乙酰氧基乙基)-4-(二甲氨基)吡啶]已由 3-锂硫-4-(二甲氨基)吡啶 (5) 和三苯乙醛 (3)，然后进行酰化和拆分。TADMAP 催化恶唑基、呋喃基和苯并呋喃基烯醇碳酸酯的羧基迁移，具有良好到极好的对映选择水平。恶唑反应特别有效，用于制备含有季不对称碳的手性内酰胺 (23) 和内酯 (30)。吲哚系列中 TADMAP 催化的羧基迁移相对较慢，并且具有不一致的对映选择性。建模研究 (B3LYP/6-31G*) 已用于定性关联催化剂构象、反应性和对映选择性。
• Modulating NHC catalysis with fluorine
  作者：Yannick P Rey、Ryan Gilmour

  DOI：10.3762/bjoc.9.316

  日期：——

  Fluorination often confers a range of advantages in modulating the conformation and reactivity of small molecule organocatalysts. By strategically introducing fluorine substituents, as part of a β-fluoroamine motif, in a triazolium pre-catalyst, it was possible to modulate the behaviour of the corresponding N-heterocyclic carbene (NHC) with minimal steric alterations to the catalyst core. In this study, the effect of hydrogen to fluorine substitution was evaluated as part of a molecular editing study. X-ray crystallographic analyses of a number of derivatives are presented and the conformations are discussed. Upon deprotonation, the fluorinated triazolium salts generate catalytically active N-heterocyclic carbenes, which can then participate in the enantioselective Steglich rearrangement of oxazolyl carbonates to C-carboxyazlactones (e.r. up to 87.0:13.0).

  氟化通常在调节小分子有机催化剂的构象和反应性方面带来一系列优势。通过在三唑前驱催化剂中战略性地引入氟取代基，作为β-氟胺基团的一部分，可以调节相应的N-杂环卡宾（NHC）的行为，同时最小程度地改变催化剂核心的立体构型。在这项研究中，氢到氟的取代效应被作为分子编辑研究的一部分进行评估。对多个衍生物进行了X射线晶体学分析，并讨论了构象。去质子化后，氟化三唑盐会产生具有催化活性的N-杂环卡宾，这些卡宾随后可以参与对氧唑基碳酸酯的对映选择性Steglich重排反应，生成C-羧基氮内酯（对映选择性达到87.0:13.0）。
• Organic base effects in NHC promoted O- to C-carboxyl transfer; chemoselectivity profiles, mechanistic studies and domino catalysis
  作者：Craig D. Campbell、Christopher J. Collett、Jennifer E. Thomson、Alexandra M. Z. Slawin、Andrew D. Smith

  DOI：10.1039/c1ob05160a

  日期：——

  The O- to C-carboxyl transfer of oxazolyl carbonates promoted by triazolinylidenes, generated in situ with NEt3, shows a markedly different rate and chemoselectivity profile to the same reaction promoted by triazolinylidenes generated using KHMDS. The mechanism of these pathways has been probed through extensive crossover studies to understand this process. The use of NEt3 as a base allows domino multi-step

  由NEt 3原位产生的由三唑啉亚基促进的碳酸恶唑基碳酸酯的O - C羧基转移与由KHMDS生成的三唑啉亚基促进的相同反应显示出明显不同的速率和化学选择性。通过广泛的交叉研究探索了这些途径的机制，以了解这一过程。尽管手性NHC在这些多米诺反应过程中仅产生适度水平的不对称诱导（<15％ee），但使用NEt 3作为碱基可以开发出多米诺骨牌多步反应序列。
• Catalytic enantioselective Steglich rearrangements using chiral N-heterocyclic carbenes
  作者：Craig D. Campbell、Carmen Concellón、Andrew D. Smith

  DOI：10.1016/j.tetasy.2011.04.001

  日期：2011.4

  The evaluation of a range of enantiomerically pure NHCs, prepared in situ from imidazolinium or triazolium salt precatalysts, to promote the catalytic enantioselective Steglich rearrangement of oxazolyl carbonates to their C-carboxyazlactones, is reported. Modest levels of enantioselectivity (up to 66% ee) are observed using oxazolidinone derived NHCs. (C) 2011 Elsevier Ltd. All rights reserved.
• Efficient N-Heterocyclic Carbene-Catalyzed <i>O</i>- to C-Acyl Transfer
  作者：Jennifer E. Thomson、Kathryn Rix、Andrew D. Smith

  DOI：10.1021/ol061380h

  日期：2006.8.1

  An N-heterocyclic carbene promotes the rearrangement of alpha-amino acid derived O-acyl carbonates to their corresponding C-acylated isomers, generating a C-C bond and a quaternary stereocenter with high efficiency, under mild reaction conditions and with low catalyst loadings.