The development of innovative, high-performance polymer materials requires monomers with unique functional groups that can promote their facile and effective polymerization. The use of functional phenolic styrene derivatives as polymer precursors has gained considerable attention because they can provide access to novel polymers with varied properties based on their functional groups. In addition, they derive from naturally occurring hydroxycinnamic acids 1 and are thus potentially renewable building blocks for polymers and materials. These acids are natural phenolic compounds that can be found in almost every plant. High concentrations of p-coumaric (1a), caffeic (1b), ferulic (1c) and sinapic acid (1d) can be found in berries, coffee, rice bran, and oilseed crops, respectively. While their concentrations in plants typically range from a few grams per kilogram of source material, they can also derive from highly abundant natural resources such as lignin, which is the second most abundant natural resource after cellulose. A prominent example of the current utilization of phenolic acid is the production of vanillin from ferulic acid. In the last years, biobased hydroxycinnamic acids have been receiving increasing interest as monomers for the manufacture of polymers. However, the steric hindrance around the substituted vinyl group is an obstacle to homopolymerization. Even though they can be copolymerized with less bulky monomers, their content in the produced copolymers is still very low due to the same reason. Condensation polymerization is an alternative but leads to the loss of hydroxy groups. While the direct polymerization of the biobased hydroxycinnamic acids is of limited efficiency, their decarboxylation gives rise to phenolic styrene derivatives 2. Due to the electronrich nature of their double bond, they can undergo polymerization via various mechanisms based on the functionality of the phenolic styrene derivative. The diversity of the different bio-based phenolic acids allows achieving different properties of the final product in order to meet specific demands. For instance, 4-vinylphenol (2a) derived from p-coumaric acid is used in polymer chemistry for the production of photoresists, adhesives and epoxy-curing agents. The decarboxylation product of caffeic acid, 4-vinylcatechol (2b), is a key monomer for adhesive materials inspired by mussel adhesive protein. Unfortunately, the hydroxy group is prone to induce side reactions, complicating the direct polymerization of these functional styrene derivatives. This complicates their isolation, storage, and polymerization. Furthermore, achieving controlled polymerization of phenolic styrenes is challenging.