Chemistry:Herrmann's catalyst

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Herrmann's catalyst
HerrmannCat.png
Identifiers
ChemSpider
UNII
Properties
C46H46O4P2Pd2
Molar mass 937.66 g·mol−1
Appearance yellow solid
Melting point 123-125 °C
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Herrmann's catalyst is an organopalladium compound that is a popular catalyst for the Heck reaction. It is a yellow air-stable solid that is soluble in organic solvents. Under conditions for catalysis, the acetate group is lost and the Pd-C bond undergoes protonolysis, giving rise to a source of "PdP(o-tol)3".

The complex is made by reaction of tris(o-tolyl)phosphine with palladium(II) acetate:[1]

2 Pd(OAc)2 + 2 P(C6H4-2-CH3)3 → 2 HOAc + Pd2(OAc)2[P(C6H4-2-CH2)(C6H4-2-CH3)2]2

Many analogues of Hermann's catalyst have been developed, e.g. palladacycles obtained from 2-aminobiphenyl.[2]

References

  1. Herrmann, W. A.; Brossmer, C.; Reisinger, C.-P.; Riermeier, T. H.; Öfele, K.; Beller, M. (1997). "Palladacycles: Efficient New Catalysts for the Heck Vinylation of Aryl Halides". Chemistry – A European Journal 3: 1357–1364. doi:10.1002/chem.19970030823. 
  2. Bruneau, A.; Roche, M.; Alami, M.; Messaoudi, S. (2015). "2-Aminobiphenyl Palladacycles: The "Most Powerful" Precatalysts in C–C and C–Heteroatom Cross-Couplings". ACS Catalysis 5: 1386–1396. doi:10.1021/cs502011x.