Corey–House synthesis

The Corey–House synthesis (also called the Corey–Posner–Whitesides–House reaction and other permutations) is an organic reaction that involves the reaction of a lithium diorganylcuprate (${\displaystyle {\ce {R_{2}CuLi}}}$) with an organic halide or pseudohalide (${\displaystyle {\ce {R'-X}}}$) to form a new alkane, as well as an ill-defined organocopper species and lithium (pseudo)halide as byproducts.

Li⁺[R–Cu–R]⁻ + R′–X → R–R′ + "R–Cu" + LiX

In principle, a carbanion equivalent such as an organolithium or Grignard reagent can react directly (without copper) with an alkyl halide in a nucleophilic substitution reaction to form a new carbon–carbon bond. However, aside from the use of metal acetylides as nucleophiles, such a process rarely works well in practice due to metal–halogen exchange and/or the formation of large amounts of reduction or elimination side-products. As a solution to this problem, the Corey–House reaction constitutes a general and high yielding method for the joining of two alkyl groups or an alkyl group and an aryl group.