BF3·OEt2-Catalyzed Synthesis of anti-β-(N-Arylamino)-α-hydroxynitriles by Regio- and Diastereospecific Ring Opening of 3-Aryloxirane-2-carbonitriles with Anilines

A safe and convenient synthetic method to anti-beta-(N-aryl-amino)-alpha-hydroxynitriles from 3-aryloxirane-2-carbonitriles and anilines was developed under the catalysis of BF3 center dot OEt2 in ethanol. In this method, BF3 center dot OEt2 first reacts with ethanol to produce the true catalyst of super acid H[B(OEt)F-3], followed by an acid-catalyzed regio- and diastereospecific ring opening of oxirane-2-carbonitriles with anilines, generating anti-beta-(N-arylamino)-alpha-hydroxynitriles. The method features the advantages of non-metal catalysis, short reaction times, and easy operation, and uses an environmentally friendly solvent.