Palladium-Catalyzed Intramolecular meta -C–H Arylation Assisted by Nitrile Templates Under Microwave-Accelerated Conditions Accessing Fluorene Frameworks

Although intermolecular meta-C–H arylation has been thoroughly studied and well established, the intramolecular version of meta-C–H arylation is still largely unexplored and offers exciting opportunities for future research. With these considerations, we describe a palladium-catalyzed intramolecular meta-C–H arylation of 3-(4-benzylphenyl)propanoates, enabled by both aliphatic and aromatic nitrile templates under microwave-assisted conditions. This approach provides an efficient alternative pathway to fluorene frameworks via template-directed meta-C–H arylation. The method afforded fluorene derivatives exclusively in good to excellent yields. Additionally, postsynthetic modifications are used to access cyclopenta[b]fluorenones.