5-[Di(tert-butyl)phosphino]-1',3',5'-triphenyl-1'H-[1,4']bipyrazolyl
[CAS# 894086-00-1]

Identification

• Name: 5-[Di(tert-butyl)phosphino]-1',3',5'-triphenyl-1'H-[1,4']bipyrazolyl
• Synonyms: ditert-butyl-[2-(1,3,5-triphenylpyrazol-4-yl)pyrazol-3-yl]phosphane
• Molecular Formula: C₃₂H₃₅N₄P
• Molecular Weight: 506.62
• CAS Registry Number: 894086-00-1
• EC Number: 814-047-7
• SMILES: CC(C)(C)P(C1=CC=NN1C2=C(N(N=C2C3=CC=CC=C3)C4=CC=CC=C4)C5=CC=CC=C5)C(C)(C)C

Properties

• Solubility: Insoluble (1.9E^-5 g/L) (25 °C), Calc.^*
• Melting point: 191-193 °C^**

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software V11.02 (©1994-2013 ACD/Labs)

^** Withbroe, Gregory J.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H315-H319-H335
• Safety Statements: P261-P305+P351+P338

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

5-[Di(tert-butyl)phosphino]-1',3',5'-triphenyl-1'H-[1,4']bipyrazolyl is a sophisticated organophosphorus compound notable for its applications in catalysis and materials science. This molecule, with its intricate structure, incorporates both phosphorus-containing ligands and a bipyrazolyl framework, which endow it with unique properties beneficial for various chemical processes.

The discovery of 5-[Di(tert-butyl)phosphino]-1',3',5'-triphenyl-1'H-[1,4']bipyrazolyl involved the development of novel ligands for transition metal catalysis. Researchers aimed to design a ligand with high steric and electronic properties to enhance the efficiency and selectivity of catalytic reactions. The synthesis of this compound begins with the preparation of a bipyrazolyl core, which is then functionalized with di(tert-butyl)phosphine groups. The di(tert-butyl)phosphine moieties are introduced through a phosphination reaction, where the phosphorus center is attached to the pyrazolyl rings, creating a ligand with significant steric bulk and electronic influence.

The primary application of 5-[Di(tert-butyl)phosphino]-1',3',5'-triphenyl-1'H-[1,4']bipyrazolyl is as a ligand in transition metal catalysis. Its bulky di(tert-butyl)phosphine groups provide strong coordination to metal centers, enhancing the stability of metal-ligand complexes. This stabilization is crucial in catalytic cycles, particularly in reactions such as cross-coupling processes, where the ligand facilitates the formation of carbon-carbon bonds. The bipyrazolyl structure contributes to the ligand's ability to control the geometry and electronic environment around the metal center, leading to improved catalytic performance.

Additionally, this compound is utilized in asymmetric catalysis, where it serves as a chiral ligand. The chiral environment created by the bipyrazolyl framework allows for the selective formation of enantiomerically pure products. This application is particularly valuable in the synthesis of pharmaceuticals and fine chemicals, where high selectivity and control over stereochemistry are essential.

Beyond catalysis, 5-[Di(tert-butyl)phosphino]-1',3',5'-triphenyl-1'H-[1,4']bipyrazolyl has potential applications in materials science. The ability of this ligand to coordinate to transition metals allows for the creation of functional materials with specific electronic and optical properties. These materials can be employed in various high-tech applications, including sensors, displays, and advanced electronic devices.

In summary, 5-[Di(tert-butyl)phosphino]-1',3',5'-triphenyl-1'H-[1,4']bipyrazolyl is a versatile compound with significant roles in transition metal catalysis, asymmetric synthesis, and materials science. Its unique structure provides valuable properties that enhance the efficiency and selectivity of chemical reactions, as well as contribute to the development of advanced materials.

References

2013. BippyPhos: A Single Ligand With Unprecedented Scope in the Buchwald-Hartwig Amination of (Hetero)aryl Chlorides. Chemistry (Weinheim an der Bergstrasse, Germany), 19(45).
DOI: 10.1002/chem.201302453