Continuous Flow Approach for Benzylic Photo-oxidations

This technical report presents a continuous flow approach for the aerobic photo-oxidation of benzylic substrates to produce ketones and aldehydes. The method utilizes UV-A LEDs at 375 nm in conjunction with a Corning advanced-flow reactor (AFR), which enhances gas-liquid mixing and achieves short residence times of approximately one minute. The report details the scalability of the process, demonstrating the production of multigram quantities of carbonyl products within a few hours. The continuous flow method is highlighted for its advantages over traditional oxidation techniques, primarily due to the use of air as an oxidant and sodium anthraquinone-2 sulfonate (SAS) as a water-soluble photocatalyst. The report outlines various experimental conditions and results, including substrate conversions and yields, while emphasizing the greener and safer reaction conditions that this approach offers for industrial applications. The findings indicate significant improvements in efficiency and selectivity for benzylic photo-oxidations compared to conventional methods.