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.
Cyclopropane is the smallest cyclic compound with unique structural features and physicochemical properties, which is widely used in the design of small molecule drugs. In drug design, it is often used to increase activity, fix conformation and improve PK and water solubility. The introduction of cyclopropyl groups into drugs can change various properties of molecules, such as improving metabolic stability; increasing biological activity; enhancing drug efficacy; limiting polypeptide conformation and slowing down its hydrolysis; reducing plasma clearance; improving drug dissociation and many more. Cyclopropane rings are widely found in marketed drugs, including cardiovascular drugs, central nervous system (CNS) drugs, anticancer drugs, autoimmune and anti-inflammatory drugs.