4?Carboxyphenylboronic acid is a versatile boronic acid derivative widely used in organic synthesis, materials science, and biomedical research. Its dual functional groups (boronic acid and carboxylic acid) enable diverse chemical transformations. In organic synthesis, it is a key building block for Suzuki?Miyaura cross?coupling reactions, forming biaryl compounds in pharmaceutical and agrochemical synthesis. It undergoes esterification, condensation, and oxidation reactions to produce functionalized intermediates. In materials science, it modifies polymer surfaces, enhances adhesion, and prepares fluorescent quantum dots with pH?sensitive properties. It is used in synthesizing metal?organic frameworks (MOFs) and porous materials for gas storage and catalysis. In biomedicine, it serves as a glucose?sensing agent in biosensors, binding to diol groups in glucose. It also acts as a ligand for protein modification and drug delivery system development. Its high purity and reactivity make it essential in academic research and industrial manufacturing.

4?Carboxyphenylboronic acid is an irritant with mild toxicity, requiring careful handling. Skin contact causes redness, itching, and irritation; prolonged exposure may trigger allergic dermatitis. Eye contact leads to severe irritation, tearing, and conjunctival inflammation; direct exposure may damage the cornea. Inhalation of dust irritates the respiratory tract, causing cough, sore throat, and shortness of breath. Ingestion may result in nausea, vomiting, diarrhea, and abdominal pain; large doses may affect gastrointestinal function. It is hygroscopic, so store in sealed, dry containers away from moisture and incompatible substances (strong bases, oxidants). Wear nitrile gloves, safety goggles, and dust masks during operation; use in a well?ventilated area. In case of contact, rinse skin/eyes with plenty of water for 15 minutes; if ingested, drink warm water and seek medical attention. Avoid environmental release; dispose of waste per local hazardous waste regulations.