Efficient Nickel Precatalysts for Suzuki‐Miyaura Cross‐Coupling of Aryl Chlorides and Arylboronic Acids Under Mild Conditions
Morgan E. John, Michael J. Nutt, Josephine Offer, Jeremy Duczynski, Ken Yamazaki, Tomoya Miura, Stephen A. Moggach, George A. Koutsantonis, Reto Dorta, Scott G. Stewart
Abstract
Abstract The synthesis and catalytic properties of Ni(II) complexes with the general formula Ni(NHC)[P(OR) 3 ](Ar)Cl are described. These complexes are air‐stable and extremely effective precatalysts in the Suzuki‐Miyaura cross‐coupling reaction. The reaction protocols described allow for the cross‐coupling of aryl chlorides and arylboronic acids, employing low catalytic loading, to deliver a large variety of functionalized biaryl compounds. For the coupling of aryl chlorides with N ‐heterocyclic boronic acids, TBAF was used as an additive to afford nitrogen‐containing biaryl products. Overall, these reaction protocols operate at room or mild temperatures and can be applied to a variety of electronically and sterically differentiated coupling partners. Fundamental insights into the mechanism of this reaction, including the proposed formation of the catalytically active Ni(NHC)[P(O i ‐Pr) 3 ] and resting state species, are also reported.