Recent Advances in Phosphonium Salt Catalysis

Quaternary phosphonium salts have been extensively used in organic synthesis as Lewis acid organocatalysts. This review covers recent applications of phosphonium salts as Lewis acidic catalysts for Mannich, Strecker, and Friedel-Crafts reactions for the formation of C C bonds, annulation reactions, etc., allowing the construction of structurally diverse and synthetically useful architectures. 1. Introduction 2. C C Bond-Forming Reactions: Mannich, Strecker, and Friedel-Crafts Reactions 3. Annulation Reactions: [2+ 1], [2+ 1+ 1], [3+ 2], [4+ 1], and [4+ 2] Reactions 4. Other Reactions: Acylation, Hydrosilylation, Protonation, and Polymerization Reactions 5. Conclusion

Automated summary

Quaternary phosphonium salts are extensively used as Lewis acid organocatalysts in organic synthesis, particularly for Mannich, Strecker, and Friedel-Crafts reactions, allowing the construction of structurally diverse and synthetically useful architectures.