Synthesis of fluorine-containing bicyclo[4.1.1]octenes <i>via</i> photocatalyzed defluorinative (4 + 3) annulation of bicyclo[1.1.0]butanes with <i>gem</i>-difluoroalkenes

Although bicyclo[4.1.1] systems are privileged scaffolds in many natural products and drug molecules, efficient synthetic approaches to these systems remain underdeveloped. In this work, we disclose a photoredox-catalyzed defluorinative (4 + 3) annulation of bicyclo[1.1.0]butanes with <i>gem</i>-difluoroalkenes, which provides practical and straightforward access to the fluorine-containing bicyclo[4.1.1]octenes. Our protocol is characterized by mild conditions, broad substrate scope, excellent functional group tolerance and good to excellent yields. Notably, the ease and variety of product derivatizations further enrich the diversity and complexity of the fluorine-containing bicyclo[4.1.1] systems.