Rapid Kinetic Screening via Transient Timesweep Experiments in Continuous Flow Reactors

Kinetic screenings and optimization of chemical reactions are of utmost importance to develop an understanding of underlaying reaction mechanisms. From a more practical point of view, they are needed to obtain a final product under the most efficient and optimal conditions possible. Flow chemistry and reaction automation are an excellent combination to reach these aims. Exploiting features of both concepts generate a highly efficient screening method. Monitoring the reaction during the transient stabilization from flow rate A to flow rate B results in a continuous sweep through all intermediate residence times. Real‐time analysis of the timesweeps gives a full kinetic profile of the chemical transformation carried out in the flow reactor. Transient timesweep experiments in continuous flow chemistry in conjunction with online monitoring allow for the recording of a wealth of kinetic data using minimal volumes of reactant at a minimum screening time required. The principle is introduced and discussed on the example of online benchtop NMR monitoring of a radical polymerization.