The synthesis of nitrogen‑containing molecules through C–N bond formation is critical for the discovery and preparation of medicines, agrochemicals, and materials.¹ Herein, we report the direct insertion of a nitrogen atom into unactivated carbon-carbon double bonds to access aza‑allenium intermediates, which can be converted into either nitriles or amidines depending on the initial alkene substitution pattern.² This operationally simple and highly functional‑group‑tolerant reaction is effective across a wide range of unactivated alkenes. Mechanistic investigations, including targeted trapping experiments, support the proposed pathway and highlight the synthetic value of these electrophilic intermediates. In particular, allylic nucleophiles engage the aza‑allenium species in efficient 5‑endo‑trig cyclizations, delivering previously inaccessible semisaturated N‑heterocycles with inverse Baldwin selectivity.³ Together, these findings establish a general blueprint for constructing diverse nitrogen‑containing scaffolds through direct nitrogen insertion and controlled interception of reactive intermediates derived thereof.

[1] E. Vitaku, D. T. Smith, J. T. Njardarson, J. Med. Chem. 2014, 57, 10257.

[2] Y. Brägger, A.-S. K. Paschke, N. Nasiri, B. B. Botlik, F. Felician, B. Morandi, Science 2025, 387, 1108.

[3] Y. Brägger, E. Tufano, P. Gärtner, A.-S. K. Paschke, D. T. Egger, M. C. Amberg, L. Sorrentino, B. Morandi. Submitted.