FAST AND EFFICIENT ACETALIZATION OF ALDEHYDES MEDIATED BY REUSABLE NATURAL DEEP EUTECTIC SOLVENTS

ChCl /malonic acid 1/1 a NatuRAL Deep Eutectic Solvent(NADES) has been used as efficient and recyclable catalysts for protection of carbonyls to 1,3-dioxane, showing good results with several substrate as aliphatic aldehydes and aromatic aldehydes, bearing electron-withdrawing and electron-donating groups at different positions of the arene ring. These results emerge to the capability of the NADES, used as solvent, to detain the water from the reaction mixture and his acidity which allow us to not use external acid catalyst. Test of recycle have been done on the NADES ChCl/malonic acid 1/1 and the results show us that the system can be reused until five time without appreciable loss of activity. Further studies on the obtainment of cyclic acetals from ketones and of other saturated heterocycles bearing different heteroatoms than oxygen (e.g. nitrogen, sulfur), are currently under development. Also, it would be highly desirable the setup of one-pot acetalization/functionalization process in DES environment, together with the reverse hydrolysis reaction of the acetals in NaDES/water mixtures.