1,2-Bis(diphenylphosphino)ethane
[CAS# 1663-45-2]

Identification

• Classification: Organic raw materials >> Organic phosphine compound
• Name: 1,2-Bis(diphenylphosphino)ethane
• Synonyms: Bis(1,2-diphenylphosphino)ethane; Ethylenebis(diphenylphosphine)
• Molecular Formula: C₂₆H₂₄P₂
• Molecular Weight: 398.42
• CAS Registry Number: 1663-45-2
• EC Number: 216-769-2
• SMILES: C1=CC=C(C=C1)P(CCP(C2=CC=CC=C2)C3=CC=CC=C3)C4=CC=CC=C4

Properties

• Melting point: 138-142 °C

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Risk Statements: H315-H319-H335-H400-H410
• Safety Statements: P261-P264-P264+P265-P271-P273-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P391-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

1,2-Bis(diphenylphosphino)ethane, commonly abbreviated as DPPE, is a versatile and widely used organophosphorus compound notable for its applications in catalysis and coordination chemistry. First synthesized in the 1960s, DPPE has since become a fundamental ligand in the development of various catalytic systems, particularly in the realm of transition metal chemistry.

The discovery of DPPE marked a significant advancement in the design of bidentate ligands. The structure of DPPE consists of two diphenylphosphino groups attached to a central ethane bridge. This arrangement provides the ligand with a chelating capability, allowing it to form stable complexes with transition metals. The bidentate nature of DPPE ensures that it binds through two phosphorus atoms, creating a strong and stable coordination environment around the metal center.

DPPE is predominantly used in the synthesis of organometallic complexes, where its ability to stabilize metal centers is highly valued. One of its most notable applications is in catalysis, particularly in the context of hydroformylation reactions. In hydroformylation, DPPE-containing rhodium complexes are employed to convert alkenes into aldehydes with high regioselectivity and efficiency. The ligand's ability to provide a stable coordination environment around the rhodium center enhances the catalyst's performance and extends its operational lifespan.

Another significant application of DPPE is in the field of asymmetric synthesis. In chiral catalysis, DPPE can be used to prepare enantioselective catalysts, which are essential for producing chiral compounds with high purity. These catalysts are crucial in the pharmaceutical industry for synthesizing drugs and other biologically active molecules.

DPPE is also utilized in cross-coupling reactions, such as the Suzuki and Negishi couplings. In these reactions, DPPE complexes with palladium or nickel serve as effective catalysts for forming carbon-carbon bonds. The stability provided by the DPPE ligand contributes to the overall efficiency of the coupling reactions, enabling the synthesis of complex organic molecules.

The versatility of DPPE extends beyond traditional catalysis. The ligand is also used in the development of materials and in the study of metal-ligand interactions. Its ability to form stable complexes with a wide range of transition metals makes it a valuable tool for exploring the reactivity and properties of various metal centers.

In summary, 1,2-Bis(diphenylphosphino)ethane is a crucial compound in organometallic chemistry and catalysis. Its discovery has paved the way for numerous advancements in catalytic processes and materials science. As research continues, the applications of DPPE are likely to expand, further enhancing its role in chemical synthesis and industrial applications.

References

2007. Palladium-Catalyzed Selective Cross-Addition of Triisopropylsilylacetylene to Internal and Terminal Unactivated Alkynes. Organic Letters.
DOI: 10.1021/ol071326g

2002. Metal-Template-Directed Synthesis of Diphosphorus Compounds through Intramolecular Phosphinidene Additions. Chemistry (Weinheim an der Bergstrasse, Germany).
DOI: 10.1002/1521-3765(20020104)8:1<58::aid-chem58>3.0.co;2-5

2013. Oxygenation of Ruthenium Carbene Complexes Containing Naphthothiophene or Naphthofuran: Spectroscopic and DFT Studies. Chemistry - An Asian Journal.
DOI: 10.1002/asia.201300726