[(4R)-[4,4'-Bi-1,3-benzodioxole]-5,5'-diyl]bis[diphenylphosphine]
[CAS# 244261-66-3]

Identification

• Classification: Organic raw materials >> Organic phosphine compound
• Name: [(4R)-[4,4'-Bi-1,3-benzodioxole]-5,5'-diyl]bis[diphenylphosphine]
• Synonyms: (R)-(+)-Segphos; (R)-Segphos
• Molecular Formula: C₃₈H₂₈O₄P₂
• Molecular Weight: 610.59
• CAS Registry Number: 244261-66-3
• EC Number: 812-649-4
• SMILES: C1OC2=C(O1)C(=C(C=C2)P(C3=CC=CC=C3)C4=CC=CC=C4)C5=C(C=CC6=C5OCO6)P(C7=CC=CC=C7)C8=CC=CC=C8

Properties

• Melting point: 168-172 °C (Expl.)
• Boiling Point: 715.4±60.0 °C (760 mmHg), Calc.^*
• Flash Point: 488.8±33.2 °C, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

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

Discovery and Applications

(R)-(+)-Segphos is a chiral diphosphine ligand that has significantly impacted the field of asymmetric catalysis. Known for its high enantioselectivity, it plays a critical role in promoting reactions where the stereochemistry of the product is essential. The ligand is derived from a binaphthyl backbone and contains two phosphorus atoms, providing a rigid structure that facilitates precise control over the configuration of the reaction. This makes (R)-(+)-Segphos particularly valuable in the synthesis of optically active compounds, which are crucial for applications in the pharmaceutical and agrochemical industries.

The discovery of (R)-(+)-Segphos can be traced to ongoing research efforts in the late 20th century focused on improving chiral ligands for transition metal catalysis. Researchers sought ligands that could enhance the performance of metal-catalyzed reactions, particularly for the creation of stereochemically pure molecules. (R)-(+)-Segphos was developed as part of this initiative, with its specific chiral configuration optimized to achieve higher selectivity in catalytic processes. Its unique structural features set it apart from other diphosphine ligands, contributing to its broad adoption in various catalytic applications.

The synthesis of (R)-(+)-Segphos typically begins with the preparation of a chiral binaphthyl derivative, followed by the introduction of two phosphine groups. The synthetic approach ensures the preservation of the desired stereochemistry, which is crucial for the ligand's effectiveness. This method allows for the production of (R)-(+)-Segphos in high purity and with excellent enantiomeric excess, ensuring its performance in demanding catalytic applications. The ligand's ability to undergo various modifications further enhances its versatility, enabling it to be tailored for different catalytic reactions.

In terms of application, (R)-(+)-Segphos is widely used in asymmetric hydrogenation reactions. When coordinated with metals like rhodium or ruthenium, the ligand forms highly efficient catalysts that can convert prochiral substrates into enantiomerically pure products. This has been particularly useful in the synthesis of complex pharmaceuticals, including antibiotics and anti-cancer agents. Additionally, (R)-(+)-Segphos is employed in asymmetric cross-coupling reactions, such as the Suzuki and Heck reactions, which are essential for the construction of carbon-carbon bonds in organic synthesis. Its ability to improve both the yield and enantioselectivity of these reactions makes it a valuable tool for synthetic chemists.

The impact of (R)-(+)-Segphos extends beyond the laboratory, as it has been successfully adopted in industrial processes where the production of chiral molecules is necessary. Its robustness under various reaction conditions and its ability to generate high-quality enantiomerically enriched products have cemented its place in the toolkit of modern synthetic chemistry.

References

2023. Palladium-catalyzed allylic alkylation enabled by ketone umpolung via Pudovik addition/[1,2]-phospha-Brook rearrangement. *Science China Chemistry*, 66(11).
DOI: 10.1007/s11426-023-1744-2

2023. Catalytic enantioselective synthesis of boron-stereogenic BODIPYs. *Nature Synthesis*, 2(7).
DOI: 10.1038/s44160-023-00262-1

2022. Enantioselective C-H Functionalization toward Silicon-Stereogenic Silanes. *Synthesis*, 54(15).
DOI: 10.1055/a-1729-9664