On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

• Daniel Straub,
• Markus Gross,
• Mona E. Arnold,
• Julia Zolg and
• Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

• recognizing that the donor dendron is large and its inertia prevents fast conformational changes between the D0 and D1 states. This inertia is also reflected in the increasing fluorescence lifetimes, which increase from τ = 17.3 ns for G2TTM, to τ = 48.8 ns for T3TTM and τ = 120.0 ns for G4TTM. Moreover, the

• counterintuitive effect of an increasing D0 to D1 energy gap and ϕ with growing donor strength (from G2TTM to G4TTM) has been explained by a reduction of non-radiative relaxation processes, due to the decrease of the electron–electron repulsion in the occupied dendron orbitals. In a similar fashion, a simple

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

• acceptor to create a dendron-like structure. To overcome the high steric hindrance of both coupling partners, careful optimization of the LG and the reaction temperature was imperative [118][278][280][282]. A [31 + 30 + 30 + 30 + 30] fragment coupling allowed assembling a 151mer polymannoside 97, the

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

• trimesic acid scaffold by PyBOP coupling in DMF and NMM as weak base. After subsequent size exclusion chromatography, the ready to use azide-functional monomer 7 was isolated in high purity. The peptide amphiphile was finally conjugated to the propargylated sulfated [G2] oligoglycerol dendron 8 via a

• applications. However, depending on the nature of the functional groups, the influence on the self-assembly behavior may not be neglected. In the present work, the installation of a sulfated oligoglycerol dendron introduces eight anionic charges to the periphery of the peptide amphiphile II that possibly

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

• 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

• solid was dispersed in an aqueous solution of CuCl2⋅3H2O for 10 min. The copper species was reduced with an aqueous solution of NaBH4. The metal–dendron SBA-15 material was filtrated, washed with deionized water, and dried to produce x wt % CuYAu–Gx-AAA–SBA-15 (x wt % = weight percent loading of Cu, Y

• = Cu/Au molar ratio, Gx = dendrimer generation, and AAA = dendron type). After the preparation and characterization of the CuYAu–Gx-AAA–SBA-15 catalyst, the material was employed in a triazole synthesis, and it was established that the catalyst was efficient in the Sharpless–Meldal C–N bond formation

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

• disappointment, the attempted O,O’-bis-alkylation of 1 with 1-iodooctane (Williamson etherification, Table 1, entry 1), afforded a multicomponent reaction mixture (TLC monitoring, 100% conversion of 1), from which we succeeded in isolating only G-0 chloro-dendron 2a and the O,O’,N-tris-alkylated side product 2b

• cyanuric chloride with commercial 4-(n-octyloxy)aniline (Table 1, entry 2) gave the desired G-0 chloro-dendron 2a with excellent yield. We note the choice of several authors towards the synthesis of 4-(n-octyloxy)aniline by Williamson etherification of 4-nitrophenol or of N-acetyl-4-aminophenol

• )aniline preparation; we also took into account its convenient price. Using G-0 dendron 2a, we synthesised G-1 dendrons in two (→ D-Cl) or three (→ D-N

  NH) orthogonal transformations, with excellent overall yields (90% and 84% from 2a, respectively). The complete chemoselectivity observed during the

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

• Cristina Cebrián and
• Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124

• )-9,9′-spirobifluorene. For all devices, emission similar to those recorded in solution was obtained independently of the doping concentration. Moreover, the decreasing driving voltages measured were ascribed to better charge transport properties in the emissive layer upon increasing the dendron

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• other personal care products [164]. The highest selectivity so far reported in batch conditions was observed using dendron-stabilized PdNP catalysts with quinoline additives (97% ene, 98% Z) [165]. The only example described under continuous flow used the Pd@monobor catalysts to achieve a 96% conversion

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

• and a high electrochemical response [74]. CuAAC has been successfully used to immobilize molecules on polymers and biopolymers as well as to join sugars to peptides and proteins. CD-polyglycerol dendron amphiphiles (CD-PG) have also been obtained. This derivative showed high encapsulation efficiency

Multivalent polyglycerol supported imidazolidin-4-one organocatalysts for enantioselective Friedel–Crafts alkylations

• Tommaso Pecchioli,
• Manoj Kumar Muthyala,
• Rainer Haag and
• Mathias Christmann

Beilstein J. Org. Chem. 2015, 11, 730–738, doi:10.3762/bjoc.11.83

• tedious and multistep syntheses using either divergent or convergent approaches are arguably the reason for their limited use as support in organic synthesis [18]. To overcome these obstacles, a hybrid dendron-polymer might constitute a valuable alternative for high-loading platforms [19], despite the use

• of solid support such as polystyrene may lead to the disadvantage of operating in heterogeneous media. In contrast to the stepwise syntheses of dendrimers and dendron hybrids, the hyperbranched polymers can be easily obtained in kilogram scale through one-pot reactions [10], maintaining properties

• decorated dendron-hybrids [47], the presence of water was crucial for aldol and Baylis–Hillman reactions, as recently reported by Miller and Portnoy [48]. To the best of our knowledge, the immobilization of chiral organocatalysts on hyperbranched polymeric support has remained unexplored. Therefore, we

Redox active dendronized polystyrenes equipped with peripheral triarylamines

• Toshiki Nokami,
• Naoki Musya,
• Tatsuya Morofuji,
• Keiji Takeda,
• Masahiro Takumi,
• Akihiro Shimizu and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2014, 10, 3097–3103, doi:10.3762/bjoc.10.326

• scan rate was 100 mV/s. Two synthetic approaches toward the peripherally functionalized dendronized polystyrenes (blue dotted line = polystyrene, orange sector = dendron of the 1st generation, dark orange sector = dendron of the 2nd generation). (a) Peripheral functionalization of the dendronized

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

• 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

• -fucopyranosyloxyamine [18] were used as sample monosaccharides for the conjugation of the dendron (Scheme 1). Synthesis of dendrons Zero, first and second generation heterobifunctional dendrons 1–3 were synthesized starting from 9-decen-1-ol (12) or selected building blocks 13 and 14 (Scheme 2) [11] by esterification

• synthesized from commercial L-fucopyranose in 4 and 5 steps, respectively, as already reported by Flitsch and co-workers [17] and Dumy and co-workers [18]. Dendron conjugation to L-fucose by reductive amination α-L-(2-Aminoethyl) fucopyranoside (4) was conjugated first to G0 dendron 1 by reductive amination

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

• -products together with a better assessment of complete surface group modifications. Hence, known 14 [36] was first cycloadded to mannosylazide 3 under the above CuAAc conditions. The “click reaction” proceeded exceptionally efficiently and provided bromoacylated dendron precursor 18 in 94% yield

• ≡CH); HRMS (+TOF-HRMS, m/z): [M + H]+ calculated for C51H57N3O15, 952.3862; found, 952.3843 (Δ = −2.10 ppm); [M + Na]+: calculated for 974.3682; found, 974.3662 (Δ = −2.05 ppm). Synthesis of bromoacylated dendron 18: To a solution of tripropargylated synthon 14 (140.0 mg, 393.0 μmol, 1.00 equiv) and

• ). Synthesis of azidoacylated dendron 19: To a stirring solution of brominated trivalent dendron 18 (121.0 mg, 75.2 μmol, 1.00 equiv) in dry DMF (1.5 mL) was added under a nitrogen atmosphere sodium azide (7.3 mg, 112 μmol, 1.50 equiv). After stirring overnight at room temperature, the solvent was removed

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

• 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

• etherification reaction with MDC to deliver glycodendron 7 of the next dendron generation. This in turn, can be further elaborated to give the alcohol 8 and the formerly unknown glycodendron alkene 9. Initially, postsynthetic focal point modification of glycodendrons was attempted by direct etherification

Human dendritic cell activation induced by a permannosylated dendron containing an antigenic GM₃-lactone mimetic

• Renato Ribeiro-Viana,
• Elena Bonechi,
• Javier Rojo,
• Clara Ballerini,
• Giuseppina Comito,
• Barbara Richichi and
• Cristina Nativi

Beilstein J. Org. Chem. 2014, 10, 1317–1324, doi:10.3762/bjoc.10.133

• dendron has the adequate size and valency to efficiently interact with this receptor. Dendron 7 (Scheme 1), presenting an azido group at the focal position, was synthesized as previously described [35]. This functionalization permits, in a further step, the conjugation of any molecule conveniently

• second strategy requires a system which should be able to selectively target DCs in vivo. In this work, we have shown how to combine in a single entity a mannosylated dendron able to selectively interact with DCs through DC-SIGN armed with a synthetic antigen. This ditopic glycodendron 5 demonstrated to

• dendron interacting with the surface receptor DC-SIGN. These promising and preliminary biological results pave the way to the design of glycodendritic structures bearing antigen cargos as a selective vector to target APCs for stimulating immune responses. Further experiments must be performed to verify

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

• bisamine functionalities and result in increased compound stability. Structure 7 was successfully prepared through a multi-step synthetic scheme [21]. Condensation of 1 with 2.1 equivalents of benzaldehyde 7 followed by in situ reduction with NaBH4 and acidification with 2 N HCl provided dendron 8 (Scheme

•  2). Compound 8, itself an AB2 monomer similar to compounds 4a–4g, was stable in CDCl3 as visualized by 1H NMR spectroscopy. Due to the improved stability of 8 in organic solvents, second-generation dendrimers containing the dendron and triphenol cores 5, 9, and 10 (Schemes 1 and 3) were designed

• to play an important role. Current efforts are focused on incorporating the bisamine dendron motif into additional supramolecular structures such as star polymers and hyperbranched systems and examining how fine-tuning the steric and electronic nature of the bisamine AB2 monomers influences the

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

• ':6',2''-terpyridine (4) [47], which was readily deprotected by CsF in methanol to give the targeted 4'-ethynyl-2,2':6',2''-terpyridine (5) (Scheme 1). Cross-coupling of ethynylated tpy building block 5 with iodinated G1-dendron 6 and G2-dendron 7 [42] under standard Sonogashira-type coupling

• , MALDI–TOF-mass spectrometry and elemental analysis as well as by cyclic voltammetry and UV–vis spectroscopy. Electronic absorption and emission properties. One of our goals was to study electronic communication between the core metal complex and the attached oligothiophene dendron as a function of

• further supported by theoretical calculations (see below). For ligands 8 and 9, with increasing generation of the dendron from G1 and G2, a slight red-shift in the lowest energy absorption maximum and a significant enhancement in the molar absorption coefficient were observed. Furthermore, the absorption

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

• strategy. A convergent synthetic approach was chosen for the conjugation of pyrrolidine 4 and pyrrolidine-based dendron 5 (see Scheme 1) to the calix[4]arene core, via intermediate 11, in order to obtain iminosugar-based calixarene-dendrimers 2 and 3 (see Scheme 2). The starting calixarene used in this

• the coupling with pyrrolidine 4 in order to obtain the pyrrolidine-based dendron 5 to be used in assembling the second-generation calixarene-dendrimer 3. In particular, succinimidyl-activated pyrrolidine 9 was obtained by hydrolysis of ester groups in 8 followed by treatment with DCC/NHS (two steps

• of TFA to obtain the pyrrolidine-based dendron 5 (Scheme 1), which was used in the next step without further purification. Using the SuO-activated calix[4]arene 11 as the scaffold, the planned convergent synthetic approach was completed to afford the first (2) and second (3) generation iminosugar

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

• 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

• method produced very small Au NPs of diameter 1.2 ± 0.4 nm coated exclusively with dendron 16. Using the two-step method, hybrid Au NPs with diameters of 1.7 ± 0.4 nm were prepared, with a surface concentration of approximately 40% of the mesogenic dendron on the surface, as determined by 1H NMR

• were partially coated with dendron 19 (Figure 21) by solvent-mediated ligand exchange to give a final surface coverage of ~4:5 dendron to dodecanethiol. This represents a rather dense surface coverage, corresponding to an average chain cross-sectional area of AChain = 18.1 ± 0.5 Å2, which is below the

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

• 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

• systems); this can be attained if the core of the dendron possesses several functions. We report here the use of hexachlorocyclotriphosphazene (N3P3Cl6) for such a purpose, which allows the gathering of five fluorescent dansyl groups in a small dendron, thanks to the specific functionalization of N3P3Cl6

• [15]. The method elaborated is also useful for the grafting of dyes, as will be illustrated with the dabsyl dye. We also paid particular attention to the nature of the remaining function (usable for the grafting of the dendron). We choose an aldehyde and a primary amine, both being well-known for

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

• aspartic acid with 1-dodecanol). The second (G2) and third generations (G3) were synthesized convergently in 75 and 60% yields, respectively, by repeating a two-reaction cycle, i.e., by removal of the carbobenzyloxy group of the lower-generation dendron by hydrogenation, and then coupling the resulting N

Olefin metathesis in nano-sized systems

• Didier Astruc,
• Abdou K. Diallo,
• Sylvain Gatard,
• Liyuan Liang,
• Cátia Ornelas,
• Victor Martinez,
• Denise Méry and
• Jaime Ruiz

Beilstein J. Org. Chem. 2011, 7, 94–103, doi:10.3762/bjoc.7.13

• the phenol triallyl dendron p-HOC6H4C(CH2CH=CH2)3 and iterations [42][52][53]. This allowed the building of large dendrimers and the extension of their tethers with alkenyl termini. CM of these large olefin-terminated dendrimers with acrylic acid was carried out in order to synthesize dendrimers

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

• structure for a diverse range of applications [1][2]. Indeed, these highly branched macromolecules possess precise constitutions and a large number of functional groups which confer upon them unique properties [3]. The word was coined from a combination of dendron (Greek = tree) and polymer. Generally, a

• 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

• before to yield G4. G4 was then treated with 3-hydroxybenzaldehyde in dry THF at 30 °C to give G5. Finally, G5 was reacted with 4-aminophenol in dry EtOH at reflux temperature to afford the dendrimer G6. As the size of the dendron increases the reaction is less effective and the yields are reduced. To