Thalidomide-O-PEG4-Azide | CAS 2380318-57-8

Thalidomide-O-PEG4-Azide is a PEGylated thalidomide-derived azide building block designed for copper-free and/or copper-mediated azide–alkyne click chemistry workflows. The reagent combines a bioactive, thalidomide-based scaffold with a short, flexible PEG4 spacer and a terminal azide handle, enabling modular attachment of diverse functional groups to thalidomide-like ligands. In research and materials settings, this structure is commonly used to prepare conjugatable probes, immobilized affinity reagents, and imaging/assay components that require stable, site-selective click attachment.

1. Target Ligand Conjugation

Thalidomide-O-PEG4-Azide is widely used as a conjugation-ready ligand intermediate for building thalidomide-inspired affinity constructs with defined attachment points. Researchers incorporate the azide handle to couple the scaffold to alkyne-bearing reporters, linkers, or surface-reactive groups, producing modular conjugates for binding studies, cell-surface labeling experiments, and comparative structure–activity mapping in chemical biology. The PEG4 spacer helps maintain accessibility of the ligand during downstream conjugation and assay formatting, which is particularly valuable when preparing multicomponent probes that include bulky dyes, affinity tags, or polymer segments.

2. Molecular Imaging Probes

Thalidomide-O-PEG4-Azide serves as an azide-functional platform for generating molecular imaging reagents in preclinical research workflows focused on probe optimization and labeling strategies. By clicking to alkyne-functional fluorophores or imaging moieties, teams can create ligand–reporter conjugates with controlled stoichiometry and a consistent tether length, supporting reproducible probe behavior across labeling batches. The PEG4 segment is commonly leveraged to reduce steric constraints around the thalidomide scaffold, improving practical conjugate design for microscopy, flow-based readouts, and imaging reagent screening in molecular imaging and diagnostic-reagent development.

3. Surface Immobilized Affinity Materials

Thalidomide-O-PEG4-Azide is used to prepare surface-immobilized affinity materials where a thalidomide-like ligand must be presented on a solid support with a defined, flexible linker. In biomaterials and assay development, the azide group enables click attachment to alkyne-functionalized surfaces such as modified glass, polymer films, or microarray platforms, allowing researchers to construct ligand-coated materials for binding assays and capture formats. The PEG4 spacer supports ligand accessibility at the interface, which is important for developing reproducible immobilized reagents used in screening workflows, ligand characterization, and platform prototyping.

4. Diagnostic Reagent Building Blocks

Thalidomide-O-PEG4-Azide is a practical building block for assembling diagnostic-reagent components that require modular conjugation of a thalidomide-derived ligand to assay-compatible detection chemistries. Teams often use the azide handle to click to alkyne-bearing enzyme labels, chemiluminescent tags, or affinity handles, enabling the rapid generation of reagent panels for assay optimization and reagent compatibility testing. The PEG4 tether provides a convenient design element for balancing signal presentation and steric accessibility, which helps streamline development of multivalent or modular assay reagents used in research diagnostics and analytical chemistry applications.