Chiral phase-tranfer catalysis plays an important role in modern asymmetric synthesis and organic synthesis chemistry. This review focuses on the progress of chiral quaternary phosphonium salts as phase-transfer catalysts reported in recent years, and their application in asymmetric catalytic reactions, including Henry reaction, hydrophosphonylation reaction, alkylation reaction, Michael addition reaction, Mannich reaction, aldol reaction, protonation reaction and amination reaction. Steric and electrical effects of these catalysts are emphasized, future prospects for development of chiral quaternary phosphonium salts are also described in this article. Contents
1 Introduction
2 Early works
3 Chiral P-spiro tetraaminophosphonium salts and diaminodioxaphosphonium salts
3.1 Asymmetric Henry reaction
3.2 Asymmetric hydrophosphonylation reaction
3.3 Asymmetric alkylation reaction
3.4 Asymmetric Michael addition reaction
3.5 Asymmetric Mannich reaction
3.6 Asymmetric aldol reaction
3.7 Asymmetric protonation reaction
4 Chiral tetraalkylphosphonium salts
4.1 Asymmetric amination reaction of β-keto esters and benzofuranones
4.2 Asymmetric Michael addition reaction of 3-aryloxindoles
4.3 Asymmetric Mannich reaction of 3-aryloxindoles
5 Conclusion and outlook