Cyclohexyldiphenylphosphine
[CAS# 6372-42-5]

Identification

• Classification: Organic raw materials >> Organic phosphine compound
• Name: Cyclohexyldiphenylphosphine
• Synonyms: Cyclohexyl diphenyl phosphine
• Molecular Formula: C₁₈H₂₁P
• Molecular Weight: 268.34
• CAS Registry Number: 6372-42-5
• EC Number: 228-904-2
• SMILES: C1CCC(CC1)P(C2=CC=CC=C2)C3=CC=CC=C3

Properties

• Melting point: 58-62 ºC
• Water solubility: insoluble
• Flash point: 110 ºC

Safety Data

• Hazard Symbols: GHS07;GHS08 Warning
• Hazard Statements: H302-H315-H317-H319-H335-H373-H413
• Precautionary Statements: P260-P261-P264-P264+P265-P270-P271-P272-P273-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P319-P321-P330-P332+P317-P333+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Skin sensitization	Skin Sens.	1	H317
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovory and Applicatios

Cyclohexyldiphenylphosphine is an organophosphorus compound that has garnered attention for its versatility and effectiveness as a ligand in various catalytic processes. The substance is characterized by a phosphine group bonded to a cyclohexyl group and two phenyl groups, providing a unique combination of steric and electronic properties. The synthesis and discovery of cyclohexyldiphenylphosphine can be traced back to advancements in organophosphorus chemistry, where researchers sought to create ligands that could enhance the performance of transition metal catalysts.

The synthesis of cyclohexyldiphenylphosphine typically involves the reaction of cyclohexylmagnesium bromide with chlorodiphenylphosphine. This Grignard reaction proceeds under controlled conditions to produce cyclohexyldiphenylphosphine in high yield. The resultant compound is a white to pale yellow solid that is soluble in organic solvents, making it suitable for use in a variety of catalytic systems.

Cyclohexyldiphenylphosphine is primarily employed as a ligand in transition metal-catalyzed reactions. Its unique structure, which combines the bulky cyclohexyl group with two phenyl groups, allows it to exert both steric and electronic effects on the metal center to which it is coordinated. This dual influence makes the ligand particularly valuable in fine-tuning the reactivity and selectivity of catalytic processes.

One of the most notable applications of cyclohexyldiphenylphosphine is in palladium-catalyzed cross-coupling reactions, such as the Suzuki-Miyaura and Heck reactions. In these reactions, the ligand stabilizes the palladium catalyst, enhances its activity, and improves the selectivity of the reaction. The steric bulk provided by the cyclohexyl group helps to prevent unwanted side reactions, while the phenyl groups contribute to the electronic environment of the palladium center, facilitating the desired transformations.

In addition to its use in palladium-catalyzed reactions, cyclohexyldiphenylphosphine has also been employed in other metal-catalyzed processes, including hydrogenation and hydroformylation. In these applications, the ligand's ability to modulate the electronic properties of the metal center is critical to achieving high catalytic efficiency and selectivity. The ligand's effectiveness in these reactions has made it a valuable tool in both academic research and industrial applications, particularly in the synthesis of complex organic molecules.

The discovery and application of cyclohexyldiphenylphosphine have had a significant impact on the field of organometallic chemistry. By providing a ligand that can enhance the performance of a wide range of catalytic processes, cyclohexyldiphenylphosphine has contributed to the development of more efficient and selective synthetic methodologies. Its role in facilitating complex organic transformations continues to make it a critical component in the toolkit of chemists working in both research and industry.

References

2000. Thermal Decomposition of Trialkyl/Arylphosphine Gold(I) Cyanide Complexes. Journal of Thermal Analysis and Calorimetry, 60(1).
DOI: 10.1023/a:1010164725008

2011. Synthesis of Phosphorus Compounds via Metal-Catalyzed Addition of P-H Bond to Unsaturated Organic Molecules. Catalysis by Metal Complexes.
DOI: 10.1007/978-90-481-3817-3_8

2015. Synthesis, spectroscopic characterization, and crystal structures of diiron pentacarbonyl complexes with monosubstituted tris(3-chlorophenyl)phosphine or cyclohexyldiphenylphosphine ligands. Transition Metal Chemistry, 40(8).
DOI: 10.1007/s11243-015-9989-z