chloro(η4-1,5-cyclooctadiene)(1-butyl-3-methylimidazole-2-ylidene)rhodium(I)

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 唑类
• 英文名称: chloro(η4-1,5-cyclooctadiene)(1-butyl-3-methylimidazole-2-ylidene)rhodium(I)
• 英文别名: chloro(1,5-cyclooctadiene)(1-butyl-3-methylimidazole-2-ylidene)rhodium(I)；[RhCl(1-ⁿbutyl-3methylimidazol-2-ylidene)(1,8-cyclooctadiene)]；[RhCl(IBuMe)(COD)]；(1-butyl-3-methylimidazol-2-ylidene)-chlororhodium;(1Z,5Z)-cycloocta-1,5-diene
• 化学式: C₁₆H₂₆ClN₂Rh
• 分子量: 384.754
• InChiKey: JLFXVYZKSSPEHI-ONEVTFJLSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  5.07
• 重原子数：
  20
• 可旋转键数：
  3
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.56
• 拓扑面积：
  6.5
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为产物：
  描述：

  1-butyl-3-methylimidazolium-2-carboxylate 、 chloro(1,5-cyclooctadiene)rhodium(I) dimer 以 乙腈 为溶剂， 以90%的产率得到chloro(η4-1,5-cyclooctadiene)(1-butyl-3-methylimidazole-2-ylidene)rhodium(I)
  参考文献：
  名称：

  Hydrosilylation catalysed by a rhodium complex in a supercritical CO2/ionic liquid system

  摘要：

  在超临界二氧化碳（scCO2）/离子液体（IL）体系中研究了烯烃的氢硅化反应。Rh(PPh3)3Cl表现出优异的催化活性和选择性。KOtBu作为添加剂，在scCO2/IL体系中未检测到氢化副产物（烷烃）。在scCO2/IL体系中进行氢硅化反应时，反应物可能通过scCO2转移到IL相中，催化剂在该相中溶解。反应后，产物可通过scCO2冲洗，催化剂/IL体系可重复使用。

  DOI：

  10.1039/c0nj00012d

文献信息

• Synthesis of rhodium N-heterocyclic carbene complexes and their catalytic activity in the hydrosilylation of alkenes in ionic liquid medium
  作者：Jiayun Li、Jiajian Peng、Ying Bai、Guoqiao Lai、Xiaonian Li

  DOI：10.1016/j.jorganchem.2010.11.017

  日期：2011.5

  Rhodium complexes bearing N-heterocyclic carbene (NHC) ligands were prepared from bis(η4-1,5-cyclooctadiene) dichlorodirhodium and 1-alkyl-3-methylimidazolium-2-carboxylate, and the catalytic properties of rhodium complexes prepared in the hydrosilylation of alkenes in ionic liquid media were investigated. It was found that both the catalytic activity and selectivity of the rhodium complexes bearing

  铑络合物轴承ñ -杂环卡宾（NHC）配体从双制备（η 4 -1,5-环辛二烯）dichlorodirhodium和1-烷基-3-甲基咪唑-2-羧酸乙酯，和铑配合物的催化性能在氢化硅烷化制备的研究了离子液体介质中烯烃的结构。已经发现，带有NHC配体的铑配合物的催化活性和选择性都受到咪唑鎓阳离子附着的替代物的影响。此外，在离子液体BMimPF 6中带有NHC配体的铑配合物可以重复使用而不会明显降低催化活性和选择性。
• Imidazolium Carboxylates as Versatile and Selective N-Heterocyclic Carbene Transfer Agents:  Synthesis, Mechanism, and Applications
  作者：Adelina M. Voutchkova、Marta Feliz、Eric Clot、Odile Eisenstein、Robert H. Crabtree

  DOI：10.1021/ja0742885

  日期：2007.10.1

  N,N-Disubstituted imidazolium carboxylates, readily synthetically available, isolable, air- and water-stable reagents, efficiently transfer N-heterocyclic carbene (NHC) groups to Rh, Ir, Ru, Pt, and Pd, to give novel NHC complexes, e.g., [Pd(NHC)3OAc]OAc and [Pt(NHC)(3)CI]CI (NHC = 1,3-dimethyl imiclazol2-ylidene). The NHC esters are also effective. Tuning the reaction conditions for NHC transfer can give either mono- or bis-NHCs, or bis- and tris-NHCs. A net N to C rearrangement of the N-alkyl imidazole complex to the corresponding NHC complex was seen with (MeO)(2)CO (DMC). DFT calculations identify the steps needed to form the carboxylate from imidazole and DMC: S(N)2 methyl transfer from DMC to imidazole. followed by proton transfer from the imidazolium CH to the carboxylate counterion, produces the free NHC H-bonded to MeOH with a weakly associated CO2. The nucleophilic NHC attacks CO2 to form NHC-CO2. NHC transfer to the metal with loss of CO2 has been calculated for Rh(cod)CI. A proposed two-cis-site reactivity model rationalizes the experimental data: two such vacant sites at the metal are needed to allow coordination of the NHC-CO2 carboxylate and subsequent CC cleavage with NHC transfer. Partial cod decoordination or chloride loss is thus required for Rh(cod)CI. Chloride dissociation, calculated to be easier in polar solvent, is confirmed experimentally from the retarding effect of excess chloride.