Palladium-catalyzed transfer nitration using β-nitrostyrenes as organic nitro reagents

Abstract A palladium-catalyzed transfer nitration of haloarenes using β-nitrostyrene as an organic nitro reagent was developed. This protocol enables efficient and regioselective nitration of aryl bromides and chlorides under operationally simple conditions. The optimized catalytic system, consisting of Pd(cod)Cl2, tBuBrettPhos, and K3PO4 in DME, afforded a broad range of nitroarenes in high yields and exhibited excellent functional-group tolerance. Mechanistic investigations revealed that β-nitrostyrene releases nitrous acid under basic conditions, generating nitrite species in situ, which participate in the Pd-catalyzed coupling process.