Potassium (5-Bromothiophen-2-yl)trifluoroborate | CAS 1239370-98-9 | ≥98%

Potassium (5-Bromothiophen-2-yl)trifluoroborate is a bifunctional heteroaryltrifluoroborate salt combining a thiophen-2-yltrifluoroborate coupling handle with a retained 5-bromo substituent.

Applications and Reactions

• Suzuki–Miyaura cross-coupling: the trifluoroborate group couples with aryl, heteroaryl, or alkenyl electrophiles under Pd-catalysed aqueous-base conditions to install a 5-bromothiophen-2-yl unit.
• Bifunctional C–B/C–Br handle: the C–BF3K and C–Br sites can be addressed sequentially under matched cross-coupling conditions to access unsymmetrical 2,5-disubstituted thiophenes.
• Second-site diversification: after initial Suzuki coupling, the retained bromide can support further C–C, C–N, or carbonylative transformations at the thiophene C5 position.
• Conjugated materials intermediate: provides a prefunctionalised thiophene unit for π-conjugated oligomers, donor–acceptor scaffolds, chromophores, and organic semiconductor intermediates.
• Polymer-building-block use: bifunctional thiophene monomers of this type are suited to stepwise or polycondensation approaches where regiochemical placement of thiophene units matters.
• Pharmaceutical and agrochemical scaffolds: enables modular synthesis of 2,5-disubstituted thiophene intermediates for medicinal-chemistry and agrochemical research libraries.

Further Reading

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