Functionalization of Heteroarenes Under Continuous Flow

Aromatic heterocycles are omnipresent motifs in pharmaceutical and agrochemical structures. Functionalization of these ring systems is an important part of many synthetic procedures. In this chapter, an overview is given of how microflow technology has been employed as a powerful tool for the diversification of heteroarenes. An emphasis is put on fine chemical synthesis, although reactor design and problem solving will be discussed when relevant, as it comprises an important part of the research field. Pragmatic translations to microflow are reviewed for existing functionalization protocols, and a few elusive reactions are highlighted that cannot be performed satisfyingly in batch mode.