Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

Supramolecular polymerization of sulfated dendritic peptide amphiphiles into multivalent L-selectin binders

• David Straßburger,
• Svenja Herziger,
• Katharina Huth,
• Moritz Urschbach,
• Rainer Haag and
• Pol Besenius

Beilstein J. Org. Chem. 2021, 17, 97–104, doi:10.3762/bjoc.17.10

• could be observed, thus corroborating the interpretations from dry TEM experiments. Attaching functional groups to the dendritic peptide amphiphiles – and thus the supramolecular polymers – by exchanging one of the shielding dendritic tetra(ethylene glycol) dendrons is important with regard to potential

• sulfated dendrons and supports the application of the supramolecular polymers in biological applications. In order to compare the morphology of the self-assembled sulfated compound II with the TEG-decorated compound I, TEM and cryo-TEM experiments were performed (Figure 2B and 2C). Based on the outcome

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

• loss of catalytic activity. Using a multistep solid-phase procedure, Shantz et al. reported on SBA-15 functionalized with melamine-based dendrons (Scheme 3) [27]. The Cu and Cu/Au nanoparticles were then supported on this new composite to generate a nanocatalyst. The catalytic application of this

• was grown one or two times by repeating the above-mentioned process to generate G2-AAA–SBA-15 and G3-AAA–SBA-15 composites, respectively. Generally, x and AAA in Gx-AAA–SBA-15 refer to the dendron generation and diamine (AMP for dendrons containing 4-aminomethylpiperidine and PIP for dendrons

Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

• Cristina Morar,
• Pedro Lameiras,
• Attila Bende,
• Gabriel Katona,
• Emese Gál and
• Mircea Darabantu

Beilstein J. Org. Chem. 2018, 14, 1704–1722, doi:10.3762/bjoc.14.145

• stoichiometric carboxyl/amino 1:3 neutralisations (→ G-2 ionic trimers). These transformations connected G-1 chloro- and amino-termini dendrons to m-trivalent cores (triazin-2,4,6-triyl and benzene-1,3,5-triyl units) or tripodands (central building blocks), such as N-substituted melamines with 4-hydroxyphenyl or

• (bromomethyl)benzene [37] and trimesic acid trichloride [38] are commercial chemicals, classically known as reactive m-trivalent (hetero)aryl halo compounds, that are easily convertible into dendritic cores in reactions with various dendrons as N- and O-nucleophiles. The preparation of the central building

• (in B) and rigid 1,4-phenylene with adjustable alkoxy-spacers (n = 1, 3, in C1 and C3, respectively). G-1 chloro- and piperazine-dendrons, D-Cl and D-N

  NH, as well as central building blocks B, C1 and C3, had s-triazine rings linked by C(s-triazine)–N(exocyclic) partial double bonds, which exist due

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• , while nanostructure size and shape were regulated according to the structure of the CD-PG dendrons [75]. CD-based polymers can be easily prepared under MW. Biswas et al. have prepared a number of macromolecular structures from α-, β-, γ-CDs by crosslinking reactions with toluene diisocyanate and

Bifunctional dendrons for multiple carbohydrate presentation via carbonyl chemistry

• Davide Bini,
• Francesco Nicotra and
• Laura Cipolla

Beilstein J. Org. Chem. 2014, 10, 1686–1691, doi:10.3762/bjoc.10.177

• Davide Bini Francesco Nicotra Laura Cipolla Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milano, Italy 10.3762/bjoc.10.177 Abstract The synthesis of new dendrons of the generations 0, 1 and 2 with a double bond at the focal point and a

• carbonyl group at the termini has been carried out. The carbonyl group has been exploited for the multivalent conjugation to a sample saccharide by reductive amination and alkoxyamine conjugation. Keywords: bis-MPA; carbohydrates; dendrons; levulinic acid; multivalency; multivalent glycosystems

• understand these phenomena, dendrimers and dendrons have been developed to provide multivalent glycoconjugates [13][14]. Here, we propose the synthesis of novel dendron structures which allow for the multivalent conjugation of carbohydrates via carbonyl chemistry. Results and Discussion The

Synthesis and solvodynamic diameter measurements of closely related mannodendrimers for the study of multivalent carbohydrate–protein interactions

• Yoann M. Chabre,
• Alex Papadopoulos,
• Alexandre A. Arnold and
• René Roy

Beilstein J. Org. Chem. 2014, 10, 1524–1535, doi:10.3762/bjoc.10.157

• expected. On the other hand, rather counter-intuitive tendencies were observed since the apparently slightly extended structure 17 was measured as the smallest molecule of the family in water. A specific spatial arrangement of the dendrons that emanate from 1,3,5-O-alkylations on the aromatic core in 17

Postsynthetic functionalization of glycodendrons at the focal point

• Thisbe K. Lindhorst and
• Katharina Elsner

Beilstein J. Org. Chem. 2014, 10, 1482–1487, doi:10.3762/bjoc.10.152

• example the glycodendrimers, have become valuable tools during the last two decades [2]. Typical glycodendrimers consist of (hyper)branched dendritic core molecules which are decorated with specific sugars in their periphery [3][4][5]. In addition to dendrimers, also so-called dendrons have been

• frequently applied for the synthesis of multivalent glycoconjugates [6]. Dendrons resemble a branched fragment of a whole dendrimer with an orthogonal functional group (FG) at the focal point of the molecular fragment (Figure 1a). This molecular architecture comprises the possibility to anchor a multivalent

• films, liposomes, or membranes. Focal functionalization of dendrons can be performed prior to modification of the multivalent dendron periphery, or as postsynthetic modification. However, postsynthetic functionalization of the focal point of a rather bulky molecule is not necessarily facile owing to

Bis(benzylamine) monomers: One-pot preparation and application in dendrimer scaffolds for removing pyrene from aqueous environments

• Olivia N. Monaco,
• Sarah C. Tomas,
• Meghan K. Kirrane and
• Amy M. Balija

Beilstein J. Org. Chem. 2013, 9, 2320–2327, doi:10.3762/bjoc.9.266

• benzaldehydes that resulted in unstable imines. An unprecedented first-generation bisamine-based dendrimer 6 was prepared but was found to degrade readily in organic solvents. More stable second-generation dendrimers composed of hybrid dendrons 8 and one of the three tri-phenol cores 5, 9, and 10 were

Synthesis, photophysical and electrochemical characterization of terpyridine-functionalized dendritic oligothiophenes and their Ru(II) complexes

• Amaresh Mishra,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2013, 9, 866–876, doi:10.3762/bjoc.9.100

• oligothienylene-ethynylene dendrons and their corresponding terpyridine-based ligands. Their complexation with Ru(II) led to interesting novel metallodendrimers with rich spectroscopic properties. All new compounds were fully characterized by 1H and 13C NMR, as well as MALDI–TOF mass spectra. Density functional

• . Photophysical studies of the complexes revealed broad absorption spectra covering from 250 to 600 nm and high molar extinction coefficients. The MLCT emission of these complexes were significantly red-shifted (up to 115 nm) compared to the parent [Ru(tpy)2]2+ complex. Keywords: dendrons; electrochemistry

• photophysical properties studied [33][34][35][36][37][38]. However, to our knowledge, tpy-functionalized dendritic oligothiophenes have not been synthesized so far. The complexation of these dendrons could lead to interesting nanosized materials containing different chromophores to study electronic energy

Flow photochemistry: Old light through new windows

• Jonathan P. Knowles,
• Luke D. Elliott and
• Kevin I. Booker-Milburn

Beilstein J. Org. Chem. 2012, 8, 2025–2052, doi:10.3762/bjoc.8.229

• -functionalised poly-L-lysine with alkyne tethered glycol-dendrons to form cyclobutenes [84]. The reactions were performed on a sub-millimolar scale, but the precise control over reaction conditions with the flow apparatus allowed for high yields of the complex dendronic products. Nettekoven et al. [85] trialled

Low-generation dendrimers with a calixarene core and based on a chiral C₂-symmetric pyrrolidine as iminosugar mimics

• Marco Marradi,
• Stefano Cicchi,
• Francesco Sansone,
• Alessandro Casnati and
• Andrea Goti

Beilstein J. Org. Chem. 2012, 8, 951–957, doi:10.3762/bjoc.8.107

• [38][39], which are objects of current investigations. Conclusion The coupling of low-generation dendrons, based on the chiral C2-symmetric dihydroxypyrrolidine 1, with a calix[4]arene scaffold allowed the construction of novel supramolecular architectures, i.e., iminosugar-analogue-based calixarene

Liquid-crystalline nanoparticles: Hybrid design and mesophase structures

• Gareth L. Nealon,
• Romain Greget,
• Cristina Dominguez,
• Zsuzsanna T. Nagy,
• Daniel Guillon,
• Jean-Louis Gallani and
• Bertrand Donnio

Beilstein J. Org. Chem. 2012, 8, 349–370, doi:10.3762/bjoc.8.39

• finding success for example in the case of polymer-coated NP hybrids [38][39][40][41]. Dendrimers and dendrons offer some advantages in this context, due to the ability to exert a high degree of control over their structure and composition, with their size readily increased through additional generational

• of liquid-crystalline and non-liquid-crystalline dendrons were prepared containing thiol or disulfide groups within their structures. Hybrid Au NP materials were prepared with cyanobiphenyl terminated dendron 16 (Figure 19) by using both direct and solvent-mediated ligand exchange methods. The direct

• the grafting of dendrons 221–3 (Figure 24) to carboxylic acid functionalised Au NPs of diameters 5.9 ± 0.6, 6.8 ± 0.7 and 6.8 ± 0.8 nm through a surface amidation reaction. Interestingly, the hybrids only displayed 2-D hexagonal organisation (TEM) when coated with the second generation dendron 222

Synthesis of dye/fluorescent functionalized dendrons based on cyclotriphosphazene

• Aurélien Hameau,
• Sabine Fuchs,
• Régis Laurent,
• Jean-Pierre Majoral and
• Anne-Marie Caminade

Beilstein J. Org. Chem. 2011, 7, 1577–1583, doi:10.3762/bjoc.7.186

• Functionalized phenols based on tyramine were synthesized in order to be selectively grafted on to hexachlorocyclotriphosphazene, affording a variety of functionalized dendrons of type AB5. The B functions comprised fluorescent groups (dansyl) or dyes (dabsyl), whereas the A function was provided by either an

• aldehyde or an amine. The characterization of these dendrons is reported. An unexpected behaviour of a fluorescent and water-soluble dendron based on dansyl groups in mixtures of dioxane/water was observed. Keywords: dabsyl; dansyl; dendrimer; dendron; fluorescence; Introduction Dendrimers constitute an

• most of their properties for instance in catalysis, for the elaboration of materials, or in biology [1][2]. Dendrons are also branched macromolecules, reminiscent of dendrimers, but which possess one functional group at the level of the core, in addition to the terminal groups [3]. Several hundreds of

Amphiphilic dendritic peptides: Synthesis and behavior as an organogelator and liquid crystal

• Baoxiang Gao,
• Hongxia Li,
• Defang Xia,
• Sufang Sun and
• Xinwu Ba

Beilstein J. Org. Chem. 2011, 7, 198–203, doi:10.3762/bjoc.7.26

• dendrons or dendrimers are of great significance because of their similarity to proteins in composition and topology [9][10][11], as well as their architectural difference from currently prevalent linear model peptides. However, little attention has been paid to the self-assembly of natural amino acid

Synthesis, spectral characterization, electron microscopic study and thermogravimetric analysis of a phosphorus containing dendrimer with diphenylsilanediol as core unit

• E. Dadapeer,
• B. Hari Babu,
• C. Suresh Reddy and
• Naga Raju Charmarthi

Beilstein J. Org. Chem. 2010, 6, 726–731, doi:10.3762/bjoc.6.85

• with a diphenylsilanediol core was synthesized using a divergent method. Several types of reactions were performed on dendrons of several sizes, either at the level of the core or the surface. The giant Schiff’s base macro molecule possesses 12 imine bonds and 8 hydroxy groups on the terminal phenyl

• molecule resembling a tree. Recently, dendrimers and dendrons have been defined in general terms for a class of hyper branched and poly functional macromolecules [4]. They are also called “cascade-type molecules”. Under ideal conditions, the molecular architecture is very uniform. A dendron is one of the

• been investigated [11] by several strategies of functionalization of the surface [12] or the branches [13] of dendritic compounds. Similarly, phosphorus-containing dendrons [14] are also becoming of interest. Considerable effort has been devoted to the functionalization of the periphery of dendrimers