1-Naphthaleneboronic Acid | CAS 13922-41-3 | ≥98%

1-Naphthaleneboronic acid (naphthalen-1-ylboronic acid, α-naphthylboronic acid) is an arylboronic acid bearing the sterically demanding 1-naphthyl group.

May contain small amounts of the cyclic anhydride tris(1-naphthyl)boroxine. Under aqueous or basic coupling conditions the two forms re-equilibrate and the impact on yield is minor.

Applications and Reactions

• Suzuki–Miyaura cross-coupling: Installs the 1-naphthyl group onto aryl and heteroaryl halides en route to polyaromatic hydrocarbons — binaphthyls, naphthyl-anthracenes, and higher acenes — for organic semiconductors, photovoltaics, and fluorescent dyes. The C-8 peri-hydrogen, across the ring junction from boron at C-1, imposes a steric demand that sets the biaryl dihedral and rotational barrier — a handle for tuning conformation in conjugated materials.
• OLED host materials and blue molecular glasses: Builds naphthyl-anthracene intermediates for spirobenzofluorene host materials in blue OLEDs, and gives 9-(naphthalen-1-yl)anthracene, an amorphous blue-emitting molecular glass in which the bulky 1-naphthyl group suppresses crystallisation and favours glassy thin films.
• Organotrifluoroborate and ArBF₂ Lewis acids: Treatment with KHF₂ gives the bench-stable potassium 1-naphthyltrifluoroborate, a convenient precursor to 1-naphthyl boron difluoride (ArBF₂) Lewis acids.
• Fluorometric saccharide sensing: The naphthalene fluorophore reports reversible boronate-ester formation with 1,2- and 1,3-diols, enabling fluorometric detection of glucose, fructose, and related diol analytes.
• Bifunctional polymers for cellulose hydrolysis: Incorporated into polymers that bind cellulose through boronate esters with the sugar hydroxyls while co-located acid groups cleave glycosidic bonds, depolymerising biomass under milder conditions than direct acid hydrolysis.
• Serine-enzyme research: As a boronic acid it engages the active-site serine reversibly; 1-naphthaleneboronic acid is a documented AmpC β-lactamase inhibitor used in inhibitor design and mechanistic studies.

Further Reading

For boronic acids, boronic esters, protodeboronation, boroxine content, and Suzuki–Miyaura reagent selection, see NorrChemica's Lab Journal guide: Choosing Your Boron Source for Suzuki–Miyaura Coupling.