Cobalt-Mediated Dinitrogen Functionalization via Isolable Diazenido Intermediates toward N=P and N=C Bonds Formation

Rui Feng, Zhaoxin Li, Hai-Jun Li, Dajiang Huang, Wanxin Chen, Zhenfeng Xi and Junnian Wei*

CCS Chem. 2026, doi.org/10.31635/ccschem.026.202608098

        The direct transformation of dinitrogen (N2) into value-added organonitrogen compounds remains a fundamental challenge in chemistry. Herein, we report the isolation of cobalt diazenido intermediates generated from dinitrogen functionalization at a ferrocenyldiphosphine-supported cobalt platform. In the presence of excess PMe3, these species undergo further transformation to furnish the iminophosphorane Me3P=NTMS, thereby providing a rare 3d-metal-mediated entry from N2 to organophosphorus compounds. Moreover, reaction with isonitrile gives the corresponding N2-derived carbodiimide product, further demonstrating the reactivity of these diazenido intermediates. IBO analyses show that the Co-N bond in diazenido complex 3a is highly covalent and involves one σ-type and two π-type components. DFT calculations support the involvement of a cobalt imido species as a key intermediate in these downstream transformations, while mechanistic studies indicate that under strongly reducing and silylating conditions, a competing side pathway leading to N(TMS)3 can also occur.