Stryker's reagent

Stryker's reagent

Identifiers
CAS number	33636-93-0
PubChem	12181933
Jmol-3D images	Image 1
SMILES C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.[CuH].[CuH].[CuH].[CuH].[CuH].[CuH]
Properties
Molecular formula	C₁₀₈H₉₆Cu₆P₆
Molar mass	1961.036406
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Stryker's reagent ([(PPh₃)CuH]₆^[1], also known as the Osborn complex, is a hexameric copper hydride ligated with triphenylphosphine.^[2] It is a brick red crystalline solid that is very sensitive to air. Stryker's reagent is a mild hydride source and is used in homogeneous catalysis of conjugate reduction reactions of various compounds (enones, enoates, etc).

Preparation and Stability

Stryker's reagent is prepared from copper(I) tert-butoxide, generated in situ from copper(I) chloride and sodium tert-butoxide, and pressurized hydrogen. It can be directly prepared from copper(II) salts as well.^[3] If stored under an inert atmosphere (e.g. argon, nitrogen) it has indefinite shelf life. Brief exposure to the oxygen does not destroy its activity significantly, although solvents used with Stryker's reagent should be rigorously degassed. It can effect highly regioselective conjugate reductions of various carbonyl derivatives including unsaturated aldehydes, ketones, and esters. This reagent was assigned as the "Reagent of the year" in 1991 for its functional group tolerance, high overall efficiency, and mild reaction conditions in the reduction reactions. Stryker's reagent is used in a catalytic amount where it is regenerated in the reaction in situ using a stoichiometric hydride source, often being molecular hydrogen or silanes ^[4]

Modifications to Stryker's reagent

Ligand modified versions of Stryker's reagent have been reported. These modifications claim to be more reactive and/or more stable in the atmosphere.

References

^ Mahoney, W.S.; Brestensky, D.M.; Stryker, J.M. (1988). "Selective Hydride-mediated conjugate reduction of α,β-unsaturated Carbonyl Compounds Using [(Ph₃P)CuH]₆". J. Am. Chem. Soc. 110: 291–293. doi:10.1021/ja00209a048.
^ Bezman, S. A.; Churchill, M. R.; Osborn, J. A.; Wormald, J. (1971). "Preparation and Crystallographic Characterization of a Hexameric Triphenylphosphinecopper Hydride Cluster". J. Am. Chem. Soc. 93 (8): 2063–2065. doi:10.1021/ja00737a045.
^ Lee, D. W.; Yun, J. (2005). "Direct synthesis of Stryker's reagent from Cu(II) salt". Tetrahedron Lett. 46 (12): 2037–2039. doi:10.1016/j.tetlet.2005.01.127.
^ e-EROS Encyclopedia of Reagents for Organic Synthesis http://www.mrw.interscience.wiley.com/eros/articles/rh011m/sect0-fs.html