Sustainable Approaches toward Valuable Chemicals by Transformation and Biotransformation of Monoterpenes and Monoterpenoids

Biomass offers a renewable alternative to fossil resources for producing fuels and chemicals, particularly when catalytic technologies reduce waste and energy input. Terpenes and terpenoids—abundant constituents of essential oils and resins—are attractive bio-based platforms because they combine structural diversity, high functionality, and intrinsic chirality, enabling access to value-added products in fewer synthetic steps. This review summarizes recent developments in the production of valuable chemicals through the catalytic transformation of abundant monoterpenes and monoterpenoids, focusing on isomerization, hydroformylation-based processes, and oxidation reactions. Special attention is given to green and sustainable strategies, particularly heterogeneous catalysis and biocatalysis.