Aza-Henry reaction of substituted nitroalkanes using α-formamidoaryl sulfones as N-acylimino equivalents

Base-promoted elimination of p-toluenesulfinic acid from N-formamidoaryl sulfones leads to the corresponding N-acylimines that react with primary and secondary nitronate anions giving anti-β-formamido nitroderivatives in good yields and high diastereoselectivity.