Diphenylphosphine
From Wikipedia, the free encyclopedia
| Diphenylphosphine | |
|---|---|
 |
 |
| IUPAC name | diphenylphosphane |
| Identifiers | |
| CAS number | [829-85-6] |
| Properties | |
| Molecular formula | C12H11P |
| Molar mass | 186.19 g/mol |
| Appearance | colorless liquid |
| Density | 1.07 g/cm3, liquid |
| Melting point |
65-67 °C (338-340 K) |
| Boiling point |
280 °C (553 K) |
| Solubility in water | Insoluble |
| Hazards | |
| MSDS | External MSDS |
| R-phrases | 17-36/37/38 |
| S-phrases | 26-36 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Diphenylphosphine, also known as diphenylphosphane, is the compound with the formula (C6H5)2PH. This foul smelling, colorless liquid is easily oxidized in air. It is mainly used in the synthesis of organophosphorus ligands for use as catalysts.
[edit] Synthesis
Diphenylphosphine can be synthesized from triphenylphosphine.[1]
- PPh3 + 2Li → LiPPh2 + LiPh
- LiPPh2 + H2O → Ph2PH + LiOH
[edit] Uses
Diphenylphosphine is readily deprotonated to give diphenylphosphide derivatives.[2] The preparation of phosphine ligands, Wittig–Horner reagents, and phosphonium salts is commonly accomplished by alkylating diphenylphosphine. The hydrogen atom connected to phosphorus undergoes Michael-like addition to activated alkenes, providing products with which to produce phosphine ligands such as 1,2-Bis(diphenylphosphino)ethane (Ph2PC2H4PPh2). Diphenylphosphine and especially diphenylphosphide derivatives are nucleophiles, so they add to carbon – heteroatom double bonds.[2] For example, in the presence of concentrated hydrochloric acid at 100 °C), diphenylphosphine adds to the carbon atom in benzaldehyde to give (phenyl-(phenylmethyl)phosphoryl)benzene.
- Ph2PH + PhCHO → Ph2P(O)CH2Ph
During the handling of diphenylphosphine, care must be taken to avoid oxidation of diphenylphosphine.[3]
- Ph2PH + O2 → Ph2P(O)OH
The use of the diphenylphosphine–borane complex, Ph2PH•BH3 avoids the problem of phosphine oxidation by protecting the phosphine from oxidation and is available through chemical vendors.[2]
[edit] References
- ^ Wittenberg, D.; Gilman, H. (1958). "Lithium Cleavages of Triphenyl Derivatives of Some Group Vb Elements in Tetrahydrofuran". J. Org. Chem. 23: 1063-1065. doi:.
- ^ a b c Piotrowski, D. W. “Diphenylphosphine” Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons: New York, 2001. doi:10.1002/047084289X.rd427.
- ^ Svara, J., Weferling, N., Hofmann, T. “Organic Phosphorus Compounds” Ullmann's Encyclopedia of Industrial Chemistry. John Wiley & Sons: New York, 2006. doi:10.1002/14356007.a19_545.pub2 .
