In the last decade, transition‐metal catalyzed C−H functionalization reactions have progressed enormously, becoming a useful tool in organic synthesis and a practical alternative to well‐established methodologies. Very recently, research efforts have also been devoted to developing more sustainable C−H functionalization protocols, in order to increase their applicability. One of the most promising approaches in this sense is represented by the substitution of common reaction media with bio‐based solvents. In the present contribution a general perspective on the benefits of this approach is given, followed by key literature examples.

The effect of the addition of ionic liquids (ILs) during the hydrodistillation of Myristica fragrans Houtt. (nutmeg) essential oil was studied. The essential oil of M. fragrans is characterized by the presence of terpenes, terpenoids, and of phenylpropanoids, such as methyl eugenol and safrole, that are regarded as genotoxic and carcinogenic. The aim of the work was to determine the best ionic liquid to improve the yield of the extraction of M. fragrans essential oil and decrease the extraction of toxic phenylpropanoids. Six ILs, namely 1,3-dimethylimidazolium chloride (1), 1,3-dimethylimidazolium dimethylphosphate (2), 1-(2-hydroxyethyl)-3-methylimidazolium chloride (3), 1-(2-hydroxyethyl)-3-methylimidazolium dimethylphosphate (4), 1-butyl-3-methylimidazolium chloride (5), and 1-butyl-3-methylimidazolium dimethylphosphate (6), were prepared by previously reported, innovative methods and then tested. An experimental design was used to optimize the extraction yield and to decrease the phenylpropanoids percentage using the synthesized ILs. The influence of the molarity of ILs was also studied. MODDE 12 software established 0.5 M 1-butyl-3-methylimidazolium chloride as the best co-solvent for the hydrodistillation of M. fragrans essential oil.