Carbocatalysing the Preparation of N-Rich Heterocycles with an Unprecedented Mechanism

Carbon is demonstrated as a mild and transition metal free catalyst for the preparation of N-rich heterocyclic compounds for the first time. The surface > C=O groups on nanodiamonds were identified as an active site, which most probably generates imidogene as a reactive species that triggers the reaction. The experimental results supported with density functional theory calculations were used to reveal a new reaction pathway, different from the conventional homogeneous one that indicates involvement of nitrogen radicals in the reaction. (c) 2018 Elsevier Ltd. All rights reserved.