Hydroamination of alkenes with dinitrogen and titanium polyhydrides.

Abstract

An ideal synthesis of alkyl amines would involve the direct use of abundant and easily accessible molecules such as dinitrogen (N₂) and feedstock alkenes^1-4. However, this ambition remains a great challenge as it is usually difficult to simultaneously activate both N₂ and a simple alkene and combine them together through carbon-nitrogen (C-N) bond formation. Currently, the synthesis of alkyl amines relies on the use of ammonia produced through the Haber-Bosch process and prefunctionalized electrophilic carbon sources. Here we report the hydroamination of simple alkenes with N₂ in a trititanium hydride framework, which activates both alkenes and N₂, leading to selective C-N bond formation and providing the corresponding alkyl amines on further hydrogenation and protonation. Computational studies reveal key mechanistic details of N₂ activation and selective C-N bond formation. This work demonstrates a strategy for the transformation of N₂ and simple hydrocarbons into nitrogen-containing organic compounds mediated by a multinuclear hydride framework.