Phenylboronic acid

Description

Phenylboronic acid, also known as benzeneboronic acid, is synthesized through the reaction of the Grignard reagent PhMgBr with B(OMe)3. This compound and its derivatives with aryl substitutions are widely recognized as essential building blocks in the field of synthetic organic chemistry. They are particularly prominent in the Suzuki coupling reaction, where a boronic acid reacts with an organic halide to form a carbon-carbon bond. Additionally, the reactions of boronic acids with 1,2- and 1,3-diols are significant for saccharide recognition, highlighting their versatility in chemical applications.

Chemical properties

white to light yellow crystal powder. Insoluble in water and benzene, easily soluble in ether and methanol. When exposed to air or under heating conditions, it is easy to dehydrate and form a three-molecular polymer.

The Uses of Phenylboronic acid

Phenylboronic Acid is a compound used in organic synthesis of various pharmaceutical goods.
Phenylboronic acid (PBA) and its derivatives can bind sugars and other diol compounds to form cyclic boronate esters. These esters bear negative charges. Due to this reaction, sugars can be detected by means of electrochemical and optical techniques.
PBA modified electrodes have been constructed as reagentless electrochemical sensors. There, PBA is absorbed on the electrode surface either as a self- assembled monolayer film ore a polymer thin film. Basically, for optical detection techniques for the detection of sugars, PBA is modified with a chromophore that should change its properties on reaction with a sugar.

Reaction of Phenylboronic acid with a sugar

The Uses of Phenylboronic acid

Reagent used for• ;Rhodium-catalyzed intramolecular amination1 • ;Pd-catalyzed direct arylation2 • ;Mizoroki-Heck and Suzuki-Miyaura coupling reactions catalyzed by palladium nanoparticles3 • ;Palladium-catalyzed stereoselective Heck-type reaction4 • ;Highly effective Palladium-catalyzed arylation Suzuki-Miyaura cross-coupling in water5 Reagent used in Preparation of• ;Ni(II) pincer complex and Pd(II) pyridoxal hydrazone metallacycles as catalysts for the Suzuki-Miyaura cross-coupling reactions6,7• ;N-type polymers for all-polymer solar cells8 •

The Uses of Phenylboronic acid

Phenylboronic acid is a versatile compound that is soluble in water, allowing for coupling reactions to be performed in aqueous environments. This solubility, along with its compatibility with various organic substituents such as esters, ketones, and alcohols, makes it a preferred choice over Grignard reagents in certain coupling reactions.

Furthermore, phenylboronic acid and its derivatives have the ability to form complexes with polyol compounds, including saccharides and poly(vinyl alcohol) (PVA). This property is particularly useful in the development of glucose-sensitive materials. For instance, a copolymer containing phenylboronic acid moieties can be synthesized through the copolymerization of 4V-vinyl-2-pyrrolidone (NVP) and 3-(acryl-amide)phenylboronic acid (PBA). The formation of complexes between this NVP-PBA copolymer and PVA is crucial for constructing glucose-sensitive insulin release systems. These systems are designed to dissociate in response to changes in glucose concentration, providing a mechanism for controlled insulin delivery.

The utility of phenylboronic acid in the creation of glucose-sensitive hydrogels and its role as a ligand for glucose targeting exemplify its importance in the development of advanced materials for healthcare applications.

Definition

ChEBI: Phenylboronic acid is a member of boronic acids. It is functionally related to a boronic acid.

Synthesis Reference(s)

Organic Syntheses, Coll. Vol. 4, p. 68, 1963
The Journal of Organic Chemistry, 49, p. 5237, 1984 DOI: 10.1021/jo00200a045

General Description

Phenylboronic acid (PBA) is an organoboronic acid with unique properties. It functions as a molecular receptor, capable of binding to compounds that contain a cis-diol group. This ability makes it a valuable component in various chemical reactions.

One notable application is in the microwave-assisted Suzuki coupling process, where aryl chlorides are coupled with phenylboronic acid. This reaction takes place in the presence of a Pd/C catalyst and uses water as the solvent, offering an efficient and environmentally friendly method for synthesizing biaryls.

Safety Profile

Poison by intravenous andintraperitoneal routes. Moderately toxic by ingestion.Mildly toxic by skin contact. When heated to decomposition it emitsacrid smoke and irritating fumes.