Herein, we demonstrated the optimization of a blue LED (450 nm) induced C-C bond formation between various aryl and heteroaryl aldehydes with 1,4-quinones at room temperature in ethyl acetate using Design of Experiments (DoE). This reaction was conducted within a flow (micro and milli-fluidic) device using a millifluidic meandering channel reactor (MC2), resulting in a library of diversely substituted diaryl ketones with moderate to good yields. Control experiments and density functional theory (DFT) based computational investigations were performed to elucidate the reaction mechanism.