pentacarbonyl(isopropylmethoxycarbene)chromium(0)

• 分子结构分类: 有机化合物 - 有机盐 - 有机金属盐
• 英文名称: pentacarbonyl(isopropylmethoxycarbene)chromium(0)
• 英文别名: (ethylmethoxycarbene)pentacarbonylchromium(0)；[(CO)5Cr=C(OMe)CH(CH3)2]；Carbon monoxide;(1-methoxy-2-methylpropylidene)chromium
• 化学式: C₁₀H₁₀CrO₆
• 分子量: 278.182
• InChiKey: URNPRWNGOAHFEQ-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  0.78
• 重原子数：
  17
• 可旋转键数：
  2
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.4
• 拓扑面积：
  14.2
• 氢给体数：
  0
• 氢受体数：
  6

反应信息

• 作为反应物：
  描述：

  pentacarbonyl(isopropylmethoxycarbene)chromium(0) 、 4-三氟甲氧基苯乙炔 在 palladium(II) trifluoroacetate 、 三(2-呋喃基)膦 、 2,5-联苯对苯醌 、 四丁基三氟甲磺酸铵 、 三乙胺 作用下， 以 甲苯 为溶剂， 反应 6.0h， 生成
  参考文献：
  名称：

  Pd催化末端炔烃与铬（0）费歇尔卡宾配合物的交叉偶联

  摘要：

  烷基铬（0）卡宾配合物通常与炔烃进行环加成反应，得到碳或杂环化合物。在钯催化剂的存在下，表明传统的环加成途径被完全改变：取代环加成，发生烷基铬（0）卡宾配合物与末端炔烃的氧化交叉偶联反应。偶联反应表现出优异的官能团耐受性和良好的效率。

  DOI：

  10.1021/acs.orglett.7b01096
• 作为产物：
  描述：

  五羰基(1-甲氧基亚乙基)-铬 在 正丁基锂 、 三氟甲烷磺酸甲酯 作用下， 以 乙醚 、 正己烷 为溶剂， 以42%的产率得到pentacarbonyl(isopropylmethoxycarbene)chromium(0)
  参考文献：
  名称：

  铬卡宾配合物与炔烃反应中氢活化形成环戊烯酮

  摘要：

  已发现烷基铬卡宾配合物与炔烃的反应得到环戊烯酮。提出了一些机制来解释这些涉及金属氢化物中间体的产物的形成。正如之前对钨所报道的那样，已经发现钼烷基配合物产生 1,3-二烯而不是环戊烯酮。铬与钼和钨之间的区别可能在于金属氢化物中间体可以在铬的情况下重新添加到烯烃中而不是进行还原消除

  DOI：

  10.1021/ja00057a020

文献信息

• Pd-catalyzed Oxidative Cross-coupling of Alkyl Chromium(0) Fischer Carbene Complexes with Organoboronic Acids
  作者：Kang Wang、Jinghui Yang、Xingqi Yao、Jianbo Wang

  DOI：10.1002/asia.201801278

  日期：2018.11.2

  Alkyl chromium(0) carbene complexes have been explored as the cross‐coupling partners in the palladium‐catalyzed reaction with aryl or alkenyl boronic acids. This coupling reaction displays the versatile reactivities of alkyl chromium(0) carbenes under palladium catalysis. Mechanistically, this transformation is proposed to involve deprotonation of the alkyl chromium carbene substrate to generate a

  烷基铬（0）卡宾配合物已被探索为钯与芳基或烯基硼酸催化的交叉偶联伙伴。此偶联反应显示了钯催化下烷基铬（0）卡宾的通用反应性。从机理上讲，提出这种转变涉及烷基铬卡宾底物的去质子化以产生乙烯基铬阴离子中间体，该中间体经历金属转移成有机钯物质并还原消除。
• A new synthetic route to Lindqvist type clusters [(n-Bu4N)x][M′M5O19] [when x = 2, M′ = M = Mo or W; x = 3, M′ = Mo, M = W] from metal carbonyl precursors [(CO)5ML] [M = Mo, W; L= CO, C(OMe)(Me)]
  作者：Arunabha Thakur、Amarnath Chakraborty、V. Ramkumar、Sundargopal Ghosh

  DOI：10.1039/b908348k

  日期：——

  Fischer carbene complexes, [(CO)5M=C(OMe)Me] (M = Mo, W) in yields of 73, 77 and 71% respectively. All the clusters have been characterized by IR, 1H and 13C NMR spectra, and crystal structure determinations. Additionally, the composition of 9 has also been supported by mass spectrometry (MALDI-TOF), inductively coupled plasma (ICP) and energy-dispersive X-ray (EDX) analysis. This novel and mild route

  两个完全氧化的[（n-Bu4N）2] [Mo6O19]，7和[（n-Bu4N）2] [W6O19]，8和一个混合金属，化合价一个电子被还原[[n-Bu4N）3]。 [MoW5O19]在双相反应条件下从VI族金属羰基化合物或菲舍尔卡宾配合物合成了9个簇，[（CO）5M = C（OMe）Me]（M = Mo，W）的收率分别为73、77和71 ％ 分别。所有团簇均通过IR，1H和13C NMR光谱以及晶体结构测定来表征。此外，质谱仪（MALDI-TOF），电感耦合等离子体（ICP）和能量色散X射线（EDX）分析也支持了9的组成。这种新颖而温和的路线比Lindqvist型混合价混合金属多金属氧酸盐簇的早期合成方法提供了明显的改进。
• Stadtmüller, Heinz; Knochel, Paul, Organometallics, 1995, vol. 14, # 7, p. 3163 - 3166
  作者：Stadtmüller, Heinz、Knochel, Paul

  DOI：——

  日期：——
• Physical Organic Chemistry of Transition Metal Carbene Complexes. 10.¹ Opposing Effects of α-Alkyl Groups on the Thermodynamic and Kinetic Acidities of (CO)₅CrC(OMe)CHR‘R‘‘-Type Fischer Carbene Complexes in Aqueous Acetonitrile. Analogy to the Nitroalkane Anomaly
  作者：Claude F. Bernasconi、Weitao Sun、Luis Garcia-Río、Kin Yan、Kevin Kittredge

  DOI：10.1021/ja970193z

  日期：1997.6.1

  The thermodynamic acidities of (CO)(5)Cr=C(OMe)CH2CH3 (3-Et), (CO)(5)Cr=C(OMe)CH2CH2CH2CH3 (3-Bu), and (CO)(5)Cr=C(OMe)CH(CH3)(2) (3-Pr) have been determined in 50% acetonitrile-50% water (v/v) at 25 degrees C; after applying statistical corrections, the pK(a) values are 12.62 for 3-Et, 12.84 for 3-Bu, and 12.27 for 3-Pr. These pK(a) values are all lower than pK(a) = 12.98 for (CO)(5)Cr=C(OMe)CH3 (3-Me) determined previously and give an acidity order of 3-Me < 3-Bu < 3-Et < 3-Pr. if it is assumed that the main resonance structure of the conjugate anions of the carbene complexes has the negative charge delocalized onto the (CO)(5)Cr moiety (e.g., 3-Et-: (CO)(5) (C) over bar rC(OMe)=CHCH3), the increased acidity with increasing alkyl substitution on the ct-carbon can be understood as reflecting the well-known stabilization of alkenes by alkyl groups. Rate constants for the deprotonation of 3-Et, 3-Bu, and 3-Pr by OH- and by piperidine are also reported and compared with the corresponding rate constants for 3-Me obtained previously. They follow the order 3-Me > 3-Et > 3-Bu > 3-Pr, essentially opposite to the order of the thermodynamic acidities. This leads to negative Bronsted a-values which are reminiscent of the nitroalkane anomaly. The observed kinetic order is the result of a lowering of the intrinsic rate constant by alkyl substitution. Four factors are identified that contribute to this lowering. (1) The disproportionately weak development of the C=C double bond at the transition state which prevents the latter from significantly benefiting from the alkene-stabilizing effect of the alkyl groups. (2) The disproportionately large negative charge on the a-carbon at the transition state that leads to a disproportionately strong destabilization of the transition state by the inductive/field effect of the alkyl groups relative to that of the product anion. (3) The destabilizing field effect of the alkyl groups on the partial negative charge on the hydroxide ion at the transition state. (4) Steric crowding at the transition state. Kinetic data on the hydrolysis of 3-Et, 3-Bu, and 3-Pr over a wide pH range are also reported. They support a previously proposed mechanism that involves rate limiting protonation of the conjugate anion of the carbene complex that is concerted with cleavage of the bond between the carbene carbon and the metal. With 3-Pr the hydrolysis is subject to catalysis by light.