Chemistry (Weinheim an der Bergstrasse, Germany)

One-step synthesis of racemic α-amino acids from aldehydes, amine components, and gaseous CO2 by the aid of a bismetal reagent.

PMID 23184625


α-Amino acids are essential resources for human life and are highly useful as building blocks for organic synthesis. The core framework of an α-amino acid can be divided into three basic components: an aldehyde, an amine, and carbon dioxide (CO(2)). We report herein that a one-step synthesis of α-amino acids has been successfully achieved from these three basic and inexpensive chemicals with a single operation, in which the mixture of an aldehyde, a sulfonamide, and gaseous CO(2) was heated at 100 °C in the presence of Bu(3)Sn-SnBu(3) and CsF. In this one-pot sequential protocol, two important intermediates (imine and α-amino stannane) are involved and the stannyl anion generated in situ plays a crucial role, particularly for the efficient stannylation of the imine in the presence of proton sources and for promoting retrostannylation of the undesired α-alkoxy stannane owing to its high stability and tolerance of the presence of proton sources. This methodology enabled the synthesis of a wide range of racemic arylglycine derivatives in high yields.