Highly Stereoselective Synthesis of Optically Pure C-Aryl Imines from α-l-Amino Acid Methyl Esters

Abstract

The title compounds were easily synthesized starting from readily available α-l-amino acid methyl esters in excellent overall yields. The key feature of the methodology here reported was the TiCl₄ mediated condensation of the 4-methoxybenzaldehyde with the free α amino function of the amino acid derivatives. This process was clean and highly stereoselective, and the corresponding enantiomerically pure chiral imines were recovered without need of chromatographic procedures.

Keywords:

• Aryl amines
• Amino acid methyl esters
• Titanium tetrachloride
• Stereoselectivity

Acknowledgments

This work was supported by MIUR financial grants.