An air-stable binary Ni(0)-olefin catalyst

Nickel complexes are of ever-increasing importance in organic synthesis; however, unstable Ni(COD)(2) is still the main Ni(0) source used. Here the authors report a solution to this long-standing issue: an air stable Ni(0) complex that acts as a general precatalyst for numerous nickel-catalysed reactions. Nickel catalysis has become a growing and empowering area of research in recent years, providing new reactivity modes towards organic synthesis. In these endeavours, Ni(COD)(2) (bis(1,5-cyclooctadiene)Ni(0)) vastly dominated this area, thus becoming the main source of Ni(0) for exploring new catalytic reactivity. However, all known Ni(0)-olefin precatalysts suffer from great instability and fast decomposition when exposed to air. With the aim of providing fast and facile technologies for practitioners, herein we report the synthesis, characterization and reactivity of an air stable binary Ni(0)-olefin complex, Ni((F)stb)(3). This 16-electron complex features a unique arrangement of simple ligands that shield the nickel centre from oxygen. We demonstrate that Ni((F)stb)(3) is an excellent precatalyst in a wide variety of important nickel-catalysed transformations and has unexpected catalytic properties compared with other Ni(0)-olefin complexes. As a general, practical and air-stable Ni(0) precursor, Ni((F)stb)(3) represents a solution to a 60-year quest.