ethyl 6-methyl-3-(4-nitrophenyl)-2H-1,4-oxazine-5-carboxylate | 1431934-83-6

• 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: ethyl 6-methyl-3-(4-nitrophenyl)-2H-1,4-oxazine-5-carboxylate
• CAS: 1431934-83-6
• 化学式: C₁₄H₁₄N₂O₅
• 分子量: 290.276
• InChiKey: TYLIWFFMPPCLNQ-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.3
• 重原子数：
  21
• 可旋转键数：
  4
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.29
• 拓扑面积：
  93.7
• 氢给体数：
  0
• 氢受体数：
  6

反应信息

• 作为产物：
  描述：

  重氮基乙酰乙酸乙酯 、 3-(4-硝基苯基)-2H-吖丙因 在 dirhodium tetraacetate 作用下， 以 1,2-二氯乙烷 为溶剂， 以79%的产率得到ethyl 6-methyl-3-(4-nitrophenyl)-2H-1,4-oxazine-5-carboxylate
  参考文献：
  名称：

  Rh(II)-carbenoid mediated 2H-azirine ring-expansion as a convenient route to non-fused photo- and thermochromic 2H-1,4-oxazines

  摘要：

  The Rh2(OAc)(4)-catalyzed domino reaction of 2H-azirines with 2-acyl-2-diazoacetates provides a unique synthetic approach to non-fused 2H-1,4-oxazines. The reaction proceeds via sequential formation of a rhodium carbenoid, an azirinium ylide, and a 1-acyl-1-(alkoxycarbonyl)-2-azabuta-1,3-diene to give, after 1,6-pi-electrocyclization, a 2H-1,4-oxazine derivative in good yield. The observed stereoselectivity of 2-azadiene formation is consistent with DFT calculations of the azirinium ylide-2-azadiene isomerization, providing evidence for the ylide mechanism of the reaction. The substitution pattern and configuration of the carbon carbon double bond in 2-azadienes has a dramatic influence on their cyclization to oxazines: the CO2R group on C-4 stabilizes an open-chain form and, as the result of this, a new class of stable 2-azadienes, 1-acyl-2-azadiene-1,4-dicarboxylates, could be isolated. The 1,4-oxazines obtained by this method are the first representatives of monocyclic 2H-1,4-oxazine derivatives, which exhibit photo- and thermochromic activity. (C) 2013 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.tet.2013.03.106

文献信息

• Azirinium ylides from α-diazoketones and 2<i>H</i>-azirines on the route to 2<i>H</i>-1,4-oxazines: three-membered ring opening vs 1,5-cyclization
  作者：Nikolai V Rostovskii、Mikhail S Novikov、Alexander F Khlebnikov、Galina L Starova、Margarita S Avdontseva

  DOI：10.3762/bjoc.11.35

  日期：——

  Strained azirinium ylides derived from 2H-azirines and alpha-diazoketones under Rh(II)-catalysis can undergo either irreversible ring opening across the N-C2 bond to 2-azabuta-1,3-dienes that further cyclize to 2H-1,4-oxazines or reversibly undergo a 1,5-cyclization to dihydroazireno[2,1-b]oxazoles. Dihydroazireno[2,1-b]oxazoles derived from 3-aryl-2H-azirines and 3-diazoacetylacetone or ethyl diazoacetoacetate

  在Rh（II）催化下，衍生自2H-叠氮基和α-二氮酮的叠氮化萘可经历不可逆的开环，穿过N-C2键与2-azabuta-1,3-dienes结合，进一步环化成2H-1,4 -恶嗪或可逆地经历1,5-环化反应生成二氢叠氮基[2,1-b]恶唑。由3-芳基-2H-叠氮基和3-重氮乙酰丙酮或重氮乙酰乙酸乙酯合成的二氢叠氮基[2,1-b]恶唑能够在Rh（II）催化下环加到由3-重氮乙酰丙酮生成的乙酰基（甲基）乙烯酮中，得到4， 6-二氧杂-1-氮杂双环[3.2.1]辛-2-烯和/或5,7-二氧杂-1-杂双环[4.3.1]十-3,8-二烯-2-酮衍生物。根据DFT计算（B3LYP / 6-31 + G（d，p）），环加成反应可能涉及二氢叠氮壬酸酯的亲核攻击的两种模式[2，1-b]恶唑中间体在乙酰基（甲基）乙烯酮上，然后将氮丙啶开环成对映异构体恶唑鎓甜菜碱并环化。由2，3-二-和2，2，3-三芳基取代的叠