Investigating the reactivity of nitrous oxide with lithiated hydrazines: application to the synthesis of diarylethanes from diarylmethylhydrazines†

In this study, we investigate the reactivity of nitrous oxide (N₂O) with lithiated diarylmethylhydrazines, leading to the formation of diarylethanes via dinitrogen extrusion. The reaction proceeds through the formation of a lithium oxytetrazene adduct generated by the interaction of the lithium salt of diarylmethylhydrazines with nitrous oxide. Upon heating at 60 °C, this adduct efficiently converts into diarylethane in good yields. Experimental data (IR, UV) and density functional theory (DFT) calculations support the formation of the lithium oxytetrazene intermediate, which subsequently eliminates lithium hydroxide and nitrogen gas, yielding diarylethane. This method demonstrates broad substrate tolerance, accommodating substituted hydrazines with both electron-donating and electron-withdrawing groups, as well as cyclic and unsymmetrical hydrazines.