Base-Controlled Diastereoselective Synthesis of Either <i>anti</i>- or <i>syn</i>-β-Aminonitriles

Deprotonation of secondary alkane nitriles with nBuLi and addition to aryl imines gives kinetic anti-β-aminonitriles. Use of LHMDS allows reversible protonation of the reaction intermediate to give <i>syn</i>-β-aminonitriles. The pure diastereosiomers can be isolated in good yields, and the mechanism was elucidated.