Acyclic Amino Acids Catalyzed Direct Asymmetric Aldol Reactions in Aqueous Media Assisted by 2,4-Dinitrophenol

Abstract

The catalytic capabilities of acyclic amino acids for the direct asymmetric aldol reactions assisted by 2,4-dinitrophenol in aqueous media were investigated. Several acyclic amino acids catalyzed asymmetric aldol reactions with excellent stereoselectivity, and afforded the corresponding β-hydroxy ketones in high yields and up to 99% ee. Our result suggested that the L-isoleucine was the most effective one. A systematic investigation of exploring the catalytic efficiency of natural acyclic amino acids for the asymmetric aldol reactions in aqueous media assisted by 2,4-dinitrophenol was reported. The result demonstrated that the L-isoleucine was the most effective one, which catalyzed asymmetric aldol reactions to afford the corresponding β-hydroxy ketones in high yields and up to 99% ee.