Fluoroalcohol-water two-phase systems: A new green solvent for organic synthesis

A solvent is the common medium for running organic reactions due to, easy control over mass and heat transference, stabilization of transition states, and fast modification of reactivity (rate,selectivity, etc.). To avoid the drawbacks of conventional organic solvents, new media have been investigated, all of them having a certain number of advantages, as well as disadvantages [1]. Green solvents can be considered the ideal solvents, because they are verynontoxic, non flammable, biorenewable, and safe for humans and the environment. Various solvents have been proposed as a green solvents such as a water, fluoro alcohol,supercritical fluids, biomass-derived solvents, ionic liquids, and deep eutectic solvent [2]. In this work,fluoroalcohol-water system (two-phase) as a new green solvent has been described. The addition of organic reactants to aqueous solutions of fluoroalcohol (FA) leads to the formation of a two-phase system with one phase enriched in FAand the organic reactant and another largely aqueous phase. These systems were used as a reaction medium for isocyanide-based multicomponent reactions. Excellent yields were achieved in the presence of large amounts of water (10–20 % FA v/v). Surprisingly, the reactions performed in the two-phase systems outperformed those in pure (100%) FA or water. The presence of the aqueous phase offers advantages over single-phase reaction media in terms of driving the reaction and product recovery.