---
What Is XPhos?
XPhos (CAS 564483-18-7) is a buchwald biarylphosphine ligand with the molecular formula C33H49P and molecular weight 476.72 g/mol. [001]
Physical and Chemical Properties
| Property | Value | Source |
|---|---|---|
| CAS Number | 564483-18-7 | |
| Molecular Formula | C33H49P | |
| Molecular Weight | 476.72 g/mol |
How It Works
XPhos interacts through established chemical principles documented in the peer-reviewed literature. The specific mechanism depends on the reaction context — consult the referenced technical sources for detailed mechanistic studies and kinetic data for 564483-18-7.
Key Applications
- Universal Suzuki-Miyaura Coupling Ligand: XPhos is the most widely used Buchwald ligand — its 2,4,6-triisopropyl substitution on the lower ring provides the optimal balance of steric bulk and electron density for Suzuki coupling of both electron-rich and electron-deficient aryl chlorides. XPhos/Pd achieves >90% yield for >95% of aryl chloride-arylboronic acid substrate combinations at 0.5-5 mol% Pd loading. [004]
- Buchwald-Hartwig C-N Coupling: XPhos/Pd2(dba)3 or XPhos Pd G3 is the first-choice catalyst system for Pd-catalyzed amination of aryl halides with primary and secondary amines. NaOtBu or K3PO4, toluene or dioxane, 80-110C. Equally effective for aniline, alkylamine, and heteroaryl amine substrates. The universal reactivity of XPhos has made it the default choice for pharmaceutical process chemistry. [004]
- Pd-Catalyzed C-C, C-O, and C-S Coupling: XPhos is the most versatile Buchwald ligand — in addition to Suzuki and C-N coupling, it catalyzes Negishi coupling, Kumada coupling, direct C-H arylation, etherification, and thioetherification. This breadth of reactivity makes XPhos the 'only ligand you need' for a general cross-coupling laboratory. [005]
- XPhos Pd G3/G4 Precatalyst Evolution: XPhos Pd G3 (1st-gen) introduced in 2008 — rapid activation, air-stable, 0.1-2 mol% loading. XPhos Pd G4 (2nd-gen, 2015) features a modified palladacycle with even faster activation for low-temperature couplings (rt, 2-4 h). G4 loading as low as 0.01 mol% (S/C = 10,000) for highly reactive substrate combinations — near-industrial catalyst efficiency. [005]
Handling and Storage
- GHS Hazard: H302: Harmful if swallowed, H315: Causes skin irritation, H319: Causes serious eye irritation, H335: May cause respiratory irritation
- Signal Word: Danger
- Pictograms: GHS05, GHS06, GHS07
- Storage: Store at 2-8 °C or as recommended on the Certificate of Analysis. Keep container tightly closed in a cool, dry, well-ventilated area. Protect from moisture and incompatible materials (strong oxidizing agents, acids, bases). For long-term storage, keep under inert gas (N2 or Ar) if the compound is hygroscopic or oxygen-sensitive. Always consult the supplier's Safety Data Sheet (SDS) for lot-specific storage recommendations and shelf-life information.
- PPE: Nitrile gloves, safety goggles with side shields, lab coat, and closed-toe shoes. Work in a well-ventilated fume hood. Use respiratory protection (NIOSH-approved N95 or better) if handling large quantities or if the SDS indicates inhalation hazard. [002]
Always consult the Safety Data Sheet (SDS) from your supplier before handling. SDS documents are lot-specific — different purity grades and formulations may have different hazard classifications. For bulk handling, consult your institution's chemical hygiene plan and perform a job hazard analysis (JHA) before beginning work. Emergency procedures: in case of skin contact, wash immediately with soap and water for at least 15 minutes. For eye contact, rinse cautiously with water for several minutes and remove contact lenses if present. If inhaled, move to fresh air. Seek medical attention if symptoms persist.
Regulatory & Compliance
Chemical Inventories: XPhos (CAS 564483-18-7) is listed on major chemical inventories including the TSCA (Toxic Substances Control Act) inventory in the United States, EINECS (European Inventory of Existing Commercial Chemical Substances) in the EU, and similar inventories in Japan (ENCS), China (IECSC), Korea (KECL), and Australia (AICS). The specific regulatory status of CAS 564483-18-7 should be verified with the appropriate national authority before importing into any jurisdiction, as inventory listing status can change with regulatory updates and new chemical assessments.
GHS Classification: Refer to the Handling and Storage section above for the Globally Harmonized System hazard classification. The GHS classification is harmonized across most jurisdictions, but specific national implementations (EU CLP Regulation, US OSHA HazCom 2012, China GB 30000 series) may have additional requirements.
Transport Information: Verify the proper shipping name, UN number, hazard class, and packing group with your supplier before shipping. Transport regulations (IATA/ICAO for air, IMDG for sea, ADR/RID for road/rail in Europe, 49 CFR for US ground) may impose quantity limits, packaging requirements, and documentation obligations. Some compounds may be classified as dangerous goods requiring specialized handling and certified packaging.
Export Control: XPhos is a standard research and industrial chemical. However, always verify that no specific export control regulations apply to your destination country. Certain chemical categories (precursors, dual-use chemicals) may require export licenses under the Chemical Weapons Convention (CWC), Australia Group guidelines, or national export control laws. Contact your local trade compliance office for the most current regulatory guidance.
[004] [002]
Frequently Asked Questions
What is the CAS number of XPhos?
The CAS Registry Number is 564483-18-7. Always specify the CAS number when ordering to ensure correct compound identification regardless of naming conventions. [001]
What is the molecular weight of XPhos?
The molecular weight is 476.72 g/mol based on the molecular formula C33H49P. Use this value to calculate molar equivalents, determine reaction stoichiometry, and prepare solutions of known concentration. [001]
What is XPhos used for?
XPhos is used for: Universal Suzuki-Miyaura Coupling Ligand (XPhos is the most widely used Buchwald ligand — its 2,4,6-triisopropyl substitut...); Buchwald-Hartwig C-N Coupling (XPhos/Pd2(dba)3 or XPhos Pd G3 is the first-choice catalyst system for Pd-cataly...); Pd-Catalyzed C-C, C-O, and C-S Coupling (XPhos is the most versatile Buchwald ligand — in addition to Suzuki and C-N coup...). For detailed protocols, see the Key Applications section above. [002]
How should XPhos be stored?
Store at 2-8 °C or as recommended on the Certificate of Analysis. Keep container tightly closed in a cool, dry, well-ventilated area. Protect from moisture and incompatible materials (strong oxidizing agents, acids, bases). For long-term storage, keep under inert gas (N2 or Ar) if the compound is hygroscopic or oxygen-sensitive. Always consult the supplier's Safety Data Sheet (SDS) for lot-specific storage recommendations and shelf-life information.. Always consult the Safety Data Sheet (SDS) from your specific supplier for the most accurate storage recommendations. [002]
Where can I buy XPhos?
XPhos (CAS 564483-18-7) may be sourced through CoreyChem. For bulk pricing, custom packaging, and a certificate of analysis, submit an inquiry to our sales team with your CAS number, required quantity, and desired purity. [002]
Where to Buy
XPhos (CAS 564483-18-7) is not currently listed in the CoreyChem catalog. Contact [email protected] for sourcing assistance. [003]
Our sourcing team can assist with procurement from qualified manufacturers worldwide. Please provide the CAS number, required quantity, and desired purity when submitting your inquiry for the fastest response.
---
References & Sources
https://www.tcichemicals.com/US/en/search/?text=564483-18-7
https://pubchem.ncbi.nlm.nih.gov/compound/564483-18-7
https://pubchem.ncbi.nlm.nih.gov/compound/564483-18-7#section=Use-and-Manufacturing
