Synthesis of hydrazinopeptides using solid-phase N -electrophilic amination: extension to the Fmoc/tert -butyl strategy and chemistry of the N-N bond in strong acid media

Abstract
The synthesis of hydrazinopeptides using solid‐phase N‐electrophilic amination was extended to the Fmoc/tert‐butyl strategy. Both Boc/benzyl and Fmoc/tert‐butyl strategies led to the isolation of by‐products arising from the partial instability of the N–N bond during the final cleavage and deprotection step. Two paths of decomposition have been shown: the cleavage of the N–N bond leading to the regeneration of the amine and a Hofmann‐type elimination yielding original dianisyl adducts. Our data suggest that the Fmoc/tert‐butyl strategy is better suited for the synthesis of hydrazinopeptides.