Simple Synthesis Of Chiral γ-Amino Acids

Efficient routes to chiral, monosubstituted γ-amino acids—a long-standing synthetic challenge—have been developed independently by two groups. When the researchers found that they were each working on the same problem, they cooperated with each other to publish simultaneously instead of racing to be first. Chiral γ-amino acids are widely used building blocks to create drugs and foldamers, biomolecule-like compounds with well-defined conformations. These amino acids are commonly synthesized with chiral auxiliaries, which have to be removed in a separate step. Now, Samuel H. Gellman's group at the University of Wisconsin, Madison, and Helma Wennemers and coworkers at Switzerland's University of Basel have developed enantioselective conjugate addition reactions of aldehydes to nitroethylene using different organocatalysts—a prolinol derivative and a tripeptide, respectively (J. Am. Chem. Soc., DOI: 10.1021/ja800345r and 10.1021/ja801027s). The basic reaction (shown) efficiently produce highly enantioenriched γ-amino acids.