2-Di-tert-butylphosphino-2',4',6'-triisopropylbiphenyl
[CAS# 564483-19-8]

Identification

• Classification: Organic raw materials >> Organic phosphine compound
• Name: 2-Di-tert-butylphosphino-2',4',6'-triisopropylbiphenyl
• Synonyms: Palladium (methanesulfonato-?O)[2'-(methylamino)[1,1'-biphenyl]-2-yl]-, compd. with dicyclohexyl[3-(1-methylethoxy)-2',4',6'-tris(1-methylethyl)[1,1'-biphenyl]-2-yl]phosp
• Molecular Formula: C₂₉H₄₅P
• Molecular Weight: 424.64
• CAS Registry Number: 564483-19-8
• EC Number: 639-817-8
• SMILES: CC(C)c1cc(c(c(c1)C(C)C)c2cccc(c2P(C3CCCCC3)C4CCCCC4)OC(C)C)C(C)C.CNc1ccccc1c2ccccc2[Pd]OS(=O)(=O)C

Properties

• Melting point: 148-151 °C

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H312-H332
• Safety Statements: P261-P264-P270-P271-P280-P301+P317-P302+P352-P304+P340-P317-P321-P330-P362+P364-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	3	H302
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2A	H319
Eye irritation	Eye Irrit.	2	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Skin sensitization	Skin Sens.	1	H317
Reproductive toxicity	Repr.	1A	H360

Discovery and Applications

2-Di-tert-butylphosphino-2',4',6'-triisopropylbiphenyl, commonly abbreviated as 2-Dtbp-2',4',6'-Tipb, is a highly specialized phosphine ligand notable for its role in organometallic chemistry. This compound represents an important development in ligand design, enhancing the efficacy of various catalytic processes.

The discovery of 2-Dtbp-2',4',6'-Tipb was driven by the need for ligands that offer both high steric bulk and electronic tuning, essential for optimizing catalytic reactions. The ligand features a biphenyl backbone substituted with three isopropyl groups and two bulky tert-butyl groups attached to the phosphorus atom. This unique structure provides significant steric hindrance, which is crucial for stabilizing metal centers and modulating their reactivity.

The primary application of 2-Dtbp-2',4',6'-Tipb is in palladium-catalyzed cross-coupling reactions, such as the Suzuki-Miyaura, Heck, and Negishi reactions. These reactions are pivotal in organic synthesis, enabling the formation of carbon-carbon bonds essential for constructing complex molecules. The steric and electronic properties of 2-Dtbp-2',4',6'-Tipb enhance the performance of palladium catalysts by preventing catalyst deactivation and improving reaction selectivity and efficiency.

The ligand’s steric bulk helps in overcoming issues related to substrate sterics, making it particularly useful for reactions involving bulky or hindered substrates. By providing a more favorable environment for the palladium center, 2-Dtbp-2',4',6'-Tipb facilitates higher yields and more precise control over reaction pathways.

In addition to its role in cross-coupling reactions, 2-Dtbp-2',4',6'-Tipb has also been explored in other catalytic processes, including carbonylation and polymerization. Its ability to stabilize palladium complexes and enhance reactivity under various conditions makes it a versatile tool in synthetic chemistry.

The development and application of 2-Dtbp-2',4',6'-Tipb illustrate the advancements in ligand design that contribute to more efficient and selective catalysis. Its unique structural features and the ability to tackle challenging reactions underscore its significance in both academic research and industrial applications.

Overall, 2-Di-tert-butylphosphino-2',4',6'-triisopropylbiphenyl represents a valuable addition to the toolkit of chemists working with palladium catalysis. Its impact on reaction efficiency and selectivity highlights the ongoing importance of designing ligands with tailored properties to meet the demands of complex chemical synthesis.

References

2023. Exciting catalysts for borylation and benzene synthesis. Nature Synthesis, 2(5).
DOI: 10.1038/s44160-023-00288-5

2020. Recent Advances of 1,3,5-Triazinanes in Aminomethylation and Cycloaddition Reactions. Synthesis, 52(15).
DOI: 10.1055/s-0040-1707160

2014. Making C-C Bonds from Carbon Dioxide via Transition-Metal Catalysis. Topics in Catalysis, 57(17-20).
DOI: 10.1007/s11244-014-0301-9