Phenethylzinc bromide is primarily utilized in organic synthesis as a reagent for the introduction of the phenethyl group into various organic molecules. It is particularly valuable in organometallic chemistry for forming carbon-carbon bonds, enabling the construction of complex molecular structures. This compound is often employed in cross-coupling reactions, such as Negishi coupling, where it facilitates the efficient and selective synthesis of pharmaceuticals, agrochemicals, and fine chemicals. Its reactivity with electrophiles makes it a useful tool for creating intermediates in drug development and material science. Additionally, it is applied in the synthesis of natural products and polymers, contributing to advancements in both industrial and academic research.