Deoxygenative Amination of Azine‑N‑oxides with Acyl Azides via [3 + 2] Cycloaddition
journal contributionposted on 16.01.2020, 17:04 by Dongeun Kim, Prithwish Ghosh, Na Yeon Kwon, Sang Hoon Han, Sangil Han, Neeraj Kumar Mishra, Saegun Kim, In Su Kim
A transition-metal-free deoxygenative C–H amination reaction of azine-N-oxides with acyl azides is described. The initial formation of an isocyanate from the starting acyl azide via a Curtius rearrangement can trigger a [3 + 2] dipolar cycloaddition of polar N-oxide fragments to generate the aminated azine derivative. The applicability of this method is highlighted by the late-stage and sequential amination reactions of complex bioactive compounds, including quinidine and fasudil. Moreover, the direct transformation of aminated azines into various bioactive N-heterocycles illustrates the significance of this newly developed protocol.