2-(α-chloro-4′-methylbenzylidene)-1,1,3,3-tetramethylindane | 1448719-94-5

• 分子结构分类: 有机化合物 - 苯类化合物 - 茚满类
• 英文名称: 2-(α-chloro-4′-methylbenzylidene)-1,1,3,3-tetramethylindane
• 英文别名: 2-[Chloro-(4-methylphenyl)methylidene]-1,1,3,3-tetramethylindene；2-[chloro-(4-methylphenyl)methylidene]-1,1,3,3-tetramethylindene
• CAS: 1448719-94-5
• 化学式: C₂₁H₂₃Cl
• 分子量: 310.867
• InChiKey: ZETWWQCBKIKARW-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  6.6
• 重原子数：
  22
• 可旋转键数：
  1
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.33
• 拓扑面积：
  0
• 氢给体数：
  0
• 氢受体数：
  0

反应信息

• 作为反应物：
  描述：

  (trimethylstannyl)lithium 、 2-(α-chloro-4′-methylbenzylidene)-1,1,3,3-tetramethylindane 以 四氢呋喃 为溶剂， 反应 1.08h， 以52%的产率得到2-(4′-methyl-α-trimethylstannylbenzylidene)-1,1,3,3-tetramethylindane
  参考文献：
  名称：

  Pseudomonomolecular, Ionic sp²-Stereoinversion Mechanism of 1-Aryl-1-alkenyllithiums

  摘要：

  The trans/cis stereoinversion of the trigonal carbanion centers C-alpha in a series of monomeric 2-(alpha-aryl-alpha-lithiomethylidene)-1,1,3,3-tetramethylindanes (known to be trisolvated at Li) is rapid on the NMR time scales (400 and 100.6 MHz) in THF solution. The far-reaching redistribution of electric charge in the ground-state molecules caused by lithiation (formal replacement of alpha-H by alpha-Li) is illustrated through NMR shifts, Delta delta. The transition states for stereoinversion are significantly more polar and charge-delocalized than the ground states (Hammett rho = +5.2), pointing to a mechanism that involves heterolysis of the C-Li bond via a solvent-separated ion pair (SSIP). This requires immobilization of only one additional (the fourth) THF molecule at Li+, which accounts for part of the apparent activation entropies of ca. -23 cal mol(-1) K-1 and constitutes a kinetic privilege of THF depending on microsolvation at Li. Thus, the sp(2)-stereoinversion process is "catalyzed" by the solvent THF; its mechanism is monomolecular with respect to the ground-state species because the pseudo-first-order rate constants, measured through NMR line shape analyses, are independent of the concentrations (inclusive of decomposition) of the dissolved species (hence no associations and no dissociation to give free carbanion intermediates). In the deduced pseudomonomolecular mechanism (bimolecular through solvent participation), the angular C-alpha of the SSIP undergoes rehybridization (approximately in-plane inversion) through a close-to-linear transition state; this motion occurs with a concomitant "conducted tour" migration of Li(THF)(4) and is unimpaired by additional ortho-methylations at alpha-aryl. The synthetic route started with preparations of three alpha-chloro congeners through the carbenoid chain reaction, followed by vinylic substitution of alpha-Cl by alpha-SnMe3 (most efficient in THF despite steric congestion). The final Sn/Li interchange reaction afforded the new 1-aryl-1-alkenyllithium samples, initially uncontaminated by free Li+.

  DOI：

  10.1021/om4000852
• 作为产物：
  描述：

  对溴甲苯 以 甲基叔丁基醚 、 正戊烷 为溶剂， 反应 4.0h， 生成 2-(α-chloro-4′-methylbenzylidene)-1,1,3,3-tetramethylindane
  参考文献：
  名称：

  Pseudomonomolecular, Ionic sp²-Stereoinversion Mechanism of 1-Aryl-1-alkenyllithiums

  摘要：

  The trans/cis stereoinversion of the trigonal carbanion centers C-alpha in a series of monomeric 2-(alpha-aryl-alpha-lithiomethylidene)-1,1,3,3-tetramethylindanes (known to be trisolvated at Li) is rapid on the NMR time scales (400 and 100.6 MHz) in THF solution. The far-reaching redistribution of electric charge in the ground-state molecules caused by lithiation (formal replacement of alpha-H by alpha-Li) is illustrated through NMR shifts, Delta delta. The transition states for stereoinversion are significantly more polar and charge-delocalized than the ground states (Hammett rho = +5.2), pointing to a mechanism that involves heterolysis of the C-Li bond via a solvent-separated ion pair (SSIP). This requires immobilization of only one additional (the fourth) THF molecule at Li+, which accounts for part of the apparent activation entropies of ca. -23 cal mol(-1) K-1 and constitutes a kinetic privilege of THF depending on microsolvation at Li. Thus, the sp(2)-stereoinversion process is "catalyzed" by the solvent THF; its mechanism is monomolecular with respect to the ground-state species because the pseudo-first-order rate constants, measured through NMR line shape analyses, are independent of the concentrations (inclusive of decomposition) of the dissolved species (hence no associations and no dissociation to give free carbanion intermediates). In the deduced pseudomonomolecular mechanism (bimolecular through solvent participation), the angular C-alpha of the SSIP undergoes rehybridization (approximately in-plane inversion) through a close-to-linear transition state; this motion occurs with a concomitant "conducted tour" migration of Li(THF)(4) and is unimpaired by additional ortho-methylations at alpha-aryl. The synthetic route started with preparations of three alpha-chloro congeners through the carbenoid chain reaction, followed by vinylic substitution of alpha-Cl by alpha-SnMe3 (most efficient in THF despite steric congestion). The final Sn/Li interchange reaction afforded the new 1-aryl-1-alkenyllithium samples, initially uncontaminated by free Li+.

  DOI：

  10.1021/om4000852

文献信息

• Ring expansion and vinylic nucleophilic substitution competing for (tert-alkyl)2CC(Li)–Cl in carbenoid chain processes
  作者：Rudolf Knorr、Thomas Menke、Karsten-Olaf Hennig、Johannes Freudenreich、Petra Böhrer、Bernhard Schubert

  DOI：10.1016/j.tet.2014.03.004

  日期：2014.4

  (tert-alkyl)2CC(Li)–Cl as transient intermediates. The chains are longer and the overall reactions much slower in tert-butyl methyl ether (t-BuOMe) than in THF as the solvent. In competition with the fast SNV step of these Cl,Li-carbenoids, the Fritsch–Buttenberg–Wiechell (FBW) ring expansion in t-BuOMe (but less so in THF) generates short-lived cyclohexyne species, which are trapped by the accompanying

  乙烯基亲核取代（S Ñ V）未活化的，环状的α的反应，α-dichloroalkenes [（叔烷基）2 ç的CCl 2 ]与芳基锂（RLi的），得到（叔烷基）2 Ç C（Cl）的-R是被认为是类胡萝卜素链反应，涉及不饱和Cl，Li-类胡萝卜素（叔烷基）2 C C（Li）–Cl作为过渡中间体。与作为溶剂的THF相比，叔丁基甲基醚（t -BuOMe）中的链更长，总反应慢得多。与快速的S N竞争这些Cl，Li类胡萝卜素的V阶跃，在t -BuOMe中的Fritsch–Buttenberg–Wiechell（FBW）环膨胀（但在THF中则较少）产生了短寿命的环己炔物种，这些环己炔物种被伴随的RLi物种捕获以产生氯环己烯衍生物[（叔烷基）–（Cl）C C（R）–（叔烷基）]作为FBW链产物。
• Pseudomonomolecular, Ionic sp²-Stereoinversion Mechanism of 1-Aryl-1-alkenyllithiums
  作者：Rudolf Knorr、Thomas Menke、Claudia Behringer、Kathrin Ferchland、Johann Mehlstäubl、Ernst Lattke

  DOI：10.1021/om4000852

  日期：2013.8.12

  The trans/cis stereoinversion of the trigonal carbanion centers C-alpha in a series of monomeric 2-(alpha-aryl-alpha-lithiomethylidene)-1,1,3,3-tetramethylindanes (known to be trisolvated at Li) is rapid on the NMR time scales (400 and 100.6 MHz) in THF solution. The far-reaching redistribution of electric charge in the ground-state molecules caused by lithiation (formal replacement of alpha-H by alpha-Li) is illustrated through NMR shifts, Delta delta. The transition states for stereoinversion are significantly more polar and charge-delocalized than the ground states (Hammett rho = +5.2), pointing to a mechanism that involves heterolysis of the C-Li bond via a solvent-separated ion pair (SSIP). This requires immobilization of only one additional (the fourth) THF molecule at Li+, which accounts for part of the apparent activation entropies of ca. -23 cal mol(-1) K-1 and constitutes a kinetic privilege of THF depending on microsolvation at Li. Thus, the sp(2)-stereoinversion process is "catalyzed" by the solvent THF; its mechanism is monomolecular with respect to the ground-state species because the pseudo-first-order rate constants, measured through NMR line shape analyses, are independent of the concentrations (inclusive of decomposition) of the dissolved species (hence no associations and no dissociation to give free carbanion intermediates). In the deduced pseudomonomolecular mechanism (bimolecular through solvent participation), the angular C-alpha of the SSIP undergoes rehybridization (approximately in-plane inversion) through a close-to-linear transition state; this motion occurs with a concomitant "conducted tour" migration of Li(THF)(4) and is unimpaired by additional ortho-methylations at alpha-aryl. The synthetic route started with preparations of three alpha-chloro congeners through the carbenoid chain reaction, followed by vinylic substitution of alpha-Cl by alpha-SnMe3 (most efficient in THF despite steric congestion). The final Sn/Li interchange reaction afforded the new 1-aryl-1-alkenyllithium samples, initially uncontaminated by free Li+.