1,1'-Bis(diphenylphosphino)ferrocene
Encyclopedia
1,1'-Bisferrocene, commonly abbreviated dppf, is a substituted phosphine
commonly used, as are other phosphines, as a ligand
in organometallic chemistry
. It contains a ferrocene
moiety in its backbone, and is closely related to other bridged diphenylphosphines such as 1,1-bis(diphenylphosphino)methane
(dppm) and 1,2-bis(diphenylphosphino)ethane
(dppe).
with n-butyllithium
in the presence of TMEDA, followed by reaction with chlorodiphenylphosphine
:
is especially popular for palladium-catalyzed coupling reactions
. It is easily prepared in the usual manner, by reaction of dppf with the acetonitrile or benzonitrile complexes of palladium dichloride:
Phosphine
Phosphine is the compound with the chemical formula PH3. It is a colorless, flammable, toxic gas. Pure phosphine is odourless, but technical grade samples have a highly unpleasant odor like garlic or rotting fish, due to the presence of substituted phosphine and diphosphine...
commonly used, as are other phosphines, as a 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...
in organometallic chemistry
Organometallic chemistry
Organometallic chemistry is the study of chemical compounds containing bonds between carbon and a metal. Since many compounds without such bonds are chemically similar, an alternative may be compounds containing metal-element bonds of a largely covalent character...
. It contains a ferrocene
Ferrocene
Ferrocene is an organometallic compound with the formula Fe2. It is the prototypical metallocene, a type of organometallic chemical compound consisting of two cyclopentadienyl rings bound on opposite sides of a central metal atom. Such organometallic compounds are also known as sandwich compounds...
moiety in its backbone, and is closely related to other bridged diphenylphosphines such as 1,1-bis(diphenylphosphino)methane
1,1-Bis(diphenylphosphino)methane
1,1-Bismethane , is an organophosphorus compound with the formula CH22. Dppm, a white, crystalline powder, is used in inorganic and organometallic chemistry as a ligand...
(dppm) and 1,2-bis(diphenylphosphino)ethane
1,2-Bis(diphenylphosphino)ethane
1,2-Bisethane is a commonly used bidentate ligand in coordination chemistry. Dppe is almost invariably chelated, although there are examples of unidentate and of bridging behavior.-Preparation:...
(dppe).
Preparation
This compound is commercially available. It may be prepared by the lithiation of ferroceneFerrocene
Ferrocene is an organometallic compound with the formula Fe2. It is the prototypical metallocene, a type of organometallic chemical compound consisting of two cyclopentadienyl rings bound on opposite sides of a central metal atom. Such organometallic compounds are also known as sandwich compounds...
with n-butyllithium
N-Butyllithium
n-Butyllithium is an organolithium reagent. It is widely used as a polymerization initiator in the production of elastomers such as polybutadiene or styrene-butadiene-styrene...
in the presence of TMEDA, followed by reaction with chlorodiphenylphosphine
Chlorodiphenylphosphine
Chlorodiphenylphosphine is an organophosphorus compound with the formula 2PCl, abbreviated Ph2PCl. It is a colourless oily liquid with a pungent odor that is often described as being garlic-like and detectable even in the ppb range. It is useful reagent for introducing the Ph2P group into...
:
Reactions
Dppf readily forms complexes with various metals; the palladium derivative, (dppf)PdCl2(1,1'-Bis(diphenylphosphino)ferrocene)palladium(II) dichloride
[1,1'-Bisferrocene]palladium dichloride is an palladium complex containing the iron-containing dppf ligand. Commercially available, this compound is popularly used for palladium-catalyzed coupling reactions....
is especially popular for palladium-catalyzed coupling reactions
Palladium-catalyzed coupling reactions
Palladium compounds are used as a catalyst in many coupling reactions, usually as a homogeneous catalyst. Examples include:* Heck reaction between alkenes and aryl halides* Suzuki reaction between aryl halides and boronic acids...
. It is easily prepared in the usual manner, by reaction of dppf with the acetonitrile or benzonitrile complexes of palladium dichloride:
- dppf + PdCl2(RCN)2 → (dppf)PdCl2 + 2 RCN (RCN = acetonitrileAcetonitrileAcetonitrile is the chemical compound with formula . This colourless liquid is the simplest organic nitrile. It is produced mainly as a byproduct of acrylonitrile manufacture...
or benzonitrileBenzonitrileBenzonitrile is the chemical compound with the formula C6H5CN, abbreviated PhCN. This aromatic organic compound is colourless, with a sweet almond odour. It is prepared by the dehydration of benzamide, or by the reaction of sodium cyanide with bromobenzene....
)