Flow synthesis approaches to privileged scaffolds - recent routes reviewed for green and sustainable aspects

Privileged scaffolds as starting points toward biologically active molecules represent a neuralgic point in drug discovery. The ability of synthetic chemists concerned with their generation should be flanked by robust technologies enabling the efficient synthesis and decoration of large libraries for extensive screenings and for scale-up processes. The use of continuous flow chemistry in the pharmaceutical chemistry sector may facilitate privileged scaffold generation and implementation of more efficient multistep transformations which can contribute to developing green and sustainable processes. This review discusses the use of flow chemistry applied to the synthesis of privileged scaffolds, considering also sustainability and green chemistry aspects. Flow protocols are discussed in a unified fashion such as to facilitate effective comparison between both the various chemical approaches used on the one hand, and the chosen technical solutions across the various works on the other hand. The review also offers an authors’ perspective on potential future directions in the field.