Lignin Valorization via Acidolysis with Ethylene Glycol Stabilization

This thesis describes several aspects of lignin acidolysis with ethylene glycol stabilization and possible applications of the obtained monomers. An efficient strategy was developed to convert native lignin in lignocellulose to new lignin-derived platform chemicals (G/S-C2-acetals), a set of monomers that is not accessible via other lignin depolymerization or lignin-first methodologies, opening the door for interesting high value applications for lignin derived chemicals (Figure 7.1). Methodology development was performed with the specific aim of respecting green chemistry principles to obtain an overall new sustainable procedure for future biorefineries. As valuable use, the conversion of G-C2-acetal to homovanillyl alcohol and the subsequent conversion of a variety of biologically active amines was successfully demonstrated and allowed to produce a range of interesting chemicals, especially for the pharmaceutical field. Furthermore, lignin acidolysis was explored from the mechanistic perspective, providing insights on the different reactivity of guaiacyl and syringyl units through model compounds investigations and the great help of computational studies, paving the way for further optimization