3,5-Dibromophenylboronic Acid CAS 117695-55-3 | ≥98%

Suzuki–Miyaura Cross-Coupling

Versatile arylboronic acid building block for the palladium-catalysed Suzuki–Miyaura cross-coupling, where the boronic acid undergoes selective transmetalation with aryl halides, vinyl halides, and triflates to form new carbon–carbon bonds — the two meta-bromine substituents are retained intact under standard Suzuki conditions, providing orthogonal electrophilic handles for subsequent transformations.

• Chemoselective Suzuki coupling through the boronic acid while preserving both C–Br bonds, enabling sequential functionalisation strategies on the resulting 1,3,5-trisubstituted benzene scaffold.
• Compatible with aqueous, ligand-free, microwave-assisted, and room-temperature Suzuki protocols — the electron-withdrawing effect of the two bromine atoms modulates boron electrophilicity and influences transmetalation kinetics.
• Construction of meta-substituted biaryl products whose 1,3-dibromo motif is directly available for further palladium-, copper-, or nickel-catalysed cross-coupling, amination, or cyanation without additional halogenation steps.

Trifunctional Building Block & Sequential Cross-Coupling

One of the most strategically valuable trifunctional arene building blocks in modern synthetic chemistry — the boronic acid and two aryl bromides offer three independently addressable reactive sites on a single aromatic ring, enabling divergent elaboration through orthogonal coupling sequences.

• Sequential Suzuki → Suzuki or Suzuki → Sonogashira → Buchwald–Hartwig reaction cascades exploiting the differential reactivity of the B(OH)₂ (nucleophilic under Pd⁰ catalysis) and the two C–Br bonds (electrophilic under Pd⁰ catalysis) to assemble unsymmetrical 1,3,5-trisubstituted arenes in a programmable, step-economical fashion.
• Desymmetrisation of the two equivalent C–Br positions through stoichiometric control or selective monosubstitution under carefully tuned catalyst loading, enabling access to differentially substituted meta-terphenyl and 1,3,5-triarylbenzene architectures.
• Used as a three-directional core unit for the preparation of star-shaped molecules, tripodal ligands, and C₃-symmetric scaffolds where the 120° angular disposition of the three substituents is structurally or functionally essential.

Dendrimer, Polymer & Materials Science

The 1,3,5-trisubstituted benzene geometry makes this compound a key branching monomer for the construction of conjugated and non-conjugated macromolecular architectures with defined topology.

• AB₂-type monomer for the divergent or convergent synthesis of Fréchet-type and Newkome-type dendrimers — the boronic acid serves as the focal-point coupling handle while the two bromides propagate the dendritic growth.
• Building block for conjugated microporous polymers (CMPs), covalent organic frameworks (COFs), and porous aromatic frameworks (PAFs) assembled via Suzuki or Sonogashira polycondensation — the meta-connectivity enforces non-planar network topologies that increase surface area and gas-uptake capacity.
• Precursor to star-shaped π-conjugated oligomers and small molecules for organic electronics, including emissive materials for OLEDs, hole-transport layers, and organic photovoltaic donor units where the meta-linkage pattern disrupts extended conjugation to tune HOMO–LUMO gaps and emission colour.

Heterocyclic & Scaffold Assembly

Established reactant in the construction of polysubstituted aromatic and heteroaromatic frameworks used across synthetic and process chemistry programmes.

• Introduction of a 3,5-dibromophenyl unit onto nitrogen-, oxygen-, and sulfur-containing heterocycles via Suzuki coupling, installing two bromine handles directly onto a heterocyclic biaryl product for downstream derivatisation.
• Building block for the assembly of polycyclic aromatic hydrocarbons (PAHs), helicenes, and nanographene fragments through intramolecular cyclisation cascades triggered after initial cross-coupling at one or both C–Br positions.
• Applied in the preparation of sterically defined ligand architectures — the meta-bromine substituents provide vectors for appending phosphine, NHC, or pyridine donor arms to generate tripodal or pincer-type ligands for transition-metal catalysis.

Diol Recognition, Boronate Ester Formation & Sensing

The boronic acid moiety forms reversible covalent boronate esters with 1,2- and 1,3-diols under mild aqueous conditions — the electron-withdrawing dibromo substitution lowers the pKₐ of the boronic acid, enhancing diol binding affinity at physiological pH.

• Component in fluorescent and colorimetric saccharide sensors where the lowered pKₐ shifts the diol-binding equilibrium favourably at neutral pH — the two bromine substituents simultaneously serve as sites for attaching reporter fluorophores or quencher units via cross-coupling to create integrated chemosensor architectures.
• Conversion to bench-stable boronate esters (pinacol, MIDA, neopentyl glycol) used as masked boronic acid surrogates in iterative cross-coupling workflows and complex molecule assembly — the dibromo pattern is preserved throughout ester formation and regeneration.
• Applied in the preparation of boronate ester-linked dynamic covalent libraries and self-assembled macrocycles where the 1,3-dibromo substitution defines cavity geometry and host–guest selectivity.

Bioconjugation & Surface Functionalisation

Used in bioconjugation and surface chemistry strategies where the trifunctional reactivity provides simultaneous molecular-recognition and attachment capabilities.

• Coupling agent for the attachment of recognition elements to surfaces, nanoparticles, or polymer supports — the boronic acid engages diols on glycoproteins or carbohydrates while the aryl bromides are used to covalently anchor the molecule to the substrate via Pd-catalysed or Cu-catalysed coupling with surface-bound amines, alkynes, or thiols.
• Investigated as a crosslinker in boronic acid-functionalised hydrogel networks — the two aryl bromides can be pre-elaborated into polymerisable or tetherable arms, generating responsive materials whose crosslink density is modulated by pH or saccharide concentration.
• Precursor to multivalent boronic acid displays for enhanced carbohydrate binding through the cluster glycoside effect — sequential functionalisation of the two C–Br positions with additional boronic acid-bearing arms creates di- and trivalent saccharide receptors with improved avidity over the monovalent parent.