Fmoc-N-amido-PEG5-acetic acid

Name: Fmoc-N-amido-PEG5-acetic acid
Brand: BOC Sciences
Rating: 5 (1 reviews)

CAS No.: 635287-26-2

Cat No.: BP-500543

Purity: ≥95% 4.5

Fmoc-N-amido-PEG5-acetic acid is a polyethylene glycol (PEG) linker building block bearing an N-terminal Fmoc-protected amide and a terminal acetic acid functionality, enabling controlled conjugation and solid-phase or solution-phase assembly of PROTAC constructs. Structurally, it provides a flexible, hydrophilic chain length that can spatially separate a warhead (target-binding ligand) from an E3-recruiting moiety, helping to reduce steric clashes and improve productive ternary complex formation. The amide linkage allows stable coupling to neighboring carboxyl- or amine-bearing components via standard peptide coupling chemistries, while the Fmoc group supports orthogonal deprotection and stepwise synthesis for multi-component degraders. In targeted protein degradation research, such PEG-based linkers are widely used to tune linker flexibility, solubility, and membrane/aggregation behavior, facilitating systematic structure–activity relationship studies and optimization of degradation potency and selectivity.

Structure of 635287-26-2

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Category

PROTAC Linker

Molecular Formula

C27H35NO9

Molecular Weight

517.57

Related CAS

675606-79-8 (polymer)

Appearance

Pale Yellow or Colorless Oily Liquid

* For research and manufacturing use only. Not for human or clinical use.

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Comprehensive PROTAC Platform
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Popular Publications Citing BOC Sciences Products

Purity

≥95%

Solubility

Soluble in DMSO (10 mm)

Appearance

Pale Yellow or Colorless Oily Liquid

Storage

Store at 2-8°C

Shipping

Room temperature

IUPACName

2-[2-[2-[2-[2-[2-(9H-fluoren-9-ylmethoxycarbonylamino)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]acetic acid

Synonyms

Fmoc-NH-PEG5-CH2COOH; Fmoc-NH-5(ethylene glycol)-acetic acid; Fmoc-PEG5-acetic acid; 1-(9H-Fluoren-9-yl)-3-oxo-2,7,10,13,16,19-hexaoxa-4-azahenicosan-21-oic acid; 17-[(9-Fluorenylmethoxycarbonyl)amino]-3,6,9,12,15-pentaoxaheptadecanoic acid; 5,8,11,14,17-Pentaoxa-2-azanonadecanedioic acid 1-(9H-fluoren-9-ylmethyl) ester; 2,7,10,13,16,19-Hexaoxa-4-azaheneicosan-21-oic acid, 1-(9H-fluoren-9-yl)-3-oxo-

Boiling Point

704.3±60.0°C (Predicted)

Density

1.224±0.06 g/cm3 (Predicted)

InChI Key

LNIFRTLAPAPKAG-UHFFFAOYSA-N

InChI

InChI=1S/C27H35NO9/c29-26(30)20-36-18-17-35-16-15-34-14-13-33-12-11-32-10-9-28-27(31)37-19-25-23-7-3-1-5-21(23)22-6-2-4-8-24(22)25/h1-8,25H,9-20H2,(H,28,31)(H,29,30)

SMILES

C1=CC=C2C(=C1)C(C3=CC=CC=C32)COC(=O)NCCOCCOCCOCCOCCOCC(=O)O

1. Acidity characterization of heterogeneous catalysts by solid-state NMR spectroscopy using probe molecules

Anmin Zheng, Shang-Bin Liu, Feng Deng Solid State Nucl Magn Reson. 2013 Oct-Nov;55-56:12-27. doi: 10.1016/j.ssnmr.2013.09.001. Epub 2013 Sep 20.

Characterization of the surface acidic properties of solid acid catalysts is a key issue in heterogeneous catalysis. Important acid features of solid acids, such as their type (Brønsted vs. Lewis acid), distribution and accessibility (internal vs. external sites), concentration (amount), and strength of acid sites are crucial factors dictating their reactivity and selectivity. This short review provides information on different solid-state NMR techniques used for acidity characterization of solid acid catalysts. In particular, different approaches using probe molecules containing a specific nucleus of interest, such as pyridine-d5, 2-(13)C-acetone, trimethylphosphine, and trimethylphosphine oxide, are compared. Incorporation of valuable information (such as the adsorption structure, deprotonation energy, and NMR parameters) from density functional theory (DFT) calculations can yield explicit correlations between the chemical shift of adsorbed probe molecules and the intrinsic acid strength of solid acids. Methods that combine experimental NMR data with DFT calculations can therefore provide both qualitative and quantitative information on acid sites.

2. The Stephan Curve revisited

William H Bowen Odontology. 2013 Jan;101(1):2-8. doi: 10.1007/s10266-012-0092-z. Epub 2012 Dec 6.

The Stephan Curve has played a dominant role in caries research over the past several decades. What is so remarkable about the Stephan Curve is the plethora of interactions it illustrates and yet acid production remains the dominant focus. Using sophisticated technology, it is possible to measure pH changes in plaque; however, these observations may carry a false sense of accuracy. Recent observations have shown that there may be multiple pH values within the plaque matrix, thus emphasizing the importance of the milieu within which acid is formed. Although acid production is indeed the immediate proximate cause of tooth dissolution, the influence of alkali production within plaque has received relative scant attention. Excessive reliance on Stephan Curve leads to describing foods as "safe" if they do not lower the pH below the so-called "critical pH" at which point it is postulated enamel dissolves. Acid production is just one of many biological processes that occur within plaque when exposed to sugar. Exploration of methods to enhance alkali production could produce rich research dividends.

3. Atroposelective Synthesis of 1,1'-Bipyrroles Bearing a Chiral N-N Axis: Chiral Phosphoric Acid Catalysis with Lewis Acid Induced Enantiodivergence

Yaru Gao, Luo-Yu Wang, Tao Zhang, Bin-Miao Yang, Yu Zhao Angew Chem Int Ed Engl. 2022 Apr 11;61(16):e202200371. doi: 10.1002/anie.202200371. Epub 2022 Feb 24.

We present herein a highly efficient atroposelective synthesis of axially chiral 1,1'-bipyrroles bearing an N-N linkage from simple hydrazine and 1,4-diones. Further product derivatizations led to axially chiral bifunctional compounds with high potential in asymmetric catalysis. For this chrial phosphoric acid (CPA)-catalyzed double Paal-Knorr reaction, an intriguing Fe(OTf)3 -induced enantiodivergence was also observed.

Fmoc-N-amido-PEG5-acetic acid is a polyethylene glycol (PEG)-based PROTAC linker building block designed to provide solubility, conformational flexibility, and a chemically addressable handle for modular assembly. Its Fmoc-protected amide functionality supports stepwise synthesis, while the PEG spacer and acetic acid terminus enable robust conjugation strategies commonly used in targeted protein degradation workflows. The following sections describe its structure and practical reactivity considerations in detail.

Structure: The molecule contains an Fmoc-protected amide linked to a PEG-based spacer and an acetic acid functionality. It features stable amide and ether linkages, aromatic carbamate protection, and a terminal carboxylic acid. These elements collectively impart hydrophilicity and conformational flexibility typical of PEG linkers.

Reactivity: Use the carboxylic acid and amide-compatible chemistry to form PROTAC conjugates via standard coupling reactions, typically employing carbodiimide-based activators with auxiliary base in polar aprotic solvents. The Fmoc group can be removed under controlled base conditions to reveal an amine for subsequent amide bond formation. Reaction design should account for PEG solubility and minimize conditions that cause premature deprotection.

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* 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