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CYTOP® 340 – A Versatile Reagent

Utilized in the fine chemical industry

Tributylphosphine finds utility in many organic transformations that are widely utilized in the fine chemical industry, such as Staudinger(1), Morita-Baylis-Hillman(2), Wittig(3), Michael addition(4) and Mitsunobu.(5)In polyurethane manufacture it is commonly used as a catalyst for the formation of oligomeric isocyanates.(6) In addition it has broad application as a ligand for homogeneous catalysis and in the manufacture of phosphonium salts.(7)

Utility in Azide Reductions


In this article we focus on one particular transformation, the Staudinger Reaction: a mild method of reducing an azide to an amine first reported in 1919.(8) The two most common reducing agents used in this reaction are triphenylphosphine and tri-n-butylphosphine.  CYTOP® 340 (Strem Catalog: 97-5801) has a number of advantages over triphenylphosphine as documented in the table below.


Examples  of reactivity for the two reducing agents, are shown below.(9)


These advantages led to CYTOP® 340 (Strem Catalog: 97-5801) being chosen as the reducing agent for the industrial manufacturing of oseltamivir phosphate (Tamiflu®).(1)


CYTOP® 340 (Strem Catalog: 97-5801) is a commercial scale tertiary phosphine finding increased use in applications where its form, a readily dispensed mobile liquid, and low vapor pressure are of benefit. To learn more about other specialty phosphorus products, please refer to the Solvay offering at Strem or the Solvay website.



  1.  US 6,462,226 Oct. 8, 2002.
  2.  J. Am. Chem. Soc., 2011, 133, 13337-13348.
  3.  Phosphorus, Sulfur, and Silicon and the Related Elements, 2015, 190, 619-632.
  4.  Tetrahedron Letters 2002, 43, 8707-8710.
  5.  Chem. Lett. 2005, 15, 5315-5318.
  6.  Angew. Chem. Int. Ed. 2006, 45, 107-110.
  7.  Synthesis 2003, 317-334.
  8.  Helv. Chima. Acta 1919, 2, 635-646.
  9.  Solvay unpublished results.


Featured Product:

97-5801 Tri-n-butylphosphine, min. 93% [CYTOP® 340 ORGANOPHOSPHINE] (998-40-3)


Related Products:

All products sold in collaboration with Solvay
CYTOP Products
Phosphorus Ligands and Compounds Booklet



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