Click Reaction In Water Research Articles

Direct access to stabilized CuI using cuttlebone as a natural-reducing support for efficient CuAAC click reactions in water

Cuttlebone@CuCl2 as a highly active, versatile, and green heterogeneous catalyst was investigated for the efficient preparation of 1,4-disubstituted 1,2,3-triazoles through the one-pot Huisgen 1,3-dipolar cycloaddition reaction in water.

Effective ascorbate-free and photolatent click reactions in water using a photoreducible copper(II)-ethylenediamine precatalyst

The search for copper catalysts able to perform effectively click reactions in water in the absence of sodium ascorbate is an active area of current research with strong potential for applications in bioconjugation. The water-soluble and photoreducible copper(II)–EDA (EDA = ethylenediamine) complex 1, which has two 4-benzoylbenzoates acting as both counterion and photosensitizer, has been synthesized and characterized by different techniques including single crystal X-ray diffraction. Highly efficient photoreduction was demonstrated when solutions of 1 in hydrogen atom donating solvents, such as THF or MeOH, were exposed to UVA radiation (350–400 nm) provided by a low pressure mercury lamp (type TLC = thin-layer chromatography, 365 nm), or by a 23 W fluorescent bulb, or by ambient/sunlight. In water, a much poorer hydrogen atom donating solvent, the photoreduction of 1 proved inefficient. Interestingly, EPR studies revealed that complex 1 could nonetheless be effectively photoreduced in water when alkynes were present in solution. The catalytic activity of 1 for click reactions involving a range of water-soluble alkynes and azides, in particular saccharides, was tested under various illumination conditions. Complex 1 was found to exhibit a photolatent character, the photogenerated copper(I) being very reactive. On irradiating aqueous reaction mixtures containing 1 mol % of 1 at 365 nm (TLC lamp) for 1 h, click reactions were shown to proceed to full conversion.

In situ prepared copper nanoparticles on modified KIT-5 as an efficient recyclable catalyst and its applications in click reactions in water

A novel heterogeneous copper nano catalyst supported on modified silica mesopore KIT-5 was successfully prepared. The 3-aminopropyltriethoxysilane (APTES) on KIT-5 was coordinated with copper(I) and accurately characterized. In addition a comparative survey on the metal-ligand interactions in the syntheses of catalyst in two different solvents via density functional theory calculations was performed. A one-pot procedure for syntheses of 1,4-disubstituted 1,2,3-triazole derivatives via a three-component reaction between terminal alkynes, alkyl halides, and sodium azide, namely click reaction in the presences of 3mol% nanoparticles copper/APTES-KIT-5 (Cu/AK) as a catalyst was developed to give the products in good to excellent yields. This catalyst showed high catalytic activity in water as a “green” solvent. This reaction was performed under open air conditions and required no special reaction conditions and chromatographic separation for purification.

In situ prepared CuI nanoparticles on modified poly(styrene-co-maleic anhydride): an efficient and recyclable catalyst for the azide–alkyne click reaction in water

A facile, high-yielding and straightforward methodology for the copper-catalyzed synthesis of 1,4-disubstituted 1,2,3-triazoles in water, using in situ prepared copper nanoparticles (NPs) on modified poly(styrene-co-maleic anhydride) [SMA] catalyst, is reported. The polymer support was easily prepared from the reaction of SMA with 4-aminopyridine and subsequently underwent reaction with CuI NPs. The catalyst was applied for the preparation of triazoles under air, followed by chromatographic separation of the products. The polymer-supported catalyst not only showed high catalytic activity but also showed high 1,4-regioselectivity for the [3 + 2] Huisgen cycloaddition in water as solvent. The products were obtained in good to excellent yields in all cases. The catalyst can be used without pre-activation and reloaded for at least five runs without significant decrease in its activity. The catalyst was characterized by SEM, energy dispersive spectroscopy analysis of X-rays, and inductively coupled plasma.

ChemInform Abstract: Efficient Click‐Polymer‐Stabilized Palladium Nanoparticle Catalysts for Suzuki—Miyaura Reactions of Bromoarenes and Reduction of 4‐Nitrophenol in Aqueous Solvents.

AbstractPalladium nanoparticles (size=1.6.+‐.0.3 nm) used for the Suzuki—Miyaura coupling of aryl bromides with phenyl boronic acid are stabilized by polyethylene glycol containing triazolyl rings synthesized by click reaction in water.

Efficient Click‐Polymer‐Stabilized Palladium Nanoparticle Catalysts for Suzuki–Miyaura Reactions of Bromoarenes and Reduction of 4‐Nitrophenol in Aqueous Solvents

AbstractPalladium nanoparticles (size=1.6±0.3 nm) stabilized by a polyethylene glycol containing triazolyl rings, synthesized by click reaction in water, are efficient catalysts for the Suzuki–Miyaura coupling of bromoarenes in aqueous ethanol and the borohydride reduction of 4‐nitrophenol in water. Turnover numbers (TONs) reach 99,000 and turnover frequencies (TOFs) are up to 198,000 h−1 for the CC cross coupling reactions in water/ethanol.magnified image

Porous copper catalyzed click reaction in water

1,2,3-Triazoles were synthesized in water using a cheaper, simple and easily recyclable heterogeneous porous Cu catalyst via one-pot multi component reaction. The catalyst can be recycled five times without significant loss of its catalytic activity.

Magnetic copper–iron nanoparticles as simple heterogeneous catalysts for the azide–alkyne click reaction in water

The development of a novel bimetallic copper–iron nanoparticle synthesis provides a recoverable heterogeneous catalyst for the azide–alkyne “click” reaction in water. The nanoparticles catalyze the production of a diverse range of triazoles, while separation and reuse proved to be easy.

Bioorthogonal dual functionalization of self-assembling peptide fibers

The ability to modify peptide- and protein-based biomaterials selectively under mild conditions and in aqueous buffers is essential to the development of certain areas of bionanotechnology, tissue engineering and synthetic biology. Here we show that Self-Assembling peptide Fibers (SAFs) can incorporate multiple modified peptides non-covalently, stoichiometrically and without disrupting their structure or stability. The modified peptides contain groups suitable for post-assembly click reactions in water, namely azides and alkenes. Labeling of these groups is achieved using the orthogonal Cu(I)-catalyzed azide-alkyne and photoinitiated thiol-ene reactions, respectively. Functionalization is demonstrated through the conjugation of biotin followed by streptavidin-nanogold particles, or rhodamine, and visualized by electron and light microscopy, respectively. This has been shown for fibers harboring either or both of the modified peptides. Furthermore, the amounts of each modified peptide in the fibers can be varied with concomitant changes in decoration. This approach allows the design and assembly of fibers with multiple functional components, paving the way for the development of multi-component functionalized systems.

Stabilized Copper(I) Oxide Nanoparticles Catalyze Azide‐Alkyne Click Reactions in Water

AbstractA novel form of polyvinylpyrrolidone (PVP) coated copper(I) oxide nanoparticle (Cu2O‐NP) was prepared and used to catalyze azide‐alkyne click reactions in water under aerobic conditions. The nanoparticles were well dispersed in aqueous solutions and have a size of 20±10 nm, as determined by transmission electron microscope (TEM). Inductively coupled plasma (ICP), X‐ray powder diffraction (XRD), and X‐ray photoelectron spectroscopy (XPS) analyses demonstrated that the main content of Cu2O‐NP is copper(I). The cytotoxicity of it was evaluated by an in vitro 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay and its catalytic efficiency for azide‐alkyne click reactions was studied in water and organic solvents at physiological temperatures. Our results indicate that Cu2O‐NP is more efficient in catalytic reactions in water for both aliphatic and aromatic azides and alkynes and less toxic than the commonly used CuSO4/reductant catalyst systems.

Characterisation of N-vinyl-2-pyrrolidone-based hydrogels prepared by a Diels–Alder click reaction in water

N-vinyl-2-pyrrolidone-based hydrogels were prepared by the Diels–Alder reaction in water for the first time. Copolymers of N-vinyl-2-pyrrolidone(VP) and furfuryl methacrylate(FM) were synthesised by free radical polymerisation in toluene at 70 °C by using 2,2′-azobisisobutyronltrile as an initiator. Polymeric dienophile (PEG–AMI) was prepared from N-alaninyl maleimide (AMI) and poly(ethylene glycol) (PEG) by using N, N′-dicyclohexylcarbodiimide (DCC) as a dehydrating agent. The prepared dienes and dienophile were then dissolved in water and mixed, leading to gelation via Diels–Alder reaction after some time. The gelation times of different copolymers and PEG–AMI in different solvents and at different temperatures were measured by the vial inversion method, and the swelling behaviour of dried hydrogels was studied using a general gravimetric method. The gelation time was shorter in water than in organic solvents, and the gelation time decreased with the increase of temperature and FM content in copolymers. Conversely, the swelling ratios increased with the decrease of temperature and FM content in the copolymers. Disassembly experiments suggested that N, N-dimethylformamide (DMF) could accelerate the retro-DA reaction.

A versatile method for the preparation of conjugates of peptides with DNA/PNA/analog by employing chemo-selective click reaction in water

The specific 1,3 dipolar Hüisgen cycloaddition reaction known as ‘click-reaction’ between azide and alkyne groups is employed for the synthesis of peptide–oligonucleotide conjugates. The peptide nucleic acids (PNA)/DNA and peptides may be appended either by azide or alkyne groups. The cycloaddition reaction between the azide and alkyne appended substrates allows the synthesis of the desired conjugates in high purity and yields irrespective of the sequence and functional groups on either of the two substrates. The versatile approach could also be employed to generate the conjugates of peptides with thioacetamido nucleic acid (TANA) analog. The click reaction is catalyzed by Cu (I) in either water or in organic medium. In water, ∼3-fold excess of the peptide-alkyne/azide drives the reaction to completion in 2 h with no side products.