Beyond Organometallic Flow Chemistry: The Principles Behind the Use of Continuous-Flow Reactors for Synthesis

Flow chemistry is typically used to enable challenging reactions which are difficult to carry out in conventional batch equipment. Consequently, the use of continuous-flow reactors for applications in organometallic and organic chemistry has witnessed a spectacular increase in interest from the chemistry community in the last decade. However, flow chemistry is more than just pumping reagents through a capillary and the engineering behind the observed phenomena can help to exploit the technology's full potential. Here, we give an overview of the most important engineering aspects associated with flow chemistry. This includes a discussion of mass-, heat-, and photon-transport phenomena which are relevant to carry out chemical reactions in a microreactor. Next, determination of intrinsic kinetics, automation of chemical processes, solids handling, and multistep reaction sequences in flow are discussed. Safety is one of the main drivers to implement continuous-flow microreactor technology in an existing process and a brief overview is given here as well. Finally, the scale-up potential of microreactor technology is reviewed.