An efficient one pot ipso-nitration: structural transformation of a dipeptide by N-terminus modification

Abstract

The one pot ipso-nitration of Boc-capped rigid dipeptide Boc-Maba-Aba-OMe 1 gave poor yields under excess NaNO₂ in dilute mineral acidic medium at 0 °C. The yield is improved with the use of a catalytic amount of CuSO₄. The N-terminus modification leads to structural transformation of the dipeptide from anti parallel to parallel β-sheet. We have also explored the reverse reaction by one pot reduction of nitro group to amine and Boc protection.