Synthesis of 1--Glycosylthiomethyl-1,2,3-triazoles.
M.; Mantovani, G.; Ladmiral, V., Peptide glycopolymer conjugates via living radical polymerization and click chemistry.
Synthesis of Propargyl-Terminated Heterobifunctional …
Preparation, Characterization, and Application of Poly(vinyl alcohol)-graft-Poly(ethylene glycol) Resins: Novel Polymer Matrices for Solid-Phase Synthesis.
A crucial requirement while working with homobifunctional OEGs is the ability to differentiate the reactivity of two chemically equivalent terminal diols. Many previous studies addressed the desymmetrization of homofunctional OEGs using the Williamson ether synthesis,, in which the benzyl and p-methoxybenzyl ether groups were most commonly used for the monoprotection of symmetrical OEGs. However, reports on the synthesis of alkyne-terminated heterobifunctionalized OEGs are rare. In one such report, Gill et al. synthesized propargyl-PEG6-OH in 54% yield from hexa(ethylene glycol) (OH-PEG6-OH) using equimolar amounts of sodium hydride (NaH) and propargyl bromide. In our case, tetra(ethylene glycol) (OH-PEG4-OH, 1a), hexa(ethylene glycol) (OH-PEG6-OH, 1b) and octa(ethylene glycol) (OH-PEG8-OH, 1c) were used to synthesize 2a-c in moderate yields (37-69%) using a similar procedure. In contrast to traditional monoalkylations, propargyl bromide was added to 1b and 1c at room temperature to prevent the solidification of the starting materials at 0°C in THF. Minor amounts (~5%) of dialkylated OEGs were also formed, but they were easily separated by silica gel column chromatography. Unreacted starting OEGs (1a-c) were recovered from the aqueous layer during the workup procedures. The 1H NMR spectra of OEGs 2a-c exhibited a very characteristic triplet for one proton at ~δ 2.4 ppm assigned to the propargyl group.
Synthesis of Propargyl-Terminated Heterobifunctional Poly(ethylene ..
1. Hutanu D, Frishberg MD, Guo L, Darie CC (2014) Recent Applications of Polyethylene Glycols (PEGs) and PEG Derivatives. Mod Chem appl 2:132. . Read about select applications of JenKem® PEGs in the medical device, drug development, and diagnostics areas, including drug delivery, wound healing, cell culture models, and tissue regeneration.
Founded in 2004 by recognized experts in PEG synthesis and PEGylation, JenKem Technology specializes exclusively in the development and manufacturing of high quality polyethylene glycol (PEG) products and derivatives, and related custom polymer synthesis and PEGylation services. JenKem Technology is ISO 9001 and ISO 13485 certified, and adheres to ICH Q7A guidelines for GMP manufacture. The production of JenKem® PEGs is back-integrated to on-site manufacturing from ethylene oxide, enabling facile traceability for GMP regulated customers. JenKem Technology caters to the PEGylation needs of the pharmaceutical, biotechnology, medical device and diagnostics, and emerging chemical specialty markets, from laboratory scale through large commercial scale.
Selective Synthesis of Heterobifunctional Poly(ethylene glycol) ..
A novel synthetic route to heterobifunctional poly(ethylene glycol) (PEG) derivatives containing both mercapto and acetal terminal groups was established in this study using anionic ring opening polymerization of ethylene oxide (EO) using potassium 3,3-diethoxypropanolate (PDP) as the initiator, followed by the successive conversion of the end-alkoxide group to a methanesulfonic group, and then to an ethyldithiocarbonate moiety. Molecular functionalities of the acetal and the mercapto terminal groups of the heterotelechelic PEG (acetal-PEG-SH) thus prepared were confirmed to 1.00 and 0.85, respectively, indicating that the reaction proceeds almost quantitatively. The obtained acetal-PEG-SH products, including 2-pyridyldithio derivatives, have a promising utility for bioconjugation in the fields of medicine and biology.
New azido-terminated heterobifunctional poly(ethylene glycol) (PEG) derivatives having primary amine and carboxyl end groups, (Azide-PEG-NH2 and Azide-PEG-COOH, respectively) were synthesized with high efficiency. An α-allyl-ω-hydroxyl PEG was prepared as the first step to Azide-PEG-X (X = NH2 and COOH) through the ring-opening polymerization of ethylene oxide (EO) with allyl alcohol as an initiator, followed by two-step modification of the hydroxyl end to an azido group. To introduce primary amino or carboxyl functional groups, amination and carboxylation reactions of the allyl terminal ends was then conducted by a radical addition of thiol compounds. Molecular functionalities of both ends of the PEG derivatives thus prepared were characterized by 1H, 13C NMR, and MALDI-TOF MS spectra, validating that the reaction proceeded quantitatively. The terminal azido functionality is available to conjugate various ligands with an alkyne group through the 1,3-dipolar cycloaddition reaction condition (“click chemistry”).
glycol) Synthesis of Propargyl-Terminated ..
(the modification of molecules with polyethylene glycol ..
A Facile Synthesis of Azido-Terminated Heterobifunctional Poly(ethylene glycol) ..
Scheme 2—structure of a heterobifunctional polyethylene glycol ..
Synthesis of heterobifunctional polyethylene glycols: Polymerization from ..
for the Synthesis of Polyethylene Glycol ..
A Facile Synthesis of Azido-Terminated Heterobifunctional Poly(ethylene glycol)s for “Click” Conjugation
One preferred example of a polyethers is polyethylene glycol
Bromotris(triphenylphosphine) copper(I) CuBr(PPh3)3, N,N-iisopropylethylamine (DIPEA), 4-dimethylaminopyridine (DMAP), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC), copper(II) sulfate (CuSO4), (+)-sodium L-ascorbate, magnesium sulfate MgSO4, deuterated solvents, dichloromethane (DCM), and other solvents were purchased from Acros (Morris Plains, NJ). 20(S)-Camptothecin (95%) (CPT) and silica gel 60 (40–63 μm, 230–400 mesh) were purchased from Sigma-Aldrich (St. Louis, MO). Cy5.5 azide was purchased from Lumiprobe (Hallandale Beach, FL). 6-Azidohexanoic acid (AHA) was synthesized by us following a reported method with slight modifications. Methoxypolyethylene glycol azide (mPEG-azide) was synthesized from mPEG 750 gmol−1. Dialysis tubing, snake skin MWCO 3500, was obtained from Thermo Fisher Scientific (Pittsburg, PA).
to the synthesis of propargyl-capped ..
Short-chain PEGs or oligo(ethylene glycol)s (OEGs) have found widespread use as spacers or linkers for targeted drug delivery systems because they are inexpensive, water soluble, biostable, and available in a wide range of molecular weight distributions., A targeted drug delivery system requires two distinct reactive termini on the linker, one for attaching the therapeutic payload, and the other for attaching a targeting ligand (e.g., peptides, proteins, or antibodies). Most commercially available OEGs are monofunctional, containing only a single reactive hydroxyl, amine, thiol, aldehyde or carboxylic acid terminal group or activated variants of these. However, few heterobifunctional OEGs are commercially available containing two different reactive groups at the distal ends. Therefore, there is a need to develop efficient and diverse methods to synthesize heterobifunctionalized OEGs with highly reactive end groups (). These termini must additionally be reactive under mild, aqueous reaction conditions to permit conjugation of delicate peptide and antibody targeting moieties.
Synthesis of heterobifunctional polyethylene ..
The OEGs produced by these various methods make them useful for azide-alkyne click reactions. An example of this utility is demonstrated in high-yield production of discrete long-chain PEGs. Although expensive, PEGs having 6 or 8 ethylene glycol units are commercially available in 85-95% purity. However, long-chain PEGs (e.g., with 16 or 24 ethylene glycol units), are extremely difficult to acquire and are usually of low purity. We overcame this barrier by developing a very simple and efficient methodology to synthesize discrete PEG16 (18) and PEG24 derivatives (19), in high yield by employing a Cu(I)-catalyzed azide-alkyne click reaction (). The PEG16 derivative 18 was synthesized in 98% yield by reacting 1.0 eq of alkyne-terminated OEG 2c with 1.0 eq azide-functionalized OEG 11c. The PEG24 derivative 19 was synthesized by reacting 2.0 eq of alkyne-terminated OEG 2c with 1.0 eq of diazide 12c in 96% yield. PEG products 18 and 19 were characterized using 1H, 13C NMR and HRMS. The 1H NMR spectra of both compounds showed a characteristic singlet at ~ δ 7.6 ppm that was assigned to the -CH- of the triazole ring formed via the azide-alkyne [3+2] dipolar cycloaddition reaction.
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