Indazoles are a class of organic heterocyclic compounds, also known as 1,2-diazaindene and benzopyrazole. Indazole is a good bioisomer of phenol, which is more lipophilic than phenol and less prone to phase I and II metabolism. Indazole derivatives have a wide range of biological activities, and it has been confirmed that indazole compounds have anti-tumor, analgesic, anti-inflammatory and other drug activities. Anticancer is the most important application field of indazole drugs. Renal cell carcinoma, solid tumor, nausea and vomiting caused by chemotherapy and leukemia are the main indications of this structural backbone drug.
Borates are classified as critical materials, they are the main source of boron and have a variety of industrial applications. Organic trifluoroborate is stable to heat, air and humidity, and is a very convenient crystalline boric acid compound. Since it has a tetra-coordinated boronic acid structure after the substitution of fluorine, it does not exhibit Lewis acidity and is stable to oxidation conditions. In addition, it can be regarded as the protector of boronic acid and boronic acid ester, which can be converted into each other. The compound can generally exist stably in organic solvents, but will decompose in protic solvents to liberate trivalent boron, so it can be directly used as a substrate for Suzuki coupling. The difference between trifluoroborate and boric acid is that it must exist in a monomeric form, so the equivalent weight can be closely controlled.