Nucleophilic Aromatic Substitution

Nucleophilic aromatic substitution (SNAr), which can operate through several different reaction mechanisms, is considered one of the preferred methods to derivatize arenes. Despite great advances in transition metal-catalyzed arene functionalization, SNAr remains an attractive option due to simplicity, low cost, and avoidance of metal contamination of the product. The scope of this reaction is guided by three basic principles: electron deficiency at the reactive carbon on the aromatic system, nature of the leaving group to be displaced, and reactivity of the nucleophile. This chapter is organized by the types of nucleophile and nature of the product generated. The nucleophiles covered include oxygen, sulfur, nitrogen, and halogen. The chapter highlights the most important reactions, addressing basic principles, advantages/disadvantages of the methodology, mechanism, and techniques for achieving laboratory success. It discusses the preparation of ortho-arynes.