Bis(1,1-dimethylethyl)[4-methoxy-3,5,6-trimethyl-2',4',6'-tris(1-methylethyl)[1,1'-biphenyl]-2-yl]phosphine
[CAS# 1359986-21-2]

Identification

• Classification: Organic raw materials >> Aryl compounds >> Biphenyl compounds
• Name: Bis(1,1-dimethylethyl)[4-methoxy-3,5,6-trimethyl-2',4',6'-tris(1-methylethyl)[1,1'-biphenyl]-2-yl]phosphine
• Synonyms: ditert-butyl-[3-methoxy-2,4,5-trimethyl-6-[2,4,6-tri(propan-2-yl)phenyl]phenyl]phosphane
• Molecular Formula: C₃₃H₅₃OP
• Molecular Weight: 496.75
• CAS Registry Number: 1359986-21-2
• EC Number: 811-518-9
• SMILES: CC1=C(C(=C(C(=C1C2=C(C=C(C=C2C(C)C)C(C)C)C(C)C)P(C(C)(C)C)C(C)(C)C)C)OC)C

Properties

• Solubility: Insoluble (1.9E^-6 g/L) (25 ºC), Calc.^*
• Boiling Point: 540.8±50.0 ºC (760 mmHg), Calc.^*
• Flash Point: 352.2±30.4 ºC, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

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

Discovory and Applicatios

Bis(1,1-dimethylethyl)[4-methoxy-3,5,6-trimethyl-2',4',6'-tris(1-methylethyl)[1,1'-biphenyl]-2-yl]phosphine, commonly known as a bulky phosphine ligand, is a notable compound in the field of organometallic chemistry. This compound is distinguished by its complex structure and the bulkiness of its substituents, which confer unique steric and electronic properties valuable for catalysis.

The discovery of this phosphine ligand emerged from the need to develop more effective and selective catalysts for various chemical reactions. The ligand is synthesized through the reaction of 1,1-dimethylethyl groups with a tri-substituted biphenyl core. The core features a 4-methoxy-3,5,6-trimethyl substitution pattern on the biphenyl ring, further decorated with bulky 1-methylethyl groups. This elaborate design aims to enhance the ligand’s steric environment, which can significantly influence the reactivity and selectivity of metal-catalyzed processes (Smith, R. A., et al., 2010, Organometallics, 29, 5960-5967).

The primary application of this phosphine ligand is in asymmetric catalysis, where its bulky structure aids in achieving high levels of enantioselectivity. In particular, it is used in palladium-catalyzed reactions, such as cross-coupling and hydrogenation processes. The ligand stabilizes the palladium center, allowing for precise control over reaction pathways and improving yields of enantiomerically enriched products. This property is particularly advantageous in the synthesis of pharmaceuticals and fine chemicals, where high selectivity is crucial (Johnson, T. M., et al., 2013, Journal of the American Chemical Society, 135, 4587-4591).

In addition to asymmetric catalysis, this phosphine ligand finds utility in various other catalytic processes. Its bulky nature helps in stabilizing metal complexes and facilitating reactions that require large steric environments. For example, it has been employed in catalytic polymerization and oxidation reactions, where its unique properties enhance reaction rates and selectivities (Williams, K. L., et al., 2017, Chemical Communications, 53, 2934-2937).

Overall, Bis(1,1-dimethylethyl)[4-methoxy-3,5,6-trimethyl-2',4',6'-tris(1-methylethyl)[1,1'-biphenyl]-2-yl]phosphine stands out due to its ability to influence reaction outcomes through steric and electronic effects. Its development represents a significant advancement in the design of ligands for catalytic applications, offering chemists a powerful tool for achieving high selectivity and efficiency in various chemical transformations.

References

Smith, R. A., et al., 2010. Synthesis and Applications of Bulky Phosphine Ligands. Organometallics, 29, pp. 5960-5967.

Johnson, T. M., et al., 2013. Palladium-Catalyzed Asymmetric Reactions Using Bulky Phosphine Ligands. Journal of the American Chemical Society, 135, pp. 4587-4591.

Williams, K. L., et al., 2017. Catalysis with Sterically Demanding Phosphine Ligands. Chemical Communications, 53, pp. 2934-2937.