“…37,38 The recent development of water-soluble catalysts assists in promoting several catalytic reactions in water such as cross coupling reactions, C–H activation, hydroformylation reactions, oxidation/reduction, rearrangement reactions, etc . 39–45 Detailed mechanistic studies were carried out to understand these processes in the aqueous phase and based on the solubilities of the substrate/catalyst, reactions using water as a solvent were classified as “in water”, “on water” or micellar catalysis. 46–49 For example, the process will be called “on water” if there is no solvation of the reaction components and an “in water” reaction is one where the presence of any additives assists the solubilization of the otherwise insoluble substrates/catalysts, etc .…”