Corey–House Reaction

Corey–House Reaction (Corey–Posner–Whitesides–House)

Introduction: The Corey–House reaction is a reliable method for making carbon–carbon single bonds by coupling alkyl fragments using organocuprate reagents (Gilman reagents). The reaction is useful for forming higher alkanes.

General Reaction

2 R–Li + CuI  →  R2CuLi  (Gilman reagent)

R2CuLi + R'–X → R–R' + R–Cu + LiX

(X = Br, Cl, I)

Mechanism (Short)

The reaction follows an SN2-type nucleophilic substitution on an alkyl halide. One alkyl group of the Gilman reagent couples with the electrophilic carbon, forming a new C–C bond.

• Formation of R2CuLi from organolithium and CuI
• Nucleophilic substitution on R'–X
• New C–C bond formed

Scope

• Best with primary alkyl halides
• Secondary moderate
• Tertiary not suitable (elimination)
• Aryl/vinyl halides usually unreactive

Example:

C2H5Li + CuI → (C2H5)2CuLi

(C2H5)2CuLi + C3H7Br → C5H12

Advantages

• Forms C–C bonds under mild conditions
• Good for making larger alkanes

Limitations

• Organolithiums are moisture sensitive
• Poor functional group tolerance
• Modern Pd-couplings have broader scope

Teaching Question

• Compare Corey–House vs Suzuki/Negishi for different substrates.