A General Pd-Catalyzed C2–H Arylation of Benzoxazoles with Highly Sterically Congested Aryl Chlorides Enabled by a Fittingly Tuned Ligand

The benzoxazole core, featuring a sterically congested 2,6-disubstituted aryl fragment at the C2 position, exhibits exclusive three-dimensional structures that are essential for particular applications in material science and pharmaceutical development. Despite their importance, the synthesis of these compounds has posed challenges with an efficient preparation strategy still lacking. In this study, we introduced a new indolylphosphine ligand, PCy₂-Man-phos, specifically designed to facilitate the C2-H arylation of benzoxazoles with sterically hindered aryl chlorides in general. The excellent functional group compatibility and rich arene substituted pattern enable the creation of highly decorated and sterically demanding 2-arylbenzoxazole frameworks, showing significant potential for diverse synthetic applications.