Advantage of in situ generation of N-arylsulfonyl imines from α-amide sulfones in the phase-transfer-catalyzed asymmetric Strecker reaction

Highly efficient, catalytic enantioselective synthesis of N-arylsulfonyl α-amino nitriles from the corresponding α-amido sulfones has been achieved under toluene–aqueous potassium cyanide biphasic conditions using chiral quaternary ammonium iodide (R,R,R)-1 as an effective phase-transfer catalyst. This Strecker synthesis involving the in situ generation of the reactive N-sulfonyl imines is advantageous for the cyanation of the substrates having primary and secondary alkyl substituents.