Metal-free and visible photons for the dehydrogenative N–N coupling of amines: powerful methods to synthesize optoelectronic materials

Abstract

Nitrogen–nitrogen bond containing molecules are ubiquitously present in bioactive natural products, drugs, and advanced materials. While the homo-N–N coupling of two NH moieties to form a hydrazine N–N bond is well developed, cross-dehydrogenative hetero-N–N coupling remains very unevolved. Herein, we report a visible-light-promoted intermolecular N–N coupling reaction that enables efficient coupling of Lewis basic secondary amines using N-iodosuccinimide (NIS) as the coupling mediator. This protocol facilitates not only the homo-coupling of identical amines but also the challenging hetero-coupling between different secondary amines, providing direct access to structurally diverse N–N linked architectures under remarkably mild conditions (room temperature, ambient atmosphere and metal-free). Significantly, the reaction demonstrates excellent scalability, allowing for gram-scale preparation of tetraphenyl hydrazines that exhibit pronounced fluorescence properties, thereby offering a new platform for advanced photoactive materials.