Abstract
Over the past two decades, researchers have witnessed the synthesis of diaryl sulfides and diaryl selenides via transition metals-mediated carbon-heteroatom cross-coupling reactions in the presence of various organic and inorganic solvents. The use of water as a clean and environmentally friendly solvent in cross-coupling chemistry of C-S/Se bond formations has attracted profound interest owing to its availability, non-toxicity, low cost and renewability. The most commonly used solvents have been recognized as being of environmental concern, but the use of green and eco-friendly solvents like water is frequently considered with respect to the recovery of catalysts, isolation of products, and recycling. The fundamental interactions between the water and the transition metal catalysts or ligands are viewed from mechanistic aspects, which mostly favours the rational selection of high-performance and safe solvents. In this article, the authors intended to focus extensively on the critical role of water in various transition metals mediated C-S/Se cross-coupling methodologies.
