Optimized and Scalable Synthesis of BOPYRENPY Chromophores: Access to a Seven-Membered BF 2 –C 60 Dyad for Reactive Oxygen Species Generation

We report an optimized and scalable synthesis of BOPYRENPY, a seven-membered BF2-chelated chromophore, improving yields from 10% to almost 90%, on a multigram scale via acetonitrile-mediated stabilization of BF3 intermediates. This approach enabled the first covalently linked seven-membered BF2−C60 dyad, previously inaccessible due to low precursor availability. Optical and electrochemical studies demonstrate efficient intramolecular energy and electron transfer to the fullerene triplet state, driving the generation of reactive oxygen species (ROS) and establishing a new heavy-atom-free triplet photosensitizer platform for ROS-mediated applications.