Thiol−Ene Reaction: Synthetic Aspects and Mechanistic Studies of an Anti‐Markovnikov‐Selective Hydrothiolation of Olefins

In synthetic organic chemistry, the anti-Markovnikov thiol-ene click (TEC) reaction has emerged as a powerful and widely used approach to build carbon-sulfur (C-S) bonds owing to several inherent benefits, including simple synthetic procedures, high atom economy with no side products, and easy purification, which results in the formation of linear thioethers in high yield under mild reaction conditions. These TEC reactions have numerous trapping applications in the field of nanoengineering, polymer science, and in medicinal chemistry for the synthesis of many drugs and bioactive molecules. This present review highlights the diversity of TEC reaction in terms of substrates, catalysts and mechanistic studies towards the generation of highly selective anti-Markovnikov adduct under metal-free, metal-catalyzed, and photo-induced reaction conditions.