1,3-Bis(diphenylphosphino)propane

1,3-Bis(diphenylphosphino)propane (dppp) is an organophosphorus compound with the formula Ph₂P(CH₂)₃PPh₂. The compound is a white solid that is soluble in organic solvents. It is slightly air-sensitive, degrading in air to the phosphine oxide. It is classified as a diphosphine ligand in coordination chemistry and homogeneous catalysis.

1,3-Bis(diphenylphosphino)propane

Names
IUPAC name Propane-1,3-diylbis(diphenylphosphane)
Identifiers
CAS Number	6737-42-4^Y
3D model (JSmol)	Interactive image Interactive image
Abbreviations	DPPP
ChEMBL	ChEMBL73394^Y
ChemSpider	73276^Y
ECHA InfoCard	100.027.084
PubChem CID	81219
UNII	44R56E2C68^Y
CompTox Dashboard (EPA)	DTXSID0064464
InChI InChI=1S/C27H26P2/c1-5-14-24(15-6-1)28(25-16-7-2-8-17-25)22-13-23-29(26-18-9-3-10-19-26)27-20-11-4-12-21-27/h1-12,14-21H,13,22-23H2^Y Key: LVEYOSJUKRVCCF-UHFFFAOYSA-N^Y InChI=1/C27H26P2/c1-5-14-24(15-6-1)28(25-16-7-2-8-17-25)22-13-23-29(26-18-9-3-10-19-26)27-20-11-4-12-21-27/h1-12,14-21H,13,22-23H2 Key: LVEYOSJUKRVCCF-UHFFFAOYAP
SMILES P(c1ccccc1)(c2ccccc2)CCCP(c3ccccc3)c4ccccc4 c1ccc(cc1)P(CCCP(c2ccccc2)c3ccccc3)c4ccccc4
Properties
Chemical formula	C27H26P2
Molar mass	412.453 g·mol^−1
Appearance	white solid
Solubility in water	chlorocarbons
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

The diphosphine can be prepared by the reaction of lithium diphenylphosphide and 1,3-dichloropropane (Ph = C₆H₅):

2 Ph₂PLi + C₃H₆Cl₂ → Ph₂P(CH₂)₃PPh₂ + 2 LiCl

However, it can be synthesised via a much more controllable (and cheaper) route, via metal-halogen exchange and then metathesis:

Br(CH₂)₃Br + 2 ^tBuLi → Li(CH₂)₃Li + 2 ^tBuBr

Li(CH₂)₃Li + 2 PCl₃ → Cl₂P(CH₂)₃PCl₂ + 2 LiCl

Cl₂P(CH₂)₃PCl₂ + 4 PhLi → Ph₂P(CH₂)₃PPh₂ + 4 LiCl

Coordination chemistry and use as co-catalyst

The diphosphine serves as a bidentate ligand forming six-membered C₃P₂M chelate ring with a natural bite angle of 91°.[1] For example, the complex dichloro(1,3-bis(diphenylphosphino)propane)nickel is prepared by combining equimolar portions of the ligand and nickel(II) chloride hexahydrate. This nickel complex serves as a catalyst for the Kumada coupling reaction.[2] Dppp is also used as a ligand for palladium(II) catalysts to co-polymerize carbon monoxide and ethylene to give polyketones.[3] Dppp can sometimes be used in palladium-catalyzed arylation under Heck reaction conditions to control regioselectivity.[4]

References

1. Birkholz (née Gensow), Mandy-Nicole; Freixa, Zoraida; van Leeuwen, Piet W. N. M. (2009). "Bite angle effects of diphosphines in C–C and C–X bond forming cross coupling reactions". Chemical Society Reviews. 38 (4): 1099. doi:10.1039/B806211K. PMID 19421583.
2. Kumada, Makota; Tamao, Kohei; Sumitani, Koji (1988). "Phosphine-Nickel Complex Catalyzed Cross-Coupling of Grignard Reagents with Aryl and Alkenyl Halides: 1,2-dibutylbenzene". Organic Syntheses.; Collective Volume, 6, p. 407
3. Drent, E.; Mul, W. P.; Smaardijk, A. A. (2001). "Polyketones". Encyclopedia Of Polymer Science and Technology. doi:10.1002/0471440264.pst273.
4. Cabri, Walter; Candiani, Ilaria; Bedeschi Angelo; Penco, Sergio"α-Regioselectivity in Palladium-Catalyzed Arylation of Acyclic Enol Ethers" journal= Journal of Organic Chemistry, 1991, volume 57, p. 1481. doi:10.1021/jo00031a029