Nickel/Cobalt-Catalyzed C(sp³)–C(sp³) Cross-Coupling of Alkyl Halides with Alkyl Tosylates

The C(sp3)–C(sp3) cross-coupling of alkyl halides with alkyl tosylates has been developed by employing a combination of nickel and nucleophilic cobalt catalysts in the presence of a manganese reductant. This method provides a straightforward route to a diverse set of not only secondary–primary but also primary–primary C(sp3)–C(sp3) linkages under mild conditions without using alkyl-metallic reagents. Mechanistic studies suggest the formation of alkyl radicals from both alkyl halides and alkyl tosylates. Additionally, cross-coupling could be applied to the short-step synthesis of a histone deacetylase inhibitor, Vorinostat.