Aldehydes and Ketones Influence Reactivity and Selectivity in Nickel-Catalyzed Suzuki-Miyaura Reactions

We show that the energetically-favorable coordination of aldehydes and ketones – but not esters – to nickel(0) during Suzuki-Miyaura reactions can lead either to exquisite selectivity and enhanced reactivity, or to the inhibition<br>of the reaction. Aryl halides where the C-X bond is connected to the same π-system as an aldehyde or ketone functional<br>group undergo unexpectedly rapid oxidative addition, and are selectively cross-coupled during inter- and intramolecular<br>competition reactions. When aldehydes and ketones are present elsewhere, such as in the form of exogenous additives,<br>the cross-coupling reaction is inhibited depending on how strongly the pendant carbonyl group can coordinate to nickel(0). This work advances our understanding of how common functional groups interact with nickel(0) catalysts, and presents synthetic chemists with a tool that can be used to achieve site-selectivity in functionalized molecules. <br>