Step economy strategy for the synthesis of amphoteric aminoaldehydes, key intermediates for reduced hydantoins

Despite of the orthogonal reactivity of the N-H aziridines aldehyde, these compounds exist as an equilibrium of three different forms - whereas the dimeric one is mostly observed in a variety of solvents. In this work, we have developed an alternative protocol for the aminoaldehyde dimers synthesis in two steps starting with an organocatalyzed aziridination between alpha,beta-unsaturated aldehydes and a protected amine to afford known isolable and stable N-protected aziridine aldehydes. After Boc-deprotection, dimeric species were immediately formed from monomeric N-H aziridine aldehydes. From this building-block new reduced hydantoins were prepared via {[}3+2]-annulation with isocyanates. (AU)