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
Preferred IUPAC name (Propane-1,3-diyl)bis(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). Y verify (what is YN ?) Infobox references

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

2 Ph₂PLi + Cl(CH₂)₃Cl → 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]