The application of the Pd-catalyzed oxidative C-H olefination of arenes, also known as the Fujiwara-Moritani reaction, has traditionally been limited by the requirement for directing groups on the substrate or the need to use the arene in large excess, typically as a (co)solvent. Herein the development of a catalytic system is described that, through the combined action of two complementary ligands, makes it possible to use directing-group-free arenes as limiting reagents for the first time. The reactions proceed under a combination of both steric and electronic control and enable the application of this powerful reaction to valuable arenes, which cannot be utilized in excess.

The nondirected C(sp2)−H activation of simple arenes has advanced significantly in recent years through the discovery of new catalyst systems that are able to perform transformations with the arene as the limiting reagent. Important developments in catalyst and ligand design that have improved reactivity and selectivity are reviewed.

Phenylacetylenes are key structural motifs in organic chemistry, which find widespread applications in bioactive molecules, synthetic intermediates, functional materials, and reagents. These molecules are typically prepared from prefunctionalized starting materials, e.g. using the Sonogashira coupling, or using directing groupbased C−H activation strategies. While highly efficient, these approaches remain limited by their inherent selectivities for specific regioisomers. Herein we present a complementary approach based on an arene-limited nondirected C−H activation. The reaction is predominantly controlled by steric rather than electronic factors and thereby gives access to a complementary product spectrum with respect to traditional methods. A broad scope as well as the suitability of this protocol for latestage functionalization are demonstrated.

We report the ligand‐enabled C−H activation/olefination of free carboxylic acids in the γ‐position. Through an intramolecular Michael addition, δ‐lactones are obtained as products. Two distinct ligand classes are identified that enable the challenging palladium‐catalyzed activation of free carboxylic acids in the γ‐position. The developed protocol features a wide range of acid substrates and olefin reaction partners and is shown to be applicable on a preparatively useful scale. Insights into the underlying reaction mechanism obtained through kinetic studies are reported.

Aromatic nitriles are key structural units in organic chemistry and, therefore, highly attractive targets for C–H activation. Herein, the development of an arene-limited, nondirected C–H cyanation based on the use of two cooperatively acting commercially available ligands is reported. The reaction enables the cyanation of arenes by C–H activation in the absence of directing groups and is therefore complementary to established approaches.