Corey-House synthesis
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The Corey-House synthesis (also called the Corey-House-Posner-Whitesides reaction) is an organic reaction that involves the reaction of a lithium dialkyl cuprate with an alkyl halide to form a new alkane.[1]
- R2CuLi + R'-X → R-R'
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[edit] Reaction mechanism
This reaction occurs in two steps. The alkyl halide is treated with lithium metal, and solvated in ether, which converts the alkyl halide into an alkyl lithium compound, R-Li. The starting R-X can be primary, secondary or tertiary alkyl halide:
- R-X + 2Li → R-Li + Li-X
The second step requires the alkyl lithium compound to be treated with cuprous iodide (CuI). This creates a lithium dialkyl cuprate compound. These compounds were first synthesized by Henry Gilman of Iowa State University, and are usually called Gilman reagents in honor of his contributions:
- 2RLi + CuI → R2CuLi + LiI
The lithium dialkyl cuprate is then treated with the second alkyl halide, which couples to the compound:
- R2CuLi + R'-X → R-R' + RCu + LiX
If second alkyl halide is not the same as the first, then cross-products are formed.
It is important to note that for this reaction to work successfully, the alkyl halide must be a methyl halide, benzyl halide, primary alkyl halide or a secondary cyclo alkyl halide. The relative simplicity of this reaction makes it a useful technique for synthesizing organic compounds.
[edit] Background
This reaction was developed by the co-operation of four organic chemists: E.J. Corey of Harvard University, Gary H. Posner of the Johns Hopkins University, G.M. Whitesides of MIT and Herbert O. House of the Georgia Institute of Technology.
[edit] References
- ^ Posner, G. H. "Substitution Reactions using Organo Copper Reagents" Organic Reactions 1975, 22, 253.
