Английская Википедия:Dichlorotris(triphenylphosphine)ruthenium(II)

Материал из Онлайн справочника
Перейти к навигацииПерейти к поиску

Шаблон:Chembox

Dichlorotris(triphenylphosphine)ruthenium(II) is a coordination complex of ruthenium. It is a chocolate brown solid that is soluble in organic solvents such as benzene. The compound is used as a precursor to other complexes including those used in homogeneous catalysis.

Synthesis and basic properties

RuCl2(PPh3)3 is the product of the reaction of ruthenium trichloride trihydrate with a methanolic solution of triphenylphosphine.[1][2]

2 RuCl3(H2O)3 + 7 PPh3 → 2 RuCl2(PPh3)3 + 2 HCl + 5 H2O + OPPh3

The coordination sphere of RuCl2(PPh3)3 can be viewed as either five-coordinate or octahedral. One coordination site is occupied by one of the hydrogen atoms of a phenyl group.[3] This Ru---H agostic interaction is long (2.59 Å) and weak. The low symmetry of the compound is reflected by the differing lengths of the Ru-P bonds: 2.374, 2.412, and 2.230 Å.[4] The Ru-Cl bond lengths are both 2.387 Å.

Reactions

In the presence of excess of triphenylphosphine, RuCl2(PPh3)3 binds a fourth phosphine to give black RuCl2(PPh3)4. The triphenylphosphine ligands in both the tris(phosphine) and tetrakis(phosphine) complexes are readily substituted by other ligands. The tetrakis(phosphine) complex is a precursor to the Grubbs catalysts.[5]

Dichlorotris(triphenylphosphine)ruthenium(II) reacts with hydrogen in the presence of base to give the purple-colored monohydride HRuCl(PPh3)3.[6]

RuCl2(PPh3)3 + H2 + NEt3 → HRuCl(PPh3)3 + [HNEt3]Cl

Dichlorotris(triphenylphosphine)ruthenium(II) reacts with carbon monoxide to produce the all trans isomer of dichloro(dicarbonyl)bis(triphenylphosphine)ruthenium(II).

RuCl2(PPh3)3 + 2 CO → trans,trans,trans-RuCl2(CO)2(PPh3)2 + PPh3

This kinetic product isomerizes to the cis adduct during recrystallization. trans-RuCl2(dppe)2 forms upon treating RuCl2(PPh3)3 with dppe.

RuCl2(PPh3)3 + 2 dppe → RuCl2(dppe)2 + 3 PPh3

RuCl2(PPh3)3 catalyzes the decomposition of formic acid into carbon dioxide and hydrogen gas in the presence of an amine.[7] Since carbon dioxide can be trapped and hydrogenated on an industrial scale, formic acid represents a potential storage and transportation medium.

Use in organic synthesis

RuCl2(PPh3)3 facilitates oxidations, reductions, cross-couplings, cyclizations, and isomerization. It is used in the Kharasch addition of chlorocarbons to alkenes.[8]

Файл:Kharasch Addition Dichlorotris(triphenylphosphine)ruthenium(II).png

Dichlorotris(triphenylphosphine)ruthenium(II) serves as a precatalyst for the hydrogenation of alkenes, nitro compounds, ketones, carboxylic acids, and imines. On the other hand, it catalyzes the oxidation of alkanes to tertiary alcohols, amides to t-butyldioxyamides, and tertiary amines to α-(t-butyldioxyamides) using tert-butyl hydroperoxide. Using other peroxides, oxygen, and acetone, the catalyst can oxidize alcohols to aldehydes or ketones. Using dichlorotris(triphenylphosphine)ruthenium(II) the N-alkylation of amines with alcohols is also possible (see "borrowing hydrogen").[8]

Файл:N-Alkylation.png

RuCl2(PPh3)3 efficiently catalyzes carbon-carbon bond formation from cross couplings of alcohols through C-H activation of sp3 carbon atoms in the presence of a Lewis acid.[9]

Файл:Alcohol Cross Coupling RuCl2PPH3.png

References

  1. ↑ Stephenson, T. A.; Wilkinson, G. "New Complexes of Ruthenium (II) and (III) with Triphenylphosphine, Triphenylarsine, Trichlorostannate, Pyridine, and other Ligands", J. Inorg. Nucl. Chem., 1966, 28, 945-956. Шаблон:Doi
  2. ↑ P. S. Hallman, T. A. Stephenson, G. Wilkinson "Tetrakis(Triphenylphosphine)Dichloro-Ruthenium(II) and Tris(Triphenylphosphine)-Dichlororuthenium(II)" Inorganic Syntheses, 1970 volume 12 Шаблон:Doi
  3. ↑ Sabo-Etienne, S.; Gellier, M., "Ruthenium: Inorganic and Coordination Chemistry", Encyclopedia of Inorganic Chemistry, 2006, John Wiley & Sons Шаблон:Cite book
  4. ↑ Шаблон:Cite journal
  5. ↑ Georgios C. Vougioukalakis, Robert H. Grubbs "Ruthenium-Based Heterocyclic Carbene-Coordinated Olefin Metathesis Catalysts" Chem. Rev., 2010, volume 110, pp 1746–1787 Шаблон:Cite journal
  6. ↑ Шаблон:Cite book
  7. ↑ Loges, B.; Boddien, A.; Junge, H.; Beller, M., "Controlled Generation of Hydrogen from Formic Acid Amine Adducs at Room Temperature and Application in H2/O2 Fuel Cells", Angew. Chem. Int. Ed., 2008, 47, 3962-3965 Шаблон:Cite journal
  8. ↑ 8,0 8,1 Plummer, J. S.; Shun-Ichi, M.; Changjia, Z. "Dichlorotris(triphenylphosphine)ruthenium(II)", e-EROS Encyclopedia of Reagents for Organic Synthesis, 2010, John Wiley Шаблон:Doi
  9. ↑ Shu-Yu, Z.; Yong-Qiang, T.; Chun-An, F.; Yi-Jun, J.; Lei, S.; Ke, C.; En, Z.; "Cross-Coupling Reactions between alcohols through sp3 C-H Activation Catalyzed by a Ruthenium/Lewis Acid System" Chem. Eur. J., 2008, 14, 10201-10205 Шаблон:Cite journal

Шаблон:Ruthenium compounds

Партнерские ресурсы
Криптовалюты
Магазины
Хостинг
Разное

Источник — http://wikihandbk.com/ruwiki/index.php?title=Английская_Википедия:Dichlorotris(triphenylphosphine)ruthenium(II)&oldid=14298418