Search results for "Click chemistry"

2013

The folate receptor (FR) is a well-established target for tumor imaging and therapy. To date, only a few 18 F-folate conjugates via 18 F-prosthetic group labeling for positron emission tomography (PET) imaging have been developed. To some extent, they all lack the optimal balance between efficient radiochemistry and favorable in vivo characteristics. A new clickable olate precursor was synthesized by regioselective coupling of folic acid to 11-azido-3,6,9-trioxaundecan-1-amine at the γ-position of the glutamic acid residue. The non-radioactive reference compound was synthesized via copper-catalyzed azide-alkyne cycloaddition of 3-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)prop-1-yne and γ-(11-azid…

Innentitelbild: Strain-Promoted Cycloaddition of Cyclopropenes with o -Quinones: A Rapid Click Reaction (Angew. Chem. 32/2018)

2018

Inside Cover: Strain-Promoted Cycloaddition of Cyclopropenes with o -Quinones: A Rapid Click Reaction (Angew. Chem. Int. Ed. 32/2018)

2018

Towards a fully synthetic MUC1-based anticancer vaccine: efficient conjugation of glycopeptides with mono-, di-, and tetravalent lipopeptides using c…

2011

Abstract The membrane-bound tumor-associated glycoprotein MUC1 is aberrantly glycosylated in cancer cells compared with normal cells, and is therefore considered an attractive target for cancer immunotherapy. However, tumor-associated glycopeptides from MUC1 do not elicit a sufficiently robust immune response. Therefore, antitumor vaccines were developed, which consist of MUC1 glycopeptides as the B epitopes and immune-stimulating toll-like receptor 2 (TLR 2) lipopeptide ligands. These fully synthetic vaccine candidates were prepared by solid-phase synthesis of the MUC1 glycopeptides. The Pam(3) Cys lipopeptide, also synthesized on solid-phase, was C-terminally coupled to oligovalent lysine…

Cyclotriveratrylene-Containing Porphyrins

2016

International audience; The C-3-symmetric cyclotriveratrylene (CTV) was covalently bonded via click chemistry to 1, 2, 3, and 6 zinc(II) porphyrin units to various host for C-60. The binding constants, Ka, were measured from the quenching of the porphyrin fluorescence by C-60. These constants vary between 400 and 4000 M-1 and are considered weak. Computer modeling demonstrated that the zinc(II) porphyrin units, [Zn], exhibit a strong tendency to occupy the CTV cavity, hence blocking the access for C-60 to land on this site. Instead, the pincer of the type [Zn]-[Zn] and in one case [Zn]-CTV, were found to be the most probable geometry to promote host-guest associations in these systems.

Synthesis of Globular Precursors

2015

o-Carborane (C2 B10 H12 ) was adapted to perform as the core of globular macromolecules, dendrons or dendrimers. To meet this objective, precisely defined substitution patterns of terminal olefin groups on the carborane framework were subjected to Heck cross-coupling reactions or hydroboration leading to hydroxyl terminated arms. These led to new terminal groups (chloro, bromo, and tosyl leaving groups, organic acid, and azide) that permitted ester production, click chemistry, and oxonium ring opening to be performed as examples of reactions that demonstrate the wide possibilities of the globular icosahedral carboranes to produce new dendritic or dendrimer-like structures. Polyanionic speci…

Synthesis of conformationally restricted 1,2,3-triazole-substituted ethyl β- and γ-aminocyclopentanecarboxylate stereoisomers. Multifunctionalized al…

2010

Abstract Stereoisomers of 1,2,3-triazole-functionalized, conformationally restricted β- or γ-amino esters with a cyclopentane skeleton were efficiently synthetized from the bicyclic β-lactam 6-azabicyclo[3.2.0]hept-3-en-7-one (1) and Vince γ-lactam (15) in five or six steps involving the azide–alkyne 1,3-dipolar cycloaddition of azido-substituted amino ester stereoisomers with nonsymmetric acetylenes. The azide–alkyne click reactions were investigated under thermal and Cu(I)-catalyzed conditions. Surprisingly, the thermally induced cycloaddition furnished the corresponding 1,4-triazoles regioselectively, which also took place selectively in response to Cu(I) catalysis.

Tetrazine Click Chemistry for the Modification of 1-Hydroxy-1,1-methylenebisphosphonic Acids: Towards Bio-orthogonal Functionalization of Gold Nanopa…

2016

Inverse electron demand Diels-Alder (iEDDA) was evaluated for the functionalization of gold nanoparticles. The reaction was first modelled with the free coating molecule 1-hydroxy-1,1-methylenebisphosphonate bearing an alkene functionality (HMBPene). A model tetrazine 3,6-dipyridin-2-yl-1,2,4,5-tetrazine (pyTz) was used, kinetic of the reaction was calculated and coupling products were analysed by NMR and HRMS. The reaction was then transposed at the nanoparticle surface. Gold nanoparticles bearing an alkene functionality were obtained using a one-pot methodology with HMBPene and the tetrazine click chemistry was evaluated at their surface using pyTz. The successful coupling was assessed by…

Clickable poly-L-lysine for the formation of biorecognition surfaces

2019

Biomolecules are immobilized onto surfaces employing the fast and stable adsorption of poly-l-lysine (PLL) polymers and the versatile copper-free click chemistry reactions. This method provides the combined advantages of versatile surface adsorption with density control using polyelectrolytes and of the covalent and orthogonal immobilization of biomolecules with higher reaction rates and improved yields of click chemistry. Using DNA attachment as a proof of concept, control over the DNA probe density and applicability in electrochemical detection are presented.

Chemical Strategies for the Synthesis of Protein–Polymer Conjugates

2012

Protein-polymer conjugates have achieved tremendous attention in the last few years. The synergistic combination of properties has led to certain advantages in bio-applications. Over the past few years, numerous chemical strategies have been developed to conjugate different synthetic polymers onto proteins, most of which can be summarized within the scope of click-chemistry. Here we highlight conjugation strategies based on available functional groups present on the synthetic polymer and existing groups of proteins from the natural pool. In particular, the chapter organizes the various possible reactions by classes of functional groups present on protein surfaces, deriving from selected ami…