Dichloro[(R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl]ruthenium (II)
[CAS# 134524-84-8]

Identification

• Classification: Chemical reagent >> Organic reagent >> Polycyclic compound
• Name: Dichloro[(R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl]ruthenium (II)
• Synonyms: (R)-BINAP dichlororuthenium complex
• Molecular Formula: C₄₄H₃₂Cl₂P₂Ru
• Molecular Weight: 794.65
• CAS Registry Number: 134524-84-8
• EC Number: 634-379-4
• 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.Cl[Ru]Cl

Properties

• Melting point: >300 °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
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319

Discovery and Applications

Dichloro[(R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl]ruthenium(II), commonly known as (R)-BINAP-ruthenium(II) dichloride, is a chiral organometallic complex widely used in asymmetric catalysis. The complex consists of a ruthenium(II) center coordinated to the (R)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl ligand, which imparts chirality to the complex. The (R)-BINAP ligand is a key element in the catalysis, as it provides a rigid, sterically bulky structure, making it a powerful tool for inducing stereoselectivity in various chemical reactions.

The BINAP (bisphosphine-biphenyl) ligand was first introduced in the 1980s and quickly became a foundational component in chiral catalysis. The (R)-enantiomer of BINAP has been particularly significant, and its use in ruthenium complexes has led to substantial advancements in the field of asymmetric synthesis. The (R)-configuration of BINAP in this particular complex is essential for achieving high levels of enantioselectivity in catalytic processes.

This ruthenium complex plays an essential role in various types of asymmetric catalysis, particularly in asymmetric hydrogenation and other transformations that require the generation of chiral centers with high stereocontrol. In asymmetric hydrogenation reactions, (R)-BINAP-ruthenium(II) dichloride is known to catalyze the selective hydrogenation of alkenes or imines, providing the corresponding chiral products with excellent enantiomeric excess. These reactions are crucial for producing chiral intermediates used in the synthesis of pharmaceuticals, agrochemicals, and other fine chemicals, where the enantiomeric purity of the final product is often a key factor.

The (R)-BINAP-ruthenium(II) complex has also been widely applied in asymmetric transfer hydrogenation reactions. In these processes, the complex catalyzes the hydrogenation of carbonyl compounds to chiral alcohols, again with high enantioselectivity. This method provides an efficient and cost-effective route to chiral alcohols, which are important building blocks in the synthesis of various complex molecules. The ability to perform transfer hydrogenation under mild conditions makes this complex particularly valuable for synthetic chemists working with sensitive substrates.

In addition to hydrogenation and transfer hydrogenation, dichloro[(R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl]ruthenium(II) is also used in other catalytic processes that require the generation of chiral centers. The ruthenium center facilitates the activation of substrates, and the (R)-BINAP ligand controls the stereochemistry of the reaction. For example, it has been employed in the asymmetric addition of nucleophiles to electrophilic compounds, in which the ruthenium complex helps guide the nucleophile to the correct face of the substrate, yielding chiral products.

The stability, reactivity, and high stereoselectivity of dichloro[(R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl]ruthenium(II) make it a versatile catalyst in both academic research and industrial applications. Its use has greatly contributed to the efficiency and precision of asymmetric synthesis, allowing the production of complex chiral molecules with high enantiomeric purity. This capability is especially important in the pharmaceutical industry, where even slight variations in the enantiomeric composition of a compound can lead to significant differences in its biological activity.

In summary, dichloro[(R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl]ruthenium(II) is an important catalyst in modern synthetic chemistry, especially in the field of asymmetric catalysis. Its development and application have revolutionized the way chiral molecules are synthesized, making it an indispensable tool in the production of enantiomerically pure compounds. Through its involvement in hydrogenation, transfer hydrogenation, and other catalytic reactions, this ruthenium complex continues to play a crucial role in both research and industrial settings.

References

1991. [2,2′-Dimethyl-6,6′-bis(diphenylphosphino)biphenyl](triphenylphosphine)-dichlororuthenium(II): an enantioselective catalyst for the hydrogenation of diketones. Journal of the Chemical Society, Chemical Communications, (24).
DOI: 10.1039/C39910001675

2022. Aggregation-induced polarization (AIP) of derivatives of BINOL and BINAP. RSC Advances, 12(46).
DOI: 10.1039/D2RA05597J