Bis(triphenylphosphine)palladium(II) Chloride on:
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Bis(triphenylphosphine)palladium chloride is a
The Suzuki reaction was once limited by high levels of catalyst and the limited availability of boronic acids. Replacements for halides were also found, increasing the number of coupling partners for the halide or pseudohalide as well. Using bis(triphenylphosphine)palladium chloride as the catalyst, triflates and
coordination compound
A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many ...
of palladium
Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas, which was itself na ...
containing two triphenylphosphine
Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C6H5)3 and often abbreviated to P Ph3 or Ph3P. It is widely used in the synthesis of organic and organometallic compounds. PPh3 exists a ...
and two chloride
The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride salts ...
ligands. It is a yellow solid that is soluble in some organic solvents. It is used for palladium-catalyzed coupling reactions, e.g. the Sonogashira–Hagihara reaction. The complex is square planar
The square planar molecular geometry in chemistry describes the stereochemistry (spatial arrangement of atoms) that is adopted by certain chemical compounds. As the name suggests, molecules of this geometry have their atoms positioned at the corne ...
. Many analogous complexes are known with different phosphine ligands.
Preparation and reactions
This compound may be prepared by treating palladium(II) chloride withtriphenylphosphine
Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C6H5)3 and often abbreviated to P Ph3 or Ph3P. It is widely used in the synthesis of organic and organometallic compounds. PPh3 exists a ...
:
:PdCl2 + 2 PPh3 → PdCl2(PPh3)2
Upon reduction with hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine ...
in the presence of excess triphenylphosphine, the complex is a precursor to tetrakis(triphenylphosphine)palladium
Tetrakis(triphenylphosphine)palladium(0) (sometimes called quatrotriphenylphosphine palladium) is the chemical compound d(P(C6H5)3)4 often abbreviated palladium, Pd(triphenylphosphine, PPh3)4, or rarely PdP4. It is a bright yellow crystalline ...
, Pd(PPh3)4:
:2 PdCl2(PPh3)2 + 4 PPh3 + 5 N2H4 → 2 Pd(PPh3)4 + N2 + 4 N2H5+Cl−
Structure
Severalcrystal structure
In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystal, crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric pat ...
s containing PdCl2(PPh3)2 have been reported. In all of the structures, PdCl2(PPh3)2 adopts a square planar coordination geometry and the ''trans'' isomeric form.
Applications
The complex is used as a pre-catalyst for a variety of coupling reactions.
The Suzuki reaction was once limited by high levels of catalyst and the limited availability of boronic acids. Replacements for halides were also found, increasing the number of coupling partners for the halide or pseudohalide as well. Using bis(triphenylphosphine)palladium chloride as the catalyst, triflates and boronic acids
A boronic acid is an organic compound related to boric acid () in which one of the three hydroxyl groups () is replaced by an alkyl or aryl group (represented by R in the general formula ). As a compound containing a carbon–boron bond, membe ...
have been coupled on an 80 kilogram scale in good yield. The same catalyst is effective for the Sonogashira coupling
The Sonogashira reaction is a cross-coupling reaction used in organic synthesis to form carbon–carbon bonds. It employs a palladium catalyst as well as copper co-catalyst to form a carbon–carbon bond between a terminal alkyne and an aryl or vi ...
.
See also
*Bis(triphenylphosphine)platinum(II) chloride
Bis(triphenylphosphine)platinum chloride is a metal phosphine complex with the formula PtCl2 (C6H5)3sub>2. Cis- and trans isomers are known. The cis isomer is a white crystalline powder, while the trans isomer is yellow. Both isomers are square ...
* Bis(triphenylphosphine)nickel(II) chloride
References