Optimization of blue LED Photo-Flow synthesis in continuous flow reactors using design of experiments (DoE): Efficient synthesis of diverse diaryl ketones

[Display omitted] •Design of Experiments (DoE) reaction optimization.•Indigenous device design for micro & millifluidic reaction set-up.•Blue-LED-induced C-C bond formation.•Devoid of usage of metals, bases, and acids.•Robust synthesis of a library of diaryl ketones under mild sustainable reaction condition. 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.