Here’s a list of common nucleophiles used in nucleophilic aromatic substitution (SNAr):
Oxygen nucleophiles
- –OH (hydroxide) → makes phenols
- –OR (alkoxides, e.g., –OCH₃) → makes aryl ethers
- –O⁻ from phenols → makes diaryl ethers
Nitrogen nucleophiles
- –NH₂ (amides, amines) → makes aryl amines
- –NR₂ (secondary/tertiary amines) → makes substituted aryl amines
Sulfur nucleophiles
- –SH (thiols) → makes aryl thioethers
- –SR (thiolates) → more reactive, also makes thioethers
Carbon nucleophiles
- –CN (cyanide) → makes aromatic nitriles (important in pharmaceuticals)
- Carbanions (like enolates, acetylides) → attach carbon groups to aromatics
Halide nucleophiles (less common)
- F⁻, Cl⁻, Br⁻, I⁻ → used in halogen exchange reactions (e.g., introducing fluorine for PET imaging)
In short:
Most common nucleophiles are –OH, –OR, –NH₂, –NR₂, –SR, –CN.