4-Phenoxyphenylboronic acid
[CAS# 51067-38-0]

Identification

• Classification: Chemical reagent >> Organic reagent >> Boric acid
• Name: 4-Phenoxyphenylboronic acid
• Synonyms: (4-Phenoxyphenyl)boronic acid
• Molecular Formula: C₁₂H₁₁BO₃
• Molecular Weight: 214.02
• CAS Registry Number: 51067-38-0
• EC Number: 687-755-5
• SMILES: B(C1=CC=C(C=C1)OC2=CC=CC=C2)(O)O

Properties

• Melting point: 141-145 ºC

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H315-H319-H335
• Precautionary Statements: P261-P264-P264+P265-P270-P271-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P319-P321-P330-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2A	H319

Discovory and Applicatios

4-Phenoxyphenylboronic acid is an aromatic boronic acid derivative, characterized by a phenoxy group attached to a phenyl ring, which is further connected to a boronic acid moiety. This compound has garnered interest in the field of organic synthesis and medicinal chemistry due to its role in cross-coupling reactions and the construction of complex organic molecules. Its discovery stems from the broader exploration of boronic acids, which are known for their versatility in forming carbon-carbon bonds, a key reaction in modern organic chemistry.

Boronic acids were first explored in the 19th century, but their widespread utility was realized with the development of the Suzuki-Miyaura coupling reaction, a powerful method for synthesizing biaryl compounds and other complex structures. 4-Phenoxyphenylboronic acid emerged as one of many boronic acid derivatives that could participate in such reactions, particularly due to the phenoxy substitution, which imparts unique electronic and steric properties to the molecule. These modifications allow for fine-tuning the reactivity and selectivity of the compound in various synthetic contexts.

The primary application of 4-Phenoxyphenylboronic acid lies in cross-coupling reactions, particularly the Suzuki-Miyaura reaction, where it serves as a coupling partner with halides or pseudohalides to form carbon-carbon bonds. This reaction is extensively used in the synthesis of biaryl compounds, which are core structures in pharmaceuticals, agrochemicals, and organic materials. The phenoxy group in this compound offers electronic stabilization, allowing for greater control over the reaction conditions and the outcome of the synthesis. As a result, 4-Phenoxyphenylboronic acid is a valuable reagent for constructing complex molecular architectures with high precision.

In medicinal chemistry, 4-Phenoxyphenylboronic acid is utilized in the development of biologically active molecules. The phenoxy and boronic acid functionalities are compatible with biological systems, allowing this compound to be used in the design of enzyme inhibitors and other therapeutic agents. Boronic acids, in general, are known for their ability to bind to diols and other biologically relevant groups, making them useful in the design of drugs that target enzymes such as proteases or kinases. 4-Phenoxyphenylboronic acid, in particular, has been explored as a building block in the synthesis of inhibitors for various diseases, including cancer and bacterial infections.

In materials science, 4-Phenoxyphenylboronic acid is used to synthesize polymers and other advanced materials. The phenoxy group offers increased stability and rigidity, making it ideal for creating materials with desirable mechanical and thermal properties. Additionally, the boronic acid moiety allows for the introduction of other functional groups or cross-linking with other materials, enabling the creation of polymers with tailored properties for specific industrial applications.

4-Phenoxyphenylboronic acid has also found utility in the field of sensors and diagnostics. Boronic acids have an affinity for diols, such as sugars, making them useful in designing sensors for glucose monitoring and other bioanalytical applications. The phenoxy group provides additional structural flexibility, enabling the fine-tuning of sensor properties for improved selectivity and sensitivity. This makes 4-Phenoxyphenylboronic acid a valuable component in the development of biosensors and diagnostic tools for medical and environmental applications.

The handling and storage of 4-Phenoxyphenylboronic acid require care, as boronic acids can be sensitive to moisture and air. Proper precautions, such as storing the compound under inert gas or in a desiccator, are necessary to maintain its stability and reactivity. Despite these considerations, the compound is relatively straightforward to handle in most synthetic environments, making it a popular choice among chemists working in academic and industrial laboratories.

In summary, 4-Phenoxyphenylboronic acid is a versatile compound with broad applications in organic synthesis, medicinal chemistry, materials science, and diagnostics. Its role in cross-coupling reactions, drug development, and material design highlights its significance as a valuable tool for creating complex, functional molecules.