W(CEt)[OCMe(CF3)2]3(1,2-dimethoxyethane) | 91202-91-4

• 分子结构分类: 有机化合物 - 乙炔化物
• 英文名称: W(CEt)[OCMe(CF3)2]3(1,2-dimethoxyethane)
• 英文别名: (EtC)W(OC(CF3)2Me)3(1,2-dimethoxyethane)
• CAS: 91202-91-4
• 化学式: C₁₉H₂₄F₁₈O₅W
• 分子量: 858.218
• InChiKey: FRBPJZGXJQREKQ-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  None
• 重原子数：
  None
• 可旋转键数：
  None
• 环数：
  None
• sp3杂化的碳原子比例：
  None
• 拓扑面积：
  None
• 氢给体数：
  None
• 氢受体数：
  None

反应信息

• 作为反应物：
  描述：

  W(CEt)[OCMe(CF3)2]3(1,2-dimethoxyethane) 、 1-(1-丁炔-1-基)-4-甲氧基苯 以 not given 为溶剂， 生成 (4-MeO-C6H4C)W(OC(CF3)2Me)3(DME)
  参考文献：
  名称：

  Synthetic, Mechanistic, and Computational Investigations of Nitrile-Alkyne Cross-Metathesis

  摘要：

  The terminal nitride complexes NW(OC(CF3)(2)Me)(3)(DME) (1-DME), [Li(DME)(2)][NW(OC(CF3)(2)Me)(4)] (2), and [NW(OCMe2CF3)(3)](3) (3) were prepared in good yield by salt elimination from [NWCl3](4). X-ray structures revealed that 1-DME and 2 are monomeric in the solid state. All three complexes catalyze the cross-metathesis of 3-hexyne with assorted nitriles to form propionitrile and the corresponding alkyne. Propylidyne and substituted benzylidyne complexes RCW(OC(CF3)(2)Me)(3) were isolated in good yield upon reaction of 1-DME with 3-hexyne or 1-aryl-1-butyne. The corresponding reactions failed for 3. Instead, EtCW(OC(CF3)Me-2)(3) (6) was prepared via the reaction of W-2(OC(CF3)Me-2)(6) with 3-hexyne at 95 degrees C. Benzylidyne complexes of the form ArCW(OC(CF3)Me-2)(3) (Ar = aryl) then were prepared by treatment of 6 with the appropriate symmetrical alkyne ArCCAr. Three coupled cycles for the interconversion of 1-DME with the corresponding propylidyne and benzylidyne complexes via [2 + 2] cycloaddition-cycloreversion were examined for reversibility. Stoichiometric reactions revealed that both nitrile-alkyne cross-metathesis (NACM) cycles as well as the alkyne cross-metathesis (ACM) cycle operated reversibly in this system. With catalyst 3, depending on the aryl group used, at least one step in one of the NACM cycles was irreversible. In general, catalyst 1-DME afforded more rapid reaction than did 3 under comparable conditions. However, 3 displayed a slightly improved tolerance of polar functional groups than did 1-DME. For both 11-DME and 3, ACM is more rapid than NACM under typical conditions. Alkyne polymerization (AP) is a competing reaction with both 1-DME and 3. It can be suppressed but not entirely eliminated via manipulation of the catalyst concentration. As AP selectively removes 3-hexyne from the system, tandem NACM-ACM-AP can be used to prepare symmetrically substituted alkynes with good selectivity, including an arylene-ethynylene macrocycle. Alternatively, unsymmetrical alkynes of the form EtCCR (R variable) can be prepared with good selectivity via the reaction of RCN with excess 3-hexyne under conditions that suppress AP. DFT calculations support a [2 + 2) cycloaddition-cycloreversion mechanism analogous to that of alkyne metathesis. The barrier to azametalacyciobutadiene ring formation/breakup is greater than that for the corresponding metalacyclobutadiene. Two distinct high-energy azametalacyclobutadiene intermediates were found. These adopted a distorted square pyramidal geometry with significant bond localization.

  DOI：

  10.1021/ja800020w
• 作为产物：
  描述：

  3-己炔 、 NW(OC(CF3)2Me)3(DME) 以 甲苯 为溶剂， 以52%的产率得到W(CEt)[OCMe(CF3)2]3(1,2-dimethoxyethane)
  参考文献：
  名称：

  Synthetic, Mechanistic, and Computational Investigations of Nitrile-Alkyne Cross-Metathesis

  摘要：

  The terminal nitride complexes NW(OC(CF3)(2)Me)(3)(DME) (1-DME), [Li(DME)(2)][NW(OC(CF3)(2)Me)(4)] (2), and [NW(OCMe2CF3)(3)](3) (3) were prepared in good yield by salt elimination from [NWCl3](4). X-ray structures revealed that 1-DME and 2 are monomeric in the solid state. All three complexes catalyze the cross-metathesis of 3-hexyne with assorted nitriles to form propionitrile and the corresponding alkyne. Propylidyne and substituted benzylidyne complexes RCW(OC(CF3)(2)Me)(3) were isolated in good yield upon reaction of 1-DME with 3-hexyne or 1-aryl-1-butyne. The corresponding reactions failed for 3. Instead, EtCW(OC(CF3)Me-2)(3) (6) was prepared via the reaction of W-2(OC(CF3)Me-2)(6) with 3-hexyne at 95 degrees C. Benzylidyne complexes of the form ArCW(OC(CF3)Me-2)(3) (Ar = aryl) then were prepared by treatment of 6 with the appropriate symmetrical alkyne ArCCAr. Three coupled cycles for the interconversion of 1-DME with the corresponding propylidyne and benzylidyne complexes via [2 + 2] cycloaddition-cycloreversion were examined for reversibility. Stoichiometric reactions revealed that both nitrile-alkyne cross-metathesis (NACM) cycles as well as the alkyne cross-metathesis (ACM) cycle operated reversibly in this system. With catalyst 3, depending on the aryl group used, at least one step in one of the NACM cycles was irreversible. In general, catalyst 1-DME afforded more rapid reaction than did 3 under comparable conditions. However, 3 displayed a slightly improved tolerance of polar functional groups than did 1-DME. For both 11-DME and 3, ACM is more rapid than NACM under typical conditions. Alkyne polymerization (AP) is a competing reaction with both 1-DME and 3. It can be suppressed but not entirely eliminated via manipulation of the catalyst concentration. As AP selectively removes 3-hexyne from the system, tandem NACM-ACM-AP can be used to prepare symmetrically substituted alkynes with good selectivity, including an arylene-ethynylene macrocycle. Alternatively, unsymmetrical alkynes of the form EtCCR (R variable) can be prepared with good selectivity via the reaction of RCN with excess 3-hexyne under conditions that suppress AP. DFT calculations support a [2 + 2) cycloaddition-cycloreversion mechanism analogous to that of alkyne metathesis. The barrier to azametalacyciobutadiene ring formation/breakup is greater than that for the corresponding metalacyclobutadiene. Two distinct high-energy azametalacyclobutadiene intermediates were found. These adopted a distorted square pyramidal geometry with significant bond localization.

  DOI：

  10.1021/ja800020w

文献信息

• Catalytic Nitrile-Alkyne Cross-Metathesis
  作者：Andrea M. Geyer、Robyn L. Gdula、Eric S. Wiedner、Marc J. A. Johnson

  DOI：10.1021/ja0693439

  日期：2007.4.1

  The first catalytic cross-metathesis reaction of an alkyne with a nitrile is described. The nitride complex NW(OC(CF3)(2)CH3)(3)(DME) undergoes reversible triple-bond metathesis reactions with alkynes (RCCR; R = Et, 4-C6H4OMe), forming the alkylidyne complexes RCW(OC(CF3)(2)CH3)(3)(DME) (R = Et, 4-C6H4OMe) along with the corresponding nitrile RCN. This has been exploited to effect catalytic cross-metathesis of nitriles with alkynes, in which the organic CR fragments of two nitriles are coupled to yield an alkyne. A simple "sacrificial" alkyne (3-hexyne) acts as the N-atom acceptor, forming two equivalents of nitrile byproduct (propionitrile).
• Metathesis of acetylenes by (fluoroalkoxy)tungstenacyclobutadiene complexes and the crystal structure of W(C3Et3)[OCH(CF3)2]3. A higher order mechanism for acetylene metathesis
  作者：John H. Freudenberger、Richard R. Schrock、Melvyn Rowen Churchill、Arnold L. Rheingold、Joseph W. Ziller

  DOI：10.1021/om00088a019

  日期：1984.10