Homogeneous manganese-catalyzed hydroamination of alkenes via the reductive coupling with nitroarenes

Abstract

We report an efficient and operationally simple protocol for the manganese-catalyzed synthesis of secondary amines via the reductive coupling of nitroarenes and alkenes. Only commercially available reagents were required, and excellent to moderate results were achieved with styrenes, which have been identified as challenging substrates under this strategy. Moreover, both electron-donating and electron-withdrawing groups were relatively well accommodated for both coupling partners, and no second reductive treatment was necessary. Additional mechanistic studies revealed a homogeneous system, operating through a radical pathway, with a carbon-centered radical and a nitroso species (derived from alkene and nitro compound, respectively) as the key reactive species.