Methylboronic acid (CAS 13061-96-6) is a versatile organoboron intermediate widely used in organic synthesis, pharmaceutical chemistry, and material science. As a key building block in Suzuki-Miyaura cross-coupling reactions, it enables efficient C–C bond formation for constructing complex molecules, including natural products, pharmaceutical agents, and functional materials. It reacts with hydroxyl and amine groups to form boronate esters, serving as protective groups or molecular recognition elements in sensing and catalysis. In drug discovery, it is utilized in synthesizing boron-containing therapeutics, such as proteasome inhibitors and antibacterial agents, leveraging boron’s unique Lewis acidity and binding properties. It also acts as a catalyst in polymerization and selective oxidation reactions, improving reaction efficiency and selectivity. In agrochemicals, it serves as an intermediate for herbicides and fungicides. Additionally, it is applied in surface modification and polymer blending to enhance material compatibility and thermal stability.

Methylboronic acid is a low-toxic irritant (GHS07; H315, H319, H335). Inhalation of dust may cause respiratory irritation (cough, sore throat, shortness of breath); use local exhaust and dust masks. Skin contact can lead to redness, itching, or mild dermatitis; wear nitrile gloves and wash skin thoroughly after handling. Eye contact causes severe irritation (stinging, tearing, redness); immediately rinse eyes with running water for ≥15 minutes and seek medical help if symptoms persist. Ingestion may result in nausea, abdominal pain, or diarrhea; do not induce vomiting and consult a physician if large amounts are swallowed. No evidence of carcinogenicity or reproductive toxicity. Store away from strong oxidants, acids, and incompatible substances. Dispose of waste per local hazardous waste regulations; avoid release to the environment.