N-Heterocyclic Carbene Derived Nickel-Pincer Complexes: Efficient and Applicable Catalysts for Suzuki-Miyaura Coupling Reactions of Aryl/Alkenyl Tosylates and Mesylates

Catalytic activities of NHC-derived nickel-pincer complexes for the Suzuki-Miyaura coupling reactions of aryl/alkenyl to-sylates and mesylates are described. In the presence of a catalytic amount of nickelacycle 1a, a wide array of tosylates and mesylates reacted with several aryl- and alkenylboronic acids to afford the coupling products, generally in high yields. Fine tuning of the reaction conditions for each class of electrophiles was achieved only by choosing the appropriate reaction medium (DME for tosylates, dioxane for mesylates). ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)