Trimesitylborane is widely used as a Lewis acid catalyst in organic synthesis, particularly in reactions involving the activation of carbonyl compounds and hydrosilylation processes. Its bulky structure enhances selectivity and stability, making it effective in promoting transformations under mild conditions. It is also employed in frustrated Lewis pair (FLP) chemistry, where it participates in the activation of small molecules like hydrogen and carbon dioxide, enabling metal-free catalytic hydrogenation and CO₂ fixation. Additionally, trimesitylborane serves as a reagent in the generation of boron-containing intermediates for materials science and pharmaceutical research.