Thiols are known for their strong odor and high toxicity, which makes the development of thiol-free alternatives for the construction of sulfur-containing derivatives, in particular sulfides (thioethers), highly desirable. Over the last few years, several approaches for the preparation of these compounds from alternative sources, such as DMSO, disulfides, elemental sulfur, Bunte salts, and N-substituted sulfanylsuccinimides, have been described. This critical review presents an in-depth analysis of the preparation of these derivatives, including the presentation of selected examples and the careful discussion of mechanistic pathways.

This feature article presents an overview of continuous flow chemistry, including photoflow and electroflow technologies in the preparation of active pharmaceutical ingredients (APIs) and fine chemical intermediates.