A new non-natural chiral auxiliary: design, synthesis, and resolution of 1-mesitylethylamine and its application in the asymmetric aza-Diels–Alder reaction
1-Mesitylethylamine was designed as a new non-natural chiral auxiliary. Racemic 1-mesitylethylamine could be synthesized in two steps from mesityl cyanide and could be resolved via separation of diastereomeric carbamates derived from (−)-menthyl chloroformate, followed by reduction with DIBAL and acidic hydrolysis. Imines, prepared from enantiopure 1-mesitylethylamine and aromatic aldehydes, reacted