Английская Википедия:1,3-Bis(diphenylphosphino)propane
1,3-Bis(diphenylphosphino)propane (dppp) is an organophosphorus compound with the formula PhШаблон:SubP(CHШаблон:Sub)Шаблон:SubPPhШаблон:Sub. 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 = CШаблон:SubHШаблон:Sub):
- 2 PhШаблон:SubPLi + Cl(CHШаблон:Sub)Шаблон:SubCl → PhШаблон:SubP(CHШаблон:Sub)Шаблон:SubPPhШаблон:Sub + 2 LiCl
However, it can be synthesised via a much more controllable (and cheaper) route, via metal-halogen exchange and then metathesis:
- Br(CHШаблон:Sub)Шаблон:SubBr + 2 Шаблон:SupBuLi → Li(CHШаблон:Sub)Шаблон:SubLi + 2 Шаблон:SupBuBr
- Li(CHШаблон:Sub)Шаблон:SubLi + 2 PClШаблон:Sub → ClШаблон:SubP(CHШаблон:Sub)Шаблон:SubPClШаблон:Sub + 2 LiCl
- ClШаблон:SubP(CHШаблон:Sub)Шаблон:SubPClШаблон:Sub + 4 PhLi → PhШаблон:SubP(CHШаблон:Sub)Шаблон:SubPPhШаблон:Sub + 4 LiCl
Coordination chemistry and use as co-catalyst
The diphosphine serves as a bidentate ligand forming six-membered CШаблон:SubPШаблон:SubM 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
- ↑ Шаблон:Cite journal
- ↑ Шаблон:OrgSynth
- ↑ Шаблон:Cite encyclopedia
- ↑ 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. Шаблон:Doi