P-III/P-V=O-Catalyzed Intermolecular N-N Bond Formation: Cross-Selective Reductive Coupling of Nitroarenes and Anilines

An organophosphorus-catalyzed method for the synthesis of unsymmetrical hydrazines by cross-selective intermolecular N-N reductive coupling is reported. This method employs a small ring phosphacycle (phosphetane) catalyst together with hydrosilane as the terminal reductant to drive reductive coupling of nitroarenes and anilines with good chemoselectivity and functional group tolerance. Mechanistic investigations support an autotandem catalytic reaction cascade in which the organophosphorus catalyst drives two sequential and mechanistically distinct reduction events via P-III/P-V=O cycling in order to furnish the target N-N bond.

Automated summary

The reported method utilizes an organophosphorus catalyst and hydrosilane to drive the cross-selective intermolecular N-N reductive coupling of nitroarenes and anilines, with good chemoselectivity and functional group tolerance. Mechanistic investigations support an autotandem catalytic reaction cascade involving two sequential reduction events to produce the desired N-N bond.