Beyond Aziridines: Complex Photoinduced Cycloaddition Reactions via Nitrene Intermediates

• Applicant: Professor Dr. Rene M. Koenigs
• Subject Area: Organic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 579291611

The synthesis of amines is one of the central objectives of modern organic chemistry, as nitrogen-containing molecules play indispensable roles in pharmaceuticals, agrochemicals, fine chemicals, and functional materials. This research proposal aims to expand the chemical space of nitrene transfer reactions beyond the established aziridination manifold. By exploiting the unique electronic structure of triplet nitrenes and accessing them under photochemical and photocatalytic conditions, entirely new reactivity modes will be studied. The central concept of the proposed research is the design of relay strategies, in which the diradical reactivity of a triplet nitrene is systematically channeled into subsequent transformations. In this way, nitrenes act not only as reactive species for direct functionalization, but also as initiators of complex cascade reactions that enable the efficient construction of molecular architectures otherwise difficult to access. These cascades will combine nitrene reactivity with the distinctive features of unsaturated systems, strained-ring frameworks, and reactive carbon intermediates. By integrating these complementary elements, the project aims to establish a versatile and general platform for constructing complex nitrogen-rich heterocycles. The impact of this research extends well beyond fundamental methodology. Expanding nitrene transfer chemistry into new reactivity paradigms will provide synthetic chemists with powerful new tools for the rapid and selective construction of functionalized molecules. Such methodologies hold significant promise for applications in medicinal chemistry or the synthesis of natural products. In the long term, the insights gained into the control of highly reactive intermediates under photochemical conditions will help define new principles for reaction discovery, further strengthening the role of triplet nitrene chemistry in modern synthesis methods.

• DFG Programme: Research Grants