(R)-(+)-2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl
[CAS# 76189-55-4]

Identification

• Classification: Chemical reagent >> Organic reagent >> Phosphine ligand
• Name: (R)-(+)-2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl
• Synonyms: (R)-(+)-BINAP; (R)-BINAP; R-BINAP
• Molecular Formula: C₄₄H₃₂P₂
• Molecular Weight: 622.68
• CAS Registry Number: 76189-55-4
• EC Number: 616-304-7
• SMILES: C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=C(C4=CC=CC=C4C=C3)C5=C(C=CC6=CC=CC=C65)P(C7=CC=CC=C7)C8=CC=CC=C8

Properties

• Melting point: 239-242 °C
• alpha: 240 ° (c=0.3, toluene)
• Water solubility: insoluble

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Risk Statements: H315-H319-H335-H410-H413
• Safety Statements: P261-P264-P264+P265-P271-P273-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P391-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413

Discovery and Applications

(R)-(+)-2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl, commonly known as (R)-BINAP, is a chiral phosphine ligand that has played a pivotal role in the field of asymmetric catalysis. The ligand’s unique structure and properties have made it an essential tool in numerous chemical transformations, particularly those requiring high stereochemical control.

The discovery of (R)-BINAP dates back to the 1980s when researchers were exploring new ligands for asymmetric catalysis. Its synthesis involves the reaction of 2,2'-dihydroxy-1,1'-binaphthyl with diphenylphosphine in the presence of a suitable acid catalyst to form the bis(phosphine) derivative. The resulting ligand features two diphenylphosphine groups attached to a chiral binaphthyl backbone. This configuration provides a rigid and well-defined chiral environment around the phosphorus atoms, which is crucial for its effectiveness in asymmetric reactions.

One of the most significant applications of (R)-BINAP is in asymmetric hydrogenation, a reaction in which hydrogen is added to an unsaturated substrate to produce a chiral product. In the presence of (R)-BINAP, metal catalysts, typically based on rhodium or ruthenium, achieve high enantioselectivity, making it possible to produce optically active compounds with high precision. This application has broad implications in the synthesis of pharmaceuticals and other fine chemicals where enantiomerically pure products are required.

Another notable application of (R)-BINAP is in asymmetric Suzuki-Miyaura cross-coupling reactions. This reaction involves the coupling of an aryl or vinyl boronic acid with an aryl or vinyl halide to form a biaryl or vinyl compound. The use of (R)-BINAP as a ligand in palladium-catalyzed Suzuki-Miyaura reactions enhances the selectivity and efficiency of the process, enabling the synthesis of complex organic molecules with high chirality. This has been particularly useful in the development of biologically active compounds and advanced materials.

In addition to its role in hydrogenation and cross-coupling reactions, (R)-BINAP is also employed in various other asymmetric transformations, including the asymmetric transfer hydrogenation and the asymmetric hydroamination of alkenes. These applications highlight the versatility of (R)-BINAP in enabling a wide range of chiral synthesis methodologies.

The effectiveness of (R)-BINAP is attributed to its rigid, chiral structure, which provides a well-defined coordination environment for transition metal centers. The high selectivity achieved in asymmetric reactions is a direct result of the ligand's ability to create a consistent and controlled chiral environment, which influences the reactivity and selectivity of the metal catalyst.

Overall, (R)-(+)-2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl has become a cornerstone in asymmetric catalysis, contributing significantly to the development of enantioselective synthetic methodologies. Its discovery and application have had a profound impact on the field, facilitating the production of chiral compounds across various domains of chemical synthesis.

References

2024. Rh-catalysed enantioselective [2+2+1] cycloaddition reactions using three different 2π-components. Nature Synthesis, 3(7).
DOI: 10.1038/s44160-024-00604-7

2024. Catalytic atroposelective synthesis. Nature Catalysis, 7(4).
DOI: 10.1038/s41929-024-01138-z

1991. Asymmetric Hydrogenation. Metal Promoted Selectivity in Organic Synthesis.
DOI: 10.1007/978-94-011-3408-8_8