<i>Cinchona</i> Organocatalyzed Enantioselective\nAmination for Quaternized Serines as Tertiary Amides

Herein, we describe a <i>Cinchona</i>-aminocatalyzed\nenantioselective α-hydrazination of an α-formyl amide\nfor the production of protected quaternized serines as tertiary amides\nwith <i>ee</i>’s of generally >98% and ≤99%\nyields. The proposed TS model supported by density functional theory\ncalculations involves a quinuclidinium ion Brønsted acid-assisted\ndelivery of D<sup><i>t</i></sup>BAD, which occurs from the <i>Re</i> face of an H-bonded enaminone when using a 9<i>S</i>-cinchonamine catalyst, resulting in a hydrazide with the <i>R</i>-configuration as determined by X-ray analysis.