Click-Solution

Product Information

Optimized Solvent System for CuBr in CuAAC Reactions

Click Solution is a proprietary reagent developed by baseclick that enhances the solubility, stability and catalytic performance of copper(I) bromide (CuBr), the preferred copper source for copper-catalyzed azide–alkyne cycloaddition (CuAAC) reactions in non-aqueous medium. The CuAAC reaction was the first to meet the criteria for ‘click chemistry’ and remains the most widely used click reaction today due to its reliability, efficiency and broad applicability.

Why Click Solution?

Click Solution is a carefully formulated mixture of DMSO (dimethyl sulfoxide) and t-BuOH (tert-butanol) that effectively dissolves CuBr while maintaining its catalytic integrity.

Unlike Cu(II) sulfate, which requires in situ reduction, CuBr is a direct source of the catalytically active Cu(I) species. However, CuBr is highly sensitive to air and moisture. Upon dissolution, it degrades rapidly, turning brown and losing its catalytic activity. This instability can lead to poor yields or failed reactions. Therefore, always use freshly prepared solutions.

Click Solution was specifically designed to overcome these issues if used with a ligand as TBTA:

• Improves the solubility of CuBr in organic solvents
• Stabilizes Cu(I) for optimal catalytic performance
• Minimizes oxidation, preserving the greenish color of active CuBr.
• Enables efficient reactions with hydrolysis-sensitive compounds.

The Click Solution provides an ideal environment for CuBr by balancing polarity and steric protection, thereby keeping the copper species active and soluble.

Handling and usage guidelines:

To ensure maximum efficiency and reproducibility in CuAAC reactions:

• Use freshly prepared CuBr solutions, ideally within 30 minutes of solubilization.
• Degas the Click Solution under an inert atmosphere (e.g. argon) for the best results.
• Avoid buffers containing EDTA or free thiols (e.g. DTT or mercaptoethanol), as these can chelate copper and inhibit catalysis.
• Avoid DEPC treated water as the residues can interfere with the click reaction.
• Use TBTA ligand with CuBr in the Click Solution to prevent side reactions and further stabilize Cu(I).
• Even without a protective atmosphere, quantitative yields are possible if the catalyst is used immediately.

baseclick handles its high-purity CuBr entirely under argon to prevent premature oxidation and ensure consistent catalytic activity.

Protocol support

To help researchers optimize their CuAAC reactions, baseclick provides a standard protocol for CuBr click using Click Solution. This protocol serves as a starting point and may require adjustment based on:

• Concentration of reactants
• Nature of azide and alkyne reagents

For best results, adapt the conditions to your specific experimental setup.