N-Heterocyclic Carbene–Based Catalysts for Glycerol Valorisation: Current State and Perspectives

N-Heterocyclic carbenes (NHCs) are molecules with exceptional catalytic properties in a wide range of reactions. Recently, there has been a growing interest in using them as catalysts for biomass conversion. In this review, we examine the current state of glycerol valorisation (GV) using several catalytic systems, including metallic complexes bearing NHCs as ligands, polymeric building blocks and organocatalysts. The study covers literature published in the last 15 years, detailing the catalyst scope, reaction conditions and products of GV. This analysis emphasises the importance of varying the steric and electronic properties of NHCs within the reviewed catalytic systems. Furthermore, a critical evaluation of the proposed mechanistic pathways complements these results. A comprehensive understanding of the challenges of using such catalytic systems will emerge by compiling literature on the use of NHCs for the studied reactions. Additionally, this will promote new opportunities for further research in both academic and industrial fields.