5-methyl-1H-1,3-benzazaphosphole | 1395459-82-1

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吲哚及其衍生物
• 英文名称: 5-methyl-1H-1,3-benzazaphosphole
• CAS: 1395459-82-1
• 化学式: C₈H₈NP
• 分子量: 149.132
• InChiKey: QCIBFJREKBWHJY-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.06
• 重原子数：
  10.0
• 可旋转键数：
  0.0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.12
• 拓扑面积：
  15.79
• 氢给体数：
  1.0
• 氢受体数：
  0.0

反应信息

• 作为反应物：
  描述：

  三甲基氯硅烷 、 5-methyl-1H-1,3-benzazaphosphole 、 叔丁基锂 以 甲苯 为溶剂， 以71%的产率得到3-tert-butyl-5-methyl-1,2-bis(trimethylsilyl)-2,3-dihydro-1H-1,3-benzazaphosphole
  参考文献：
  名称：

  Solvent-controlled lithiation of PC–N-heterocycles: Synthesis of mono- and bis(trimethylsilyl)-tert-butyl-dihydrobenzazaphospholes – A new type of highly bulky and basic phosphine ligands

  摘要：

  The influence of solvents on the lithiation of N-methyl-1,3-benzazaphospholes is reported; these are accessible via catalytic phosphonylation of 2-bromoanilines, subsequent reduction to 2-phosphinoanilines and acid-catalysed disproportionative ring closure with excess paraformaldehyde. Reactions with tBuLi in polar solvents (THF, Et2O), particularly in the presence of tBuOK, lead to 2-lithiobenzazaphospholes (CH-lithiation) whereas hydrocarbons favour "normal" (hexane) or "inverse" (toluene) addition at the P=C bond. Reactive Li-species were trapped by ClSiMe3, present during the lithiation in hydrocarbons, and give rise to 2- and 3-trimethylsilyl-dihydro-1,3-benzazaphospholes, respectively. In hexane, via preferred lithiation of the primary adduct, the 2,2'-bis(trimethylsilyl)-dihydro-1,3-benzazaphosphole is the main product. 5-Methyl-1,3-benzazaphosphole, with NH function, reacts in toluene in the "normal" mode to 3-tert-butyl-1,2-bis(trimethylsilyl)-5-methyl-dihydrobenzazaphosphole. The sterically demanding tert-butyl and trimethylsilyl groups are arranged in anti-position as shown by crystal structure analyses, the second 2-SiMe3 group in gauche position. The P-tert-butyl-2,2'-bis(trimethylsilyl)-dihydrobenzazaphospholes represent a new type of sterically congested dialkylaryl phosphine ligands with increased basicity by the +I-effect of the silyl groups and +M-effect of the basic nitrogen in o-position. (C) 2014 Elsevier B.V. All rights reserved.

  DOI：

  10.1016/j.jorganchem.2014.04.014
• 作为产物：
  描述：

  N-(2-bromo-4-methylphenyl)formamide 在 lithium aluminium tetrahydride 、 palladium dichloride 作用下， 以 乙醚 为溶剂， 反应 96.59h， 生成 5-methyl-1H-1,3-benzazaphosphole
  参考文献：
  名称：

  N-Formyl-2-bromoanilides 合成 2-未取代的 1H-1,3-Benzazaphospholes

  摘要：

  在预先形成的 Pd(0)(亚磷酸三乙酯)n 催化剂存在下，2-溴-甲酰苯胺 1 与亚磷酸三乙酯的膦酰化以良好的产率提供了 2-膦酰-甲酰苯胺 2。用过量的 LiAlH4 还原主要提供 N-甲基-2-膦基苯胺 3 和少量 1,2-未取代的苯并氮杂磷 4。N-甲基-1,3-苯扎磷 5 是通过 3 与二甲基甲酰胺二甲基缩醛 (DMFA) 的环缩合反应合成的。避免 4 的色谱分离，更方便的 5 路线是将 1 还原为 2-溴-N-甲基苯胺 6，然后进行膦酰化为 7，LiAlH4 还原，然后用 DMFA 环化。苯扎磷光体在 σ2P 处的配位特性由 (5b)W(CO)5 的晶体结构分析获得的结构数据表征。

  DOI：

  10.1002/hc.21111

文献信息

• σ2-P Ligands: convenient syntheses of N-methyl-1,3-benzazaphospholes
  作者：Mohammed Ghalib、Basit Niaz、Peter G. Jones、Joachim W. Heinicke

  DOI：10.1016/j.tetlet.2012.07.037

  日期：2012.9

  A convenient three-step route to 1,5-dimethyl-1,3-benzazaphosphole via Cu- or Pd-catalyzed phosphonylation of 2-iodo-4-methylaniline, reduction to 2-phosphino-4-methylaniline, and disproportionative cyclization with excess formaldehyde is reported. N-Methylbenzazaphospholes can be functionalized in the 2-position via alpha-CH-lithiation with tBuLi and are pi-acidic sigma P-2-ligands. (C) 2012 Elsevier Ltd. All rights reserved.
• Coplanar Tetracyclic π‐Excess σ ² P Ligands
  作者：Basit Niaz、Fatima Iftikhar、Markus K. Kindermann、Peter G. Jones、Joachim Heinicke

  DOI：10.1002/ejic.201300342

  日期：2013.8.12

  AbstractThe acid‐catalyzed reactions of 5‐methyl‐2‐phosphanylaniline (1) with dialdehydes were studied. Whereas the reaction with glyoxal provides a mixture of two 1H‐1,3‐benzazaphospholes, 2 and 3, by concomitant reduction of a CHO group and C–C bond cleavage, respectively, the reaction with o‐phthalic dicarbaldehyde provided in excellent yield the tetracyclic planar benzazaphosphole 4, which was characterized by crystal structure analysis. The active hydrogen atoms, delivered by aromatization of a dihydrobenzazaphosphole intermediate, forms an N–CH2 bridge by reductive N‐alkylation. Pyridine‐2,6‐dicarbaldehyde reacts analogously but not chemoselectively and, thus, gives two isomers 5 and 6. Condensation with pyridine‐2,6‐dicarbaldehyde afforded the bis(benzazaphosphole)pyridine pincer ligand 7, but along with 2‐(benzazaphospholyl)‐6‐tolylpyridine (8) by partial P–C bond cleavage. The high upfield 31P NMR chemical shift of 4 compared to those of normal benzazaphospholes indicates it to be a particularly π‐rich σ2P ligand.