2-[Di(tert-butyl)phosphino]-1,1'-binaphthyl
[CAS# 255836-67-0]

Identification

• Classification: Chemical reagent >> Organic reagent >> Phosphine ligand
• Name: 2-[Di(tert-butyl)phosphino]-1,1'-binaphthyl
• Synonyms: ditert-butyl-(2-phenylphenyl)phosphane
• Molecular Formula: C₂₈H₃₁P
• Molecular Weight: 398.52
• CAS Registry Number: 255836-67-0
• EC Number: 686-973-8
• SMILES: CC(C)(C)P(C1=C(C2=CC=CC=C2C=C1)C3=CC=CC4=CC=CC=C43)C(C)(C)C

Properties

• Melting point: 144-148 °C

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety 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

Discovery and Applications

2-[Di(tert-butyl)phosphino]-1,1'-binaphthyl is a notable chemical compound in the realm of organometallic chemistry, particularly recognized for its role as a ligand in asymmetric catalysis. This compound has gained attention for its ability to enhance the efficiency and selectivity of various catalytic processes, contributing to advancements in synthetic chemistry.

The discovery of 2-[Di(tert-butyl)phosphino]-1,1'-binaphthyl can be traced back to the late 20th century. The compound was developed as part of an effort to create new chiral ligands that could offer improved performance in asymmetric synthesis. The ligand features a binaphthyl backbone with two bulky di(tert-butyl)phosphino groups attached at the 2 position of the naphthyl rings. This structure was designed to provide a high level of steric protection and electronic influence, which can significantly impact the behavior of metal catalysts.

The synthesis of 2-[Di(tert-butyl)phosphino]-1,1'-binaphthyl involves a series of steps. The process begins with the preparation of the binaphthyl framework, which is typically achieved through coupling reactions of naphthalene derivatives. The di(tert-butyl)phosphino groups are then introduced via a reaction with a phosphorus-containing reagent. The resulting compound is purified through techniques such as column chromatography to obtain a high-purity ligand suitable for catalytic applications.

One of the primary applications of 2-[Di(tert-butyl)phosphino]-1,1'-binaphthyl is in asymmetric catalysis. The ligand is employed to create chiral metal complexes that can catalyze a variety of asymmetric reactions, including hydrogenation, hydroformylation, and cross-coupling reactions. The bulky di(tert-butyl) groups provide significant steric hindrance, which helps to stabilize transition states and enhance the selectivity of the reactions.

In asymmetric hydrogenation, 2-[Di(tert-butyl)phosphino]-1,1'-binaphthyl is used to create catalysts that facilitate the reduction of unsaturated compounds with high enantioselectivity. The steric effects of the di(tert-butyl) groups play a crucial role in determining the outcome of the reaction, leading to improved yields and selectivity for the desired enantiomers.

The compound is also used in asymmetric hydroformylation, where it helps in the formation of aldehydes from alkenes. The presence of the di(tert-butyl)phosphino ligand can influence the reaction rate and selectivity, allowing for the production of aldehydes with high precision and minimal by-products.

In cross-coupling reactions, 2-[Di(tert-butyl)phosphino]-1,1'-binaphthyl acts as a ligand that enhances the formation of carbon-carbon bonds. The unique steric and electronic properties imparted by the ligand contribute to higher yields and better selectivity in the synthesis of complex organic molecules.

The advantages of using 2-[Di(tert-butyl)phosphino]-1,1'-binaphthyl include its ability to provide a highly defined steric and electronic environment around the metal center, which can enhance catalytic performance. However, challenges associated with its use may include the need for careful optimization of reaction conditions to achieve the desired results and the potential for ligand deactivation in certain scenarios.

Future research into 2-[Di(tert-butyl)phosphino]-1,1'-binaphthyl may focus on exploring new catalytic applications and optimizing the ligand’s performance in various processes. Researchers may also investigate modifications to the ligand structure to further enhance its properties and develop new derivatives with improved reactivity and selectivity.

References

2022. Synthesis of Danuglipron: An Orally Available GLP-1R Agonist. Synfacts, 18(09).
DOI: 10.1055/s-0041-1738304

2018. Norbornene in Organic Synthesis. Synthesis, 50(24).
DOI: 10.1055/s-0037-1610143

2015. Fluoroalcohol-mediated reductive iodonio-Claisen rearrangement: Synthesis of complex ortho-substituted-allyl iodoarenes. Frontiers of Chemical Science and Engineering, 9(3).
DOI: 10.1007/s11705-015-1530-6