An Indefinitely Air-Stable σ-NiII Precatalyst for Quantitative Cross-Coupling of Unreactive Aryl Halides and Mesylates with Aryl Neopentylglycolboronates

Three classes of Ni precatalysts based on pi-Ni-II, pi-Ni-0 and sigma-Ni-II complexes have been elaborated and employed in different laboratories for the functionalization and cross-coupling of otherwise inert aryl C-O, C-Cl, and C-F electrophiles. Various Ni precatalysts, ligands, boron sources, and reaction conditions that were developed in various research groups, necessitated the selection of the most suitable conditions for desired cross-coupling partners. Here a universal, bench-stable, easily prepared (NiCl)-Cl-II(1-naphthyl)(PCy3)(2)/PCy3 sigma-complex, for efficient and quantitative cross-coupling of aryl chlorides, bromides, iodides, mesylates, and fluorides with aryl neopentylglycolboronates is reported. This precatalyst will most probably help to advance the applications of Ni catalysis in organic, supramolecular, and macromolecular synthesis and will provide an easier access to the selection of reaction conditions for various transformations.