Shvo catalyst
Encyclopedia
The Shvo catalyst, named after Youval Shvo, is an organoruthenium compound that is used for transfer hydrogenation
. Related derivatives are known where p-tolyl
replaces some of the phenyl groups.
and triruthenium dodecacarbonyl
.This synthetic route is efficient, despite the complicated pathway, which includes formation of cyclopentadienone-like ligand
s. The compound contains a pair of equivalent Ru centres that are bridged by a strong hydrogen bond and a bridging
hydride.
In solution, the complex dissociates unsymmetrically:2HRu2H(CO)4 → (η5-C5Ph4OH)RuH(CO)2 + (η6-C5Ph4O)Ru(CO)2
The hydride (η5-C5Ph4OH)RuH(CO)2 transfers H2, especially to polar substrates such as ketones and iminium cations. The cyclopentadienone species (η6-C5Ph4O)Ru(CO)2 abstracts H2 from substrates.
Transfer hydrogenation
Transfer hydrogenation is the addition of hydrogen to a molecule from a source other than gaseous H2. It is applied in industry and in organic synthesis, in part because of the inconvenience and expense of using gaseous H2...
. Related derivatives are known where p-tolyl
Toluene
Toluene, formerly known as toluol, is a clear, water-insoluble liquid with the typical smell of paint thinners. It is a mono-substituted benzene derivative, i.e., one in which a single hydrogen atom from the benzene molecule has been replaced by a univalent group, in this case CH3.It is an aromatic...
replaces some of the phenyl groups.
Synthesis, structure, reactivity
The complex is prepared by the reaction of diphenylacetyleneDiphenylacetylene
Diphenylacetylene is the chemical compound C6H5C≡CC6H5. The molecule consists of phenyl groups attached to both ends of an alkyne. It is a colorless crystalline material that is widely used as a building block in organic and as a ligand in organometallic chemistry.-Preparation:Several...
and triruthenium dodecacarbonyl
Triruthenium dodecacarbonyl
Triruthenium dodecacarbonyl is the chemical compound with the formula Ru312. This orange-colored metal carbonyl cluster is a precursor to other organoruthenium compounds.-Structure and synthesis:...
.This synthetic route is efficient, despite the complicated pathway, which includes formation of cyclopentadienone-like ligand
Ligand
In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from...
s. The compound contains a pair of equivalent Ru centres that are bridged by a strong hydrogen bond and a bridging
Bridging ligand
A bridging ligand is a ligand that connects two or more atoms, usually metal ions. The ligand may be atomic or polyatomic. Virtually all complex organic compounds can serve as bridging ligands, so the term is usually restricted to small ligands such as pseudohalides or to ligands that are...
hydride.
In solution, the complex dissociates unsymmetrically:2HRu2H(CO)4 → (η5-C5Ph4OH)RuH(CO)2 + (η6-C5Ph4O)Ru(CO)2
The hydride (η5-C5Ph4OH)RuH(CO)2 transfers H2, especially to polar substrates such as ketones and iminium cations. The cyclopentadienone species (η6-C5Ph4O)Ru(CO)2 abstracts H2 from substrates.