Synthesis 2008(16): 2519-2526  
DOI: 10.1055/s-2008-1067189
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Chiral N-Phosphonyl Imine Chemistry: Asymmetric Addition of Ketone-Derived Enolates for the Synthesis of β-Amino Ketones

Jianlin Han, Teng Ai, Guigen Li*
Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-106, USA
Fax: +1(806)7421289; e-Mail: guigen.li@ttu.edu;
Further Information

Publication History

Received 6 March 2008
Publication Date:
24 July 2008 (online)

Abstract

New chiral N-phosphonyl imines have been synthesized in good yields under convenient reaction conditions. These chiral N-phosphonyl imines can serve as efficient electrophiles for asymmetric addition reactions with lithium ketone enolates. Good chemical yields and excellent diastereoselectivities were obtained for twelve examples. The N-1-naphthyl group of the chiral auxiliary was found to be superior to its benzyl counterpart in controlling the diastereoselectivity for this reaction. The chiral auxiliary can be readily removed by treatment with aqueous HBr in methanol at room temperature to give free β-amino ketones in high yields.