Chemical Properties

yellow solid

Uses

Dichloro[bis(1,4-diphenylphosphino)butane]palladium(II) is used for the catalysis of styrene carbonylation, coupling of alkyl Grignard reagents with organic halides, selective monoalkylation of organic polyhalides, and modification of the dihalovinyl moiety of synthetic pyrethroids.

Preparation

Dichloro[1,4-bis(diphenylphosphino)butane]palladium(II) (1,4-Bis(diphenylphosphino)butane-palladium(II) chloride) can be prepared conveniently in situ by mixing the bidentate phosphine ligand and (PhCN)2PdCl2 in either benzene or chloroform.^[1] The preparation of (dppb)PdCl2 is also possible through the reaction of PdCl2 with dppb in acetone, a process that slowly forms the catalyst as a white precipitate which can be isolated in 51% yield.^[2] Preparation of the hydrate complex is possible via the reaction of Na2[PdCl4] with dppb in a mixture of CH2Cl2 and water.

reaction suitability

core: palladium
reaction type: Buchwald-Hartwig Cross Coupling Reaction
reaction type: Cross Couplings
reaction type: Heck Reaction
reaction type: Hiyama Coupling
reaction type: Negishi Coupling
reaction type: Sonogashira Coupling
reaction type: Stille Coupling
reaction type: Suzuki-Miyaura Coupling
reagent type: catalyst

Synthesis

Example 3 Step 1: 10 mL of palladium sponge was mixed with concentrated hydrochloric acid and concentrated nitric acid in a 3:1 volume ratio until the palladium sponge was completely dissolved. 37% concentrated hydrochloric acid was added to the solution and filtered to remove insoluble material while treating the brown nitrogen oxides produced. The filtrate was concentrated to a solution of chloropalladium acid with a palladium concentration of 0.5 g/mL. Step 2: An N,N-dimethylformamide solution of bis(diphenylphosphino)butane was prepared by adding 44 g of 1,4-bis(diphenylphosphino)butane to 100 mL of N,N-dimethylformamide, and heating to 50°C. The N,N-dimethylformamide solution of bis(diphenylphosphino)butane was then heated to 50°C. Step 3: The chloropalladium acid solution prepared in step 1 was added dropwise to the bis(diphenylphosphino)butane solution in step 2 under stirring. The reaction was stirred at 50 °C for 60 minutes. After completion of the reaction, the reaction solution was cooled and filtered, and the filter cake was collected. Step 4: The filter cake obtained in Step III was washed with anhydrous ethanol and then dried under vacuum at 50 °C for 4 h. A light yellow 1,4-bis(diphenylphosphino)butane-palladium(II) chloride complex (C28H28Cl2P2Pd) of 56.1 g was obtained in 98.9% yield.

References

1. Sugi, Y.; Bando, K.-I. CL 1976, 727.
2. Sanger, A. R. JCS(D) 1977, 1971.