Bis(triphenylphosphine)palladium(II) chloride
[CAS# 13965-03-2]

Identification

• Classification: Organic raw materials >> Organometallic compound >> Organic palladium
• Name: Bis(triphenylphosphine)palladium(II) chloride
• Synonyms: Dichlorobis(triphenylphosphine)palladium(II); Palladium(II)bis(triphenylphosphine) dichloride
• Molecular Formula: C₃₆H₃₀Cl₂P₂Pd
• Molecular Weight: 701.91
• CAS Registry Number: 13965-03-2
• EC Number: 237-744-2
• SMILES: C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.Cl[Pd]Cl

Properties

• Solubility: Soluble (chloroform, hexane toluene)
• Melting point: 310 °C (decomp.)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H315-H317-H319-H413
• Safety Statements: P261-P264-P264+P265-P270-P272-P273-P280-P301+P317-P302+P352-P305+P351+P338-P321-P330-P332+P317-P333+P317-P337+P317-P362+P364-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Skin sensitization	Skin Sens.	1A	H317
Skin irritation	Skin Irrit.	2	H315
Skin sensitization	Skin Sens.	1	H317
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	4	H302
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H312
Eye irritation	Eye Irrit.	2A	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400

Discovery and Applications

Bis(triphenylphosphine)palladium(II) chloride, often abbreviated as Pd(PPh3)2Cl2, is a widely studied organometallic compound. The synthesis of bis(triphenylphosphine)palladium(II) chloride was first reported in the mid-20th century when chemists were exploring the coordination chemistry of palladium with phosphine ligands. The compound is typically prepared by reacting palladium(II) chloride with triphenylphosphine in a suitable solvent under controlled conditions. The reaction forms a deep red crystalline solid characterized by unique catalytic and organic transformation properties. The chemical formula of bis(triphenylphosphine)palladium(II) chloride is Pd(PPh₃)₂Cl₂. It consists of a palladium ion (Pd²⁺) coordinated to two triphenylphosphine (PPh₃) ligands and two chloride ions (Cl⁻) in a square planar geometry. This molecular structure confers stability and reactivity, making it an effective catalyst in a variety of reactions. The compound is slightly soluble in polar solvents such as acetone and dichloromethane, but more soluble in nonpolar solvents such as benzene and toluene. It is stable under ambient conditions but is sensitive to air and moisture and needs to be handled under an inert atmosphere for preservation. Bis(triphenylphosphine)palladium(II) chloride is valued for its catalytic properties, especially in palladium-catalyzed cross-coupling reactions. The chloride ion can be replaced by other ligands, which affects the reactivity and selectivity of the compound in different catalytic processes.

Pd(PPh₃)₂Cl₂ is an important catalyst in the Suzuki-Miyaura coupling reaction, which forms aryl-aryl, aryl-vinyl, and aryl-alkyl bonds under mild conditions. This reaction is essential for building complex molecular structures in drug synthesis, material science, and agrochemical production. It catalyzes the Heck reaction, which promotes the coupling of aryl halides with alkenes to form substituted alkenes. This transformation is important for modifying natural products and designing functional materials with specific electronic and structural properties. Pd(PPh₃)₂Cl₂ is used in the Mizoroki-Heck reaction to couple aryl halides with alkynes or alkenes in the presence of carbon monoxide (CO). The process leads to the synthesis of α,β-unsaturated carbonyl compounds, which are key intermediates in the production of pharmaceuticals and fine chemicals. It is used as a catalyst for hydrogenation reactions, promoting the reduction of alkenes, alkynes, and carbonyl compounds to the corresponding saturated derivatives. This catalytic ability is crucial in the production of chiral compounds for pharmaceuticals and in industrial processes for the conversion of unsaturated hydrocarbons.

Bis(triphenylphosphine)palladium(II) chloride and its derivatives are immobilized on solid supports or nanoparticle surfaces for heterogeneous catalysis. This application improves the recyclability, stability, and efficiency of the catalyst in large-scale industrial processes.

References

2024. Synthetic studies on the tetrasubstituted D-ring of cystobactamids lead to potent terephthalic acid antibiotics. Communications Chemistry.
DOI: 10.1038/s42004-024-01337-6

2015. Palladium-Catalyzed Carbonylative Synthesis of Six-Membered Heterocycles from Aryl Halides. Transition Metal Catalyzed Carbonylative Synthesis of Heterocycles.
DOI: 10.1007/7081_2015_150

2012. Metalation Reactions of Isoxazoles and Benzisoxazoles. Metalation of Azoles and Related Five-Membered Ring Heterocycles.
DOI: 10.1007/7081_2012_80