The Application of Micro Reactors for Chemical Synthesis: How small is required?

The miniaturisation of chemical reactors offers many fundamental and practical advantages of relevance to the chemical industry, who are constantly searching for controllable, information rich, high throughput, environmentally friendly methods of producing products with a high degree of chemical selectivity. In this paper a number of chemical reactions will be used to illustrate the advantages that micro reactors offer for the rapid optimisation of reactions, in which the product is typically produced in both higher yield and purity. It will be illustrated that compounds may be prepared and purified within an integrated system and that it is possible to generate intermediates in situ within the reactor, which may then be subsequently reacted to produce more complex products. More recently the incorporation of solid supported reagents and catalysts has been investigated. It will be illustrated that the ‘scale out’ of micro reactors may be used to generate larger quantities of compound without having to re-optimise the reaction, thus saving time and money whilst simultaneously making the process inherently safe. Furthermore, integration of the microfluidic system with analytical detection will be illustrated, enabling in situ process control to be achieved.