Deconstructive di-functionalization of unstrained, benzo cyclic amines by C–N bond cleavage using a recyclable tungsten catalyst

With H2WO4 as the catalyst and H2O2 as the oxidant, we herein report a deconstructive difunctionalization of the C-N bond in unstrained, benzo cyclic amines to generate an ester group and nitro group simultaneously. The preliminary mechanistic studies suggested that the corresponding hydroxamic acid is the key intermediate for this transformation. Importantly, with the utilization of this transformation, we achieved an interesting approach for the ring contraction of quinoline to indole, an example of scaffold hopping in a hetero- aromatic system.