Potassium (3,4-Dichlorophenyl)trifluoroborate | CAS 850623-68-6 | ≥98%

Suzuki-Miyaura Cross-Coupling for Dichlorinated Biaryls

• Potassium (3,4-dichlorophenyl)trifluoroborate is an effective nucleophilic coupling partner in palladium-catalysed Suzuki-Miyaura reactions for the construction of 3,4-dichlorobiaryl scaffolds. The trifluoroborate salt undergoes controlled hydrolysis under aqueous basic conditions, releasing the active boronate species at a rate that suppresses protodeboronation and homocoupling side reactions. Standard catalytic systems including Pd(PPh₃)₄, Pd(dppf)Cl₂, and Pd(OAc)₂ with SPhos or XPhos ligands are effective, and coupling proceeds with a broad range of aryl bromides, chlorides, triflates, and tosylates to deliver the desired dichlorobiaryl products in high yield.
• Molander and Biolatto (J. Org. Chem. 2003, 68, 4302) established the general utility of potassium aryltrifluoroborates in Suzuki-Miyaura coupling, demonstrating their compatibility with electron-poor and halogenated aryl substrates.

3,4-Dichlorophenyl Motif in Pharmaceutical Research

• The 3,4-dichlorophenyl group is one of the most widely encountered halogenated aryl substituents in bioactive molecules, appearing in numerous marketed pharmaceuticals and clinical candidates across therapeutic areas including oncology, infectious disease, and central nervous system disorders. The adjacent chlorine atoms provide a combination of steric and electronic effects that enhance binding affinity, modulate lipophilicity for improved membrane permeability, and block metabolically vulnerable positions on the aromatic ring. Potassium (3,4-dichlorophenyl)trifluoroborate enables reliable and reproducible installation of this pharmacophoric element via cross-coupling, with the bench-stable crystalline salt format being ideally suited for parallel library synthesis and high-throughput screening campaigns.

Rhodium-Catalysed Conjugate Addition

• Potassium (3,4-dichlorophenyl)trifluoroborate participates in rhodium-catalysed 1,4-conjugate additions to α,β-unsaturated ketones, esters, and amides. Using [Rh(cod)OH]₂ or Rh(acac)(CO)₂ with chiral bisphosphine ligands, the 3,4-dichlorophenyl group is transferred to the β-position of Michael acceptors with high enantioselectivity. The controlled nucleophilicity of the trifluoroborate salt compared to the free boronic acid provides cleaner reaction profiles and minimises the formation of protodeboronation by-products that can complicate purification and reduce isolated yields.
• Batey and Quach (Org. Lett. 2003, 5, 4397) established potassium organotrifluoroborates as effective substrates for rhodium-catalysed additions to carbonyl compounds and conjugate acceptors.

Chan-Lam Coupling and C–Heteroatom Bond Formation

• In copper-mediated Chan-Lam coupling reactions, potassium (3,4-dichlorophenyl)trifluoroborate transfers the dichloroaryl group to nitrogen and oxygen nucleophiles under mild conditions at room temperature in open air. This transformation provides practical access to N-(3,4-dichlorophenyl) amines, amides, and heterocycles as well as diaryl ethers bearing the dichlorophenyl motif. These products are valuable intermediates in agrochemical synthesis, where the 3,4-dichloroaniline substructure is a core element of several herbicide and fungicide classes.

Advantages of Trifluoroborate Salts over Boronic Acids

• Potassium aryltrifluoroborates offer significant practical advantages over the corresponding boronic acids for both discovery and process chemistry. The crystalline salts have precisely defined molecular weights and stoichiometries, eliminating the variable boroxine and hydrate content that complicates accurate weighing of boronic acids. They are indefinitely stable under ambient storage conditions without refrigeration or inert atmosphere, simplifying inventory management and reducing waste from degraded reagents. In the case of dichlorophenyl derivatives, the trifluoroborate salt avoids the moderate instability of 3,4-dichlorophenylboronic acid, which can undergo slow protodeboronation during prolonged storage.
• Darses and Genet (Chem. Rev. 2008, 108, 288) provide a comprehensive review of organotrifluoroborate chemistry covering preparation methods, stability, and applications across the full spectrum of transition metal-catalysed transformations.