Sustainable flow approaches to active pharmaceutical ingredients

The adoption of flow conditions has been the object of growing attention from both academia and industry. The shift from batch to continuous-flow technology is very stimulating from a cultural and technological point of view. Flow technologies represent a rare opportunity for creating new proprietary access routes to complex target compounds and at the same time, they offer an incredible opportunity for increasing the efficiency of known processes that lead to modern, more sustainable future chemical production. While the general utility of flow conditions is truly convincing, its applicability assumes even greater relevance in the synthesis of Active Pharmaceutical Ingredients (APIs) due to the complexity of the targets and their high commercial value and also the highly selective chemistry involved. This review highlights the key features of flow chemistry in the synthesis of APIs by describing all the relevant literature in the field over the last 5 years, up to mid-2020. Key chemical aspects of the processes, the equipment used, and the features of the flow procedure are presented.