Extrusion – back to the future: Using an established technique to reform automated chemical synthesis

Abstract

Herein, the benefits which extrusion can provide for the automated continuous synthesis of organic compounds are highlighted. Extrusion is a well-established technique that has a vital role in the manufacturing processes of polymers, pharmaceuticals and food products. Furthermore, this technique has recently been applied to the solvent-free continuous synthesis of co-crystals and coordination compounds including metal-organic frameworks (MOFs). To date, a vast amount of research has already been conducted into reactive extrusion (REX), particularly in the polymer industry, which in many cases has involved organic transformations, however, it has not received significant recognition for this. This review highlights these transformations and discusses how this previous research can be applied to the future of organic compound manufacture.

Multicomponent mechanochemical synthesis

“…These methods constitute an alternative approach to mechanochemical synthesis that can be performed as a flow process and thus be complementary to ball milling. Extrusion has traditionally been used in the polymer, pharmaceutical and food industries, but more recently it has also found application in the field of mechanochemical synthesis, in particular for the preparation of metal–organic frameworks and co-crystals, 7 but also in some examples of more conventional organic synthetic transformations. 8 …”

From Synthesis of Amino Acids and Peptides to Enzymatic Catalysis: A Bottom‐Up Approach in Mechanochemistry

“…Furthermore, the mechanoenzymatic approach was successfully applied fort he formation of nonpeptidic amide bonds (Scheme 14 b). In particular,t he utilization of twin-screw extrusion technology ( Figure 5), [59] which has demonstrated its value as an alternative for scaling-up numerous mechanochemical reac-Scheme13. [56] Building on this previous work, the same research team studied the mechanoenzymatic homo-oligomerization of amino acids in the ball mill.…”

“…[58] Scaling-up of the mechanoenzymatic homo-oligomerization of amino acids could be successfully carried out by extrusion techniques. In particular,t he utilization of twin-screw extrusion technology ( Figure 5), [59] which has demonstrated its value as an alternative for scaling-up numerous mechanochemical reac- tions, [60] enabled the synthesis on the gram-scale of the homo-oligopeptides 55.…”

Mechanoenzymatic Transformations in the Absence of Bulk Water: A More Natural Way of Using Enzymes

“…F) Mechanochemicalreaction carried out by twin-screw extrusion, showing the maincomponents of an extruder.G)Anexample of the screw configuration, adapted with permission from ref. [28].…”