Single-Flask Enantioselective Synthesis of -Amino Acid Esters by Organocatalysis

An operationallysimple Knoevenagel condensation/asymmetricepoxidation/dominoring-opening esterification (DROE) approach has been disclosed tosuccessfully access a good variety of (R)- and (S)-& alpha;-arylglycine esters from commercially availablealdehydes, phenylsulfonyl acetonitrile, cumyl hydroperoxide, anilines,and readily available Cinchona alkaloid-based catalystsusing a single solvent and reaction vessel. DFT calculations performedon the key asymmetric epoxidation showed the importance of cooperativeH-bonding interactions in affecting the stereocontrol.