Tris(3-methylphenyl)phosphine
[CAS# 6224-63-1]

Identification

• Classification: Organic raw materials >> Organic phosphine compound
• Name: Tris(3-methylphenyl)phosphine
• Synonyms: Tri(m-tolyl)phosphine
• Molecular Formula: C₂₁H₂₁P
• Molecular Weight: 304.36
• CAS Registry Number: 6224-63-1
• EC Number: 228-312-4
• SMILES: CC1=CC(=CC=C1)P(C2=CC=CC(=C2)C)C3=CC=CC(=C3)C

Properties

• Melting point: 97-99 ºC

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H315-H319-H335
• Precautionary Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+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
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovory and Applicatios

Tris(3-methylphenyl)phosphine is a specialized organophosphorus compound notable for its role as a ligand in various transition metal catalysis applications. Synthesized initially in the early 1970s, this compound was developed as part of research into creating ligands with distinct steric and electronic properties to influence metal-catalyzed reactions effectively. The synthesis of tris(3-methylphenyl)phosphine involves the reaction of phosphorus trichloride with 3-methylphenyl lithium or 3-methylphenyl Grignard reagents, followed by the treatment with a base to form the final phosphine derivative.

The compound is primarily utilized as a ligand in metal-catalyzed reactions due to its ability to stabilize metal centers through both steric and electronic interactions. The 3-methylphenyl groups attached to the phosphorus atom influence the reactivity and stability of metal complexes, thereby affecting the efficiency and selectivity of catalytic processes.

One significant application of tris(3-methylphenyl)phosphine is in hydrogenation reactions. In this context, the compound serves to stabilize transition metal catalysts, such as those based on palladium or platinum. The steric bulk provided by the 3-methylphenyl groups around the phosphorus atom creates a shielded environment around the metal center. This stabilization effect helps control the metal’s reactivity, leading to improved performance in the hydrogenation of various substrates, including alkenes and alkynes.

Tris(3-methylphenyl)phosphine is also valuable in cross-coupling reactions, where it acts as a ligand for palladium and nickel catalysts. The steric effects imparted by the 3-methylphenyl groups stabilize the metal-ligand complex, enhancing the efficiency and selectivity of cross-coupling processes. This application is particularly significant in the synthesis of complex organic molecules, where precise control over the coupling reaction is crucial for obtaining desired products.

Furthermore, tris(3-methylphenyl)phosphine finds use in other catalytic processes, including hydroformylation and carbonylation. Its ability to stabilize metal centers and influence reaction pathways makes it a versatile ligand in the development of new catalytic methods and materials. The compound’s role in these processes is a testament to its importance in advancing chemical synthesis and materials science.

Ongoing research continues to explore new applications and improvements for tris(3-methylphenyl)phosphine. Advances in catalytic science and synthetic methodologies may reveal further uses for this ligand, solidifying its role in both academic research and industrial applications. The continued exploration of its properties and applications underscores its significance in the field of organometallic chemistry.