Effect of Halide Additives on Reaction Rate. First, we noted a shortcoming of the model system in the use of K2CO3 as base in that the reaction is heterogeneous. In order to monitor reaction kinetics with all components present, we replaced K2CO3 with 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU) as the base to achieve homogeneous reaction conditions for improved reproducibility. Importantly, we also found that although yields are reproducible in the Hepatochem photoreactor used in our previous work, the kinetics vary drastically by position, likely due to the asymmetric irradiation imposed by the reactor geometry. As such, we conducted kinetic studies in a custom 96-well plate photoreactor (See SI, Fig. ) which showed much improved reproducibility (% conversion standard deviation = 2.1%, n = 16. See SI, Section 6.1 for details) compared to the Hepatochem (standard deviation = 11%, n = 8).