Corey-House synthesis

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.


 * R2CuLi + R'-X → R-R'

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.

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.