Product Overview and Chemical Properties

2-(Cyclohexylaminomethyl)-5-fluorophenylboronic acid, pinacol ester (SKU: C180715) is an arylboronate reagent featuring three distinct functional elements on a single aromatic scaffold: a pinacol-protected boronic acid group at the 1-position, a cyclohexylaminomethyl (secondary amine) group at the 2-position, and a fluorine atom at the 5-position.

The pinacol ester protection renders the boronic acid stable toward air oxidation and hydrolysis under ambient conditions compared with the free boronic acid, facilitating handling and long-term storage. The secondary amine functionality provides an additional handle for downstream elaboration via amide coupling, reductive amination, or salt formation, while the aryl fluoride can participate in nucleophilic aromatic substitution (SNAr) reactions under appropriate conditions.

This combination of features classifies C180715 as a multifunctional building block well suited to scaffold diversification strategies in drug discovery programs.

Recommended Storage and Stability Guidelines

To maintain reagent integrity and ensure reproducible results, observe the following storage guidelines for C180715:

• Atmosphere: Store under an inert atmosphere of dry nitrogen (N₂) or argon (Ar) to prevent oxidative degradation of the boronate ester and the amine functionality.
• Temperature: Keep at cool room temperature or refrigerated (2–8 °C). Avoid repeated freeze-thaw cycles if the compound is stored as a solution.
• Moisture: Boronic acid pinacol esters are susceptible to protodeboronation and hydrolysis in the presence of water. Store in a tightly sealed vial with desiccant.
• Light: Store in amber vials or in the dark to minimize photodegradation.
• Shelf life: Consult the Certificate of Analysis (CoA) for the assigned expiry date. Reanalyze purity by TLC, HPLC, or NMR if material has been stored for an extended period or if reagent performance is in question.

When weighing or transferring the compound, briefly flush the container with inert gas before resealing to minimize cumulative moisture exposure.

Protocols for Suzuki-Miyaura Cross-Coupling

The pinacol boronate group in C180715 makes it a direct participant in palladium-catalyzed Suzuki-Miyaura cross-coupling reactions with aryl or heteroaryl halides. A general protocol outline is provided below; researchers should optimize conditions for their specific substrate pairs.

General Procedure

1. Reagents: Arylboronate (C180715, 1.0–1.5 equiv), aryl halide electrophile (1.0 equiv), Pd catalyst (e.g., Pd(PPh₃)₄ or Pd(dppf)Cl₂, 2–5 mol%), base (e.g., K₂CO₃, Cs₂CO₃, or K₃PO₄, 2–3 equiv).
2. Solvent: Dioxane/H₂O (4:1 v/v), DMF/H₂O, or THF/EtOH/H₂O mixtures are commonly employed. A small amount of water is typically required for transmetalation.
3. Temperature: 80–100 °C under reflux or in a sealed vial. Microwave-assisted conditions (100–120 °C, 20–40 min) can accelerate the reaction.
4. Atmosphere: Conduct under N₂ or Ar to prevent catalyst poisoning and oxidative side reactions.
5. Workup: Cool to room temperature, dilute with EtOAc, wash with aqueous base to remove residual amine salts, dry over MgSO₄, filter, and concentrate. Purify by column chromatography.

Note on the amine group: The secondary amine in C180715 may coordinate to the palladium catalyst or interfere with some base systems. If inhibition is observed, consider temporarily protecting the amine as its Boc carbamate or HCl salt prior to coupling, then deprotecting after the reaction.

Note on the aryl fluoride: The 5-fluorine substituent is generally inert under standard Suzuki conditions but may undergo SNAr with strong nucleophiles at elevated temperatures. Monitor reactions accordingly.

Safety, Handling, and Waste Disposal

Follow standard laboratory safety practices when working with C180715. Specific precautions include:

• Personal Protective Equipment (PPE): Wear appropriate gloves (nitrile recommended), safety glasses, and a laboratory coat. Work in a well-ventilated fume hood.
• Skin and Eye Contact: Avoid contact. In case of skin contact, wash thoroughly with soap and water. In case of eye contact, irrigate with copious water and seek medical attention.
• Inhalation: Fine powder or aerosol inhalation should be avoided. Use a dust mask if handling as a dry powder in an open area.
• Boronic acid compounds: As a class, organoboron compounds have low to moderate acute toxicity, but specific toxicological data for C180715 should be confirmed in the Safety Data Sheet (SDS) available from Aladdin Scientific.
• Amine functionality: Secondary amines can act as sensitizers in some individuals. Handle with appropriate care.
• Waste Disposal: Dispose of all waste—solids, solutions, and contaminated materials—in accordance with institutional, local, and national regulations for chemical waste. Do not dispose of down the drain without proper treatment and regulatory authorization.

Always consult the current SDS for C180715 before use. The SDS is available through Aladdin Scientific's website or by contacting customer support.

Quality Control and Purity Verification

Aladdin Scientific provides a Certificate of Analysis (CoA) with each lot of C180715. Researchers are encouraged to verify purity and identity before use in critical experiments.

Recommended Analytical Methods

• ¹H NMR / ¹³C NMR / ¹¹B NMR: Nuclear magnetic resonance is the primary technique for confirming structural identity. The ¹¹B NMR chemical shift for a pinacol boronate ester typically appears around δ 30–33 ppm, consistent with a tetracoordinate or tricoordinate boron environment. The ¹H NMR should show characteristic signals for the pinacol methyl groups (typically a singlet ~1.3 ppm, 12H), the cyclohexyl ring protons, the aminomethyl CH₂, and the fluorine-substituted aryl protons.
• HPLC: Reverse-phase HPLC (C18 column) provides quantitative purity assessment. A purity of ≥95% is typically expected for research-grade material.
• TLC: A rapid qualitative check using a UV-active TLC plate can confirm the absence of major impurities.
• Mass Spectrometry (MS): ESI-MS or APCI-MS can confirm the molecular ion, noting that boronic esters can undergo in-source hydrolysis to the free boronic acid under some ionization conditions.

If analytical results deviate significantly from the CoA specifications, contact Aladdin Scientific technical support before proceeding with experiments.