Advancing green chemistry: from valorization of cashew nut shell liquid for surfactants to the synthesis of biologically relevant heterocycles

In this thesis, three distinct approaches have been explored inspired by the principles of green chemistry. The first approach focuses on the valorisation of plant biomass derived from CNSL (Cashew Nutshell Liquid), aiming to utilize industrial by-products as renewable raw materials. This strategy includes the valorisation of compounds present in CNSL, which were subsequently used to synthesize new biosurfactants., in collaboration with our industrial partner P&G Brussels. The other two approaches involve the development of novel, eco-friendly methods for synthesizing indole-fused polycyclic systems via both metal-assisted and classical organic reactions. Specifically, we reported the construction of two distinct structural motifs featuring the indole nucleus, which are common in many natural and synthetic biologically active compounds: tricyclic 2,3-dihydro-1H- pyrrolo[1,2-a]-indoles 3 (chapter 4.1) and 2,3-dihydropyrazino[1,2-a]indol-4(1H)-ones 5' . The synthesis of these two classes of compounds represents an efficient and sustainable method for producing valuable scaffolds using straightforward one-pot reactions from readily available building blocks such as 2-indolylmethylacetates. This approach eliminates the need for step-by-step synthesis, which often involves challenging isolation processes. Indole is a highly versatile pharmacophore, a unique heterocyclic compound with a wide range of pharmacological activities due to its diverse mechanisms of action. It stands out as a valuable component in drug discovery, possessing the unique ability to mimic various protein structures. In recent years, extensive research has been conducted to synthesize and explore the therapeutic potential of this nucleus. Due to its versatile nature and presence in a wide range of drug classes for various diseases, indole has gained significant popularity among organic and medicinal chemists. Numerous drug molecules containing the indole nucleus have been shown to be effective in the treatment of various diseases such as migraine, asthma, inflammatory diseases, cardiac arrhythmias and cancer, malaria, tuberculosis, and HIV