Synthesis of enantiomerically pure ethylenediamines from chiral sulfinimines: a new twist to the Strecker reaction

Addition of various cyanide nucleophiles on chiral t-butylsulfinimine and p-tolylsulfinimine derivatives are described and demonstrated that aliphatic t-butylsulfinimines are excellent substrates for a new variant of the Strecker reaction where cyanide ions are delivered through ethylisopropoxyaluminum cyanide or trimethylsilylcyanide combined with a Lewis acid catalyst. The reaction proceeds with high yield and high diastereoselectivity, which can be further improved by additional crystallizations.