Recent Advances in Transition Metal‐Catalyzed Functionalization of <i>gem</i>‐Difluoroalkenes
Suvajit Koley, Ryan A. Altman
Abstract
Abstract gem ‐Difluorinated alkenes are readily accessible building blocks that can undergo functionalization to provide a broad spectrum of fluorinated and non‐fluorinated products. Herein, we review recent (since 2017) transition metal‐catalyzed transformations of these specialized alkenes and summarize general reactivity patterns of these reactions. Many transition metal‐catalyzed reactions undergo net C−F bond functionalization reactions to deliver monofluorinated products. These reactions typically proceed through β ‐fluoroalkylmetal intermediates that readily eliminate a β ‐fluoride to deliver monofluoroalkene products. A second series of reactions exploit coinage metal fluorides to add F − to the gem ‐difluorinated alkene, and further functionalization delivers trifluoromethyl‐containing products. In stark contrast, few transition metal‐catalyzed reactions proceed in net “fluorine‐retentive processes” to deliver difluoromethylene‐based products.