3-Furanboronic Acid | CAS 55552-70-0 | ≥97%

Suzuki–Miyaura cross-coupling reactions: 3-Furanboronic acid is a widely used heteroaryl boronic acid building block for palladium-catalysed Suzuki–Miyaura cross-coupling reactions. It introduces a furan-3-yl motif into molecular frameworks via carbon–carbon bond formation with aryl and heteroaryl halides. The compound shows excellent reactivity with aryl chlorides in aqueous n-butanol solvent systems at catalyst loadings as low as 0.1–1 mol % Pd, achieving near-quantitative yields. Aqueous catalysis conditions have been shown to be more efficient for heteroaromatic substrates than anhydrous Suzuki coupling.

Heteroaryl–heteroaryl coupling: 3-Furanboronic acid couples efficiently with a range of heteroaryl halides including 3-bromothiophene, 2,3-bromopyridine, and 3-bromoquinoline, without catalyst poisoning from heteroatom coordination to the palladium centre. This tolerance makes it a preferred coupling partner for constructing mixed heterobiaryl systems that are common structural motifs in bioactive compounds.

Synthesis of fused heterocyclic scaffolds: The compound has been employed in the synthesis of furo[2,3-c]quinolines through Pd(0)-catalysed cross-coupling of 2-formyl-3-furanboronic acid derivatives with functionalised haloarenes. It is also used in the preparation of 2,5-diarylfurans and related heteropentalene systems via sequential bromination and Suzuki coupling strategies.

Star-shaped and extended conjugated systems: 3-Furanboronic acid serves as a building block for the preparation of C₃-symmetric star-shaped molecules containing furan units, constructed through trimerisation of acetyl aromatic precursors followed by Suzuki–Miyaura cross-coupling. These architectures are investigated in materials science for their optoelectronic and self-assembly properties.

Electrochemical biosensor and biofuel cell fabrication: Poly(furan-3-boronic acid) has been prepared and combined with chitosan, uricase, Pd nanoparticles, and multiwalled carbon nanotubes on gold electrodes to fabricate amperometric biosensors and biofuel cells for uric acid detection. The boronic acid functionality provides diol-binding capability that anchors the biorecognition layer.

General boronate ester chemistry: As an arylboronic acid, 3-furanboronic acid forms reversible cyclic boronate esters with cis-1,2- and 1,3-diols in aqueous solution. The electron-rich furan ring influences the pKa and binding kinetics of the boronic acid group, which is relevant to the design of saccharide-responsive materials and diol-selective separation media.