Gilman Reagents (Organocuprates): 1,4‑Conjugate Addition to α,β‑Unsaturated Carbonyls

Master organocuprate (Gilman) conjugate addition: why it does 1,4-addition, enolate intermediate, and how to predict products vs Grignard.

• Reaction: α,β-unsaturated carbonyl + R2CuLi → β-substituted carbonyl
• What it does: Adds carbon nucleophile to β-carbon (conjugate addition)
• Typical reagents: Gilman reagent (R2CuLi), then protonation/workup
• Key intermediate: Enolate after 1,4 addition
• Driving force: Soft nucleophile preference; conjugate stabilization
• Exam type: Regiochemistry (1,4)
• Exam type: Reagent selection