Molecular Sculpting: A Multipurpose Tool for Expedited Access to Various Fluorinated Arenes via Photocatalytic Hydrodefluorination of Benzoates.

Abstract

Starting with highly fluorinated benzoates, we develop the directed photocatalytic hydrodefluorination (HDF) of fluorinated aryl benzoates and demonstrate its synergistic use with other HDF strategies, along with C-H arylation, decarboxylative coupling, and decarboxylative protonation, to access most fluorination patterns found in benzoate derivatives and by extension benzene derivatives via a molecular sculpting approach. Mild reaction conditions and excellent regioselectivity make the approach ideal for synthesis. This approach provides access to 16 benzoate derivatives with different fluorination patterns from just a couple of highly fluorinated, commercially available benzoic acids. We synthesize key intermediates or the active pharmaceutical ingredient for sitagliptin, diflunisal, and other pharmaceutically important molecules. Importantly, we provide key insights into relative rates of defluorination and strategies to alter these rates. We provide demonstrations of the synergistic use of HDF and related technologies to rapidly enhance the synthetic complexity of these simple commercially available perfluoroarenes to form complex partially fluorinated molecules.