Wurtz Reaction: 2R-X + 2Na → R-R + 2NaX (dry ether)

• Best for symmetrical alkanes (same R group)
• Mixed Wurtz (R-X + R'-X + Na) gives mixture of R-R, R'-R', and R-R' (poor yield of cross product)
• Side reactions: Elimination competes, especially with 2° and 3° halides

Corey-House Synthesis (better for unsymmetrical coupling): R-X + 2Li → R-Li (organolithium) 2R-Li + CuI → R2CuLi $\frac{Gilman reagent}{lithium dialkylcuprate}$ R2CuLi + R'-X → R-R' + RCu + LiX

This gives cross-coupling products selectively. R'-X should be primary for best yield.