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.

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°. 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. Dppp is also used as a ligand for palladium(II) catalysts to co-polymerize carbon monoxide and ethylene to give polyketones. Dppp can sometimes be used in palladium-catalyzed arylation under Heck reaction conditions to control regioselectivity.