Azido-PEG3-S-PEG4-t-butyl ester
CAS No.: 2055041-19-3
Cat No.: BP-500442
Purity: 98%
4.5 
Azido-PEG3-S-PEG4-t-butyl ester is a heterobifunctional polyethylene glycol (PEG) linker featuring an azide handle for bioorthogonal conjugation, a thioether (S) linkage to connect PEG segments, and a terminal acid protected as a tert-butyl ester. The PEG3–S–PEG4 architecture provides a flexible, hydrophilic spacer that can reduce steric interference between a targeting ligand and an E3 ligase recruiter in PROTAC constructs, while the azide enables efficient attachment via azide–alkyne cycloaddition or related click chemistries to introduce the linker into complex molecular scaffolds. The thioether connection offers chemical stability under typical synthetic conditions and maintains conformational freedom across the linker. In targeted protein degradation research, this linker is valuable for systematically tuning linker length, polarity, and attachment geometry to optimize ternary complex formation and degradation potency. The tert-butyl ester facilitates controlled downstream functionalization, such as conversion to a carboxylate for further coupling strategies.
Structure of 2055041-19-3
Assurance
Delivery
Support
* For research and manufacturing use only. Not for human or clinical use.
| Size | Price | Stock | Quantity |
|---|---|---|---|
| -- | $-- | In stock |
Looking for different specifications? Click to request a custom quote!
Capabilities & Facilities
- Comprehensive PROTAC Platform
- Scientific Expertise & Technical Support
- Custom Synthesis & Design Service
- Extensive Product Coverage
- Cutting-Edge Innovation
- Fast Delivery & Global Support
- 24/7 customer service
- 100% quality assurance
Popular Publications Citing BOC Sciences Products
Azido-PEG3-S-PEG4-t-butyl ester is a bifunctional polyethylene glycol-based PROTAC linker designed to combine solubility-enhancing PEG segments with a chemically addressable azide handle and a protected thiol/ester functionality for controlled conjugation. Its flexible, ether-rich scaffold supports productive ternary complex formation by improving linker reach and reducing steric constraints. The azide enables selective bioorthogonal attachment to complementary partners, while the protected group supports stepwise assembly. Detailed structural and reactivity considerations are provided below.
Structure: The linker contains an azide-bearing terminus connected through short PEG chains, incorporating multiple ether linkages that confer conformational flexibility and hydrophilicity. A sulfur-containing linkage connects PEG segments, and a tert-butyl ester provides a stable, acid-labile protecting group for subsequent functionalization.
Reactivity: PROTAC construction typically uses the azide as a click handle, most commonly via copper-free or copper-catalyzed azide–alkyne cycloaddition with an appropriately functionalized partner. The tert-butyl ester is generally introduced or maintained under neutral conditions and can be deprotected using mild acid to reveal a reactive carboxylate for coupling. Linker conjugations are commonly performed in polar organic or mixed solvent systems compatible with PEG solubility, with reaction monitoring by standard analytical methods.
* Our calculator is based on the following equation:
Concentration (start) x Volume (start) = Concentration (final) x Volume (final)
It is commonly abbreviated as: C1V1 = C2V2
Related Product Recommendations
Please contact us with any specific requirements and we will get back to you as soon as possible.
