Skeletal editing through direct nitrogen deletion of secondary amines

Nitrogen is 'deleted' from secondary amines using anomeric amide reagents, which react with the amine to form an isodiazene, after which nitrogen gas is released and the resulting carbon radicals combine to form a carbon-carbon bond. Synthetic chemistry aims to build up molecular complexity from simple feedstocks(1). However, the ability to exert precise changes that manipulate the connectivity of the molecular skeleton itself remains limited, despite possessing substantial potential to expand the accessible chemical space(2,3). Here we report a reaction that 'deletes' nitrogen from organic molecules. We show that N-pivaloyloxy-N-alkoxyamides, a subclass of anomeric amides, promote the intermolecular activation of secondary aliphatic amines to yield intramolecular carbon-carbon coupling products. Mechanistic experiments indicate that the reactions proceed via isodiazene intermediates that extrude the nitrogen atom as dinitrogen, producing short-lived diradicals that rapidly couple to form the new carbon-carbon bond. The reaction shows broad functional-group tolerance, which enables the translation of routine amine synthesis protocols into a strategy for carbon-carbon bond constructions and ring syntheses. This is highlighted by the use of this reaction in the syntheses and skeletal editing of bioactive compounds.

Automated summary

This reaction successfully removes nitrogen from organic molecules, promoting carbon-carbon coupling reactions and expanding the accessible chemical space.