Panel Discussion on FLOW CHEMISTRY

Continuous flow chemistry, which had been used in petrochemical and fine chemicals industry for many decades, entered the organic synthesis laboratories at the beginning of this century. Since then, numerous advances in this technology have been made, both from the knowledge and instrumentation viewpoints. This panel discussion provides a glance at the current trends and state of the art from an industrial perspective.

One of the main advantages of continuous flow reactors is their enhanced heat and mass transfers properties when compared to batch vessels. Thus, it is not surprising that most panelists find flow chemistry most useful to tackle highly exothermic and mixing-sensitive reactions. Transformations involving organometallic reagents such as Grignard and organolithium compounds, which may pose a safety concern in batch, can be carried out in flow in a safe and reliable manner. Biphasic gas-liquid reactions, such as catalytic hydrogenations, are also often mentioned as chemistries in which the implementation of flow reactors makes a difference. In addition to the enhanced mass-transfer characteristic of flow reactors, their capacity to readily operate under high pressure is also highly beneficial for this type of transformation. An additional application of continuous flow devices is the generation and in situ consumption of unstable, often hazardous intermediates, which can be carried out with increased safety due to the relatively low amount of intermediates present within the reactor.