Searching for novel reusable biomass-derived solvents: furfuryl alcohol/water azeotrope as a medium for waste-minimised copper-catalysed azide-alkyne cycloaddition

Herein, we report the first application of the furfuryl alcohol/water azeotrope as a sustainable and easily recoverable reaction medium in organic chemistry. The applicability of this novel medium was tested in copper-catalysed azide-alkyne cycloaddition (CuAAC), a reaction usually conducted in mixtures of water and an organic solvent. Our reaction conditions allowed the isolation of the expected triazoles in generally good yields and usually in shorter times compared to classical reaction conditions, also proving a wide substrate scope. A large fraction of the furfuryl alcohol/water azeotrope can be recovered by simple distillation at the end of the reaction, which results in a dramatic decrease in waste production and E-factors, compared to typically employed CuAAC procedures.