Diphenylphosphine oxide

Diphenylphosphine oxide
Names
	Preferred IUPAC name Diphenyl-λ5-phosphanone
Identifiers
CAS Number	4559-70-0 ;
3D model (JSmol)	Interactive image;
ChemSpider	222625;
PubChem CID	254003;
UNII	XXW49HG6X3 ;
	InChI InChI=1S/C12H11OP/c13-14(11-7-3-1-4-8-11)12-9-5-2-6-10-12/h1-10,14H Key: ASUOLLHGALPRFK-UHFFFAOYSA-N;
	SMILES c1ccc(cc1)P(=O)c2ccccc2;
Properties
Chemical formula	C12H11OP
Molar mass	202.19
Appearance	white solid
Melting point	56-57 °C
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Diphenylphosphine oxide is an organophosphorus compound with the formula (C₆H₅)₂P(O)H. It is a white solid that soluble in polar organic solvents.^[1]

Synthesis

Diphenylphosphine oxide can be prepared by the reaction of phosphonic esters, such as diethylphosphite, with Grignard reagents followed by acid workup:^[2]

(C₂H₅O)₂P(O)H + 3 C₆H₅MgBr → (C₆H₅)₂P(O)MgBr + C₂H₅OMgBr

(C₆H₅)₂P(O)MgBr + HCl → (C₆H₅)₂P(O)H + MgBrCl

Alternatively, it may be prepared by the partial hydrolysis of chlorodiphenylphosphine^[1] or diphenylphosphine.^[3]

Reactions

Diphenylphosphine oxide exists in equilibrium with its minor tautomer diphenylphosphinous acid, ((C₆H₅)₂POH:

(C₆H₅)₂P(O)H ⇌ (C₆H₅)₂POH

Diphenylphosphine oxide is used in Buchwald-Hartwig coupling reactions to introduce diphenylphosphino substituents.^[1]

Thionyl chloride converts diphenylphosphine oxide to chlorodiphenylphosphine.

Organophosphinous acids are deoxygenated with DIBAH. The resulting secondary phosphines are precursors to phosphine ligands.^[4]

References

^ ^a ^b ^c Saunders, Jeffrey O.; Wang, Zheng; Ding, Kuiling (2007). "Diphenylphosphine Oxide". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rd428.pub2. ISBN 978-0-471-93623-7.
^ Hunt, B. B.; Saunders, B. C. (1957). "Preparation and Reactions of Diphenylphosphine Oxide". J. Chem. Soc.: 2413–2414. doi:10.1039/JR9570002413.
^ Rauhut, M. M.; Currier, Helen A. (November 1961). "Oxidation of Secondary Phosphines to Secondary Phosphine Oxides". The Journal of Organic Chemistry. 26 (11): 4626–4628. doi:10.1021/jo01069a102.
^ Carl A. Busacca; Jon C. Lorenz; Paul Sabila; Nizar Haddad; Chris H. Senanyake (2007). "Synthesis Of Electron-Deficient Secondary Phosphine Oxides And Secondary Phosphines: Bis[3,5-bis(Trifluoromethyl)phenyl]phosphine Oxide And Bis[3,5-bis(Trifluoromethyl)phenyl]phosphine". Org. Synth. 84: 242. doi:10.15227/orgsyn.084.0242.

[e-EROS-1] Saunders, Jeffrey O.; Wang, Zheng; Ding, Kuiling (2007). "Diphenylphosphine Oxide". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rd428.pub2. ISBN 978-0-471-93623-7.

[2] Hunt, B. B.; Saunders, B. C. (1957). "Preparation and Reactions of Diphenylphosphine Oxide". J. Chem. Soc.: 2413–2414. doi:10.1039/JR9570002413.

[3] Rauhut, M. M.; Currier, Helen A. (November 1961). "Oxidation of Secondary Phosphines to Secondary Phosphine Oxides". The Journal of Organic Chemistry. 26 (11): 4626–4628. doi:10.1021/jo01069a102.

[4] Carl A. Busacca; Jon C. Lorenz; Paul Sabila; Nizar Haddad; Chris H. Senanyake (2007). "Synthesis Of Electron-Deficient Secondary Phosphine Oxides And Secondary Phosphines: Bis[3,5-bis(Trifluoromethyl)phenyl]phosphine Oxide And Bis[3,5-bis(Trifluoromethyl)phenyl]phosphine". Org. Synth. 84: 242. doi:10.15227/orgsyn.084.0242.

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