(tert-Butoxycarbonylmethylene)triphenylphosphorane is widely used in organic synthesis, particularly in the Wittig reaction, where it facilitates the formation of α,β-unsaturated tert-butyl esters from aldehydes or ketones. This reagent is especially valuable in the synthesis of complex organic molecules, including natural products and pharmaceuticals, due to its ability to introduce a protected carboxylic acid functionality via the tert-butyl ester group, which can be deprotected under acidic conditions. It is also employed in the preparation of peptide intermediates and other biomolecules, allowing for the incorporation of unsaturated ester moieties in multi-step syntheses. Additionally, its use in the modification of polymers and materials highlights its versatility in creating functionalized compounds with tailored properties.