Factors influencing the performance of organocatalysts immobilised on solid supports: A review

• Zsuzsanna Fehér,
• Dóra Richter,
• Gyula Dargó and
• József Kupai

Beilstein J. Org. Chem. 2024, 20, 2129–2142, doi:10.3762/bjoc.20.183

• influence of various linkers of cinchona squaramide organocatalysts immobilised on a poly(glycidyl methacrylate) (PGMA) solid support [127]. The support consisted of well-defined monodispersed PGMA microspheres, which were prepared through thorough parameter optimisation. Three amine-functionalised cinchona

Cage-like microstructures via sequential Ugi reactions in aqueous emulsions

• Rita S. Alqubelat,
• Yaroslava A. Menzorova and
• Maxim A. Mironov

Beilstein J. Org. Chem. 2024, 20, 2078–2083, doi:10.3762/bjoc.20.179

• removing the solvent, the resulting structure could be easily identified using optical microscopy. They were cage-like microspheres with an average diameter corresponding to the diameter of droplets in the Pickering emulsion (Figure 2). The surface of the droplets was covered with a network of individual

• a cage-like structure on the surface of emulsion droplets). Thus, when the amount of cross-linking agent at the second stage was halved to 5 mol % relative to chitosan, less durable microspheres were obtained. When the solvent was removed, they opened up, forming a cap-like structure (Figure 4A). An

• a narrow pH value range. This allowed to control the process of cage-like-structure formation. Changing the conditions of the Ugi reaction made it possible to obtain various structures, including cage- and cap-like structures, as well as hollow microspheres. Due to the developed surface, these

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• hydrophobic effect and to host–guest π–π interactions. Hydrophobic surface simulations showed that TBTQ-(OG)6 and C60 forms an amphiphilic supramolecular host–guest complex, which further assembles to microspheres with diameters of 0.3–3.5 μm, as determined by scanning electron microscopy. Keywords

• : fullerenes; host–guest systems; microspheres; supramolecular chemistry; tribenzotriquinacene; Introduction In the field of supramolecular chemistry, host–guest association through noncovalent interactions is an interesting and exciting topic, especially for the encapsulation of various fullerenes, such as

• of this host with C60 and C70-fullerene was investigated in co-organic solvents and in aqueous solution. The hydrophobic surface simulation of this host indicated the formation of a supra-amphiphilic system, which, as shown by scanning electron microscopy, further self-assembles into microspheres in

Palladium nanoparticles supported on chitin-based nanomaterials as heterogeneous catalysts for the Heck coupling reaction

• Tony Jin,
• Malickah Hicks,
• Davis Kurdyla,
• Sabahudin Hrapovic,
• Edmond Lam and
• Audrey Moores

Beilstein J. Org. Chem. 2020, 16, 2477–2483, doi:10.3762/bjoc.16.201

• , yet with either very high temperatures greater than 100 °C or using organic solvents such as toluene. The comparison with recent work in using chitin microspheres shows that chitin-based supports are potentially valuable support materials, with full product conversion in only 10 h, yet with mostly

Activated carbon as catalyst support: precursors, preparation, modification and characterization

• Melanie Iwanow,
• Tobias Gärtner,
• Volker Sieber and
• Burkhard König

Beilstein J. Org. Chem. 2020, 16, 1188–1202, doi:10.3762/bjoc.16.104

• either remain in the solvent or were removed by the gas stream resulting in the desired porous carbon spheres (Figure 1) [95]. Suslick and co-workers used the USP process for the preparation of well-dispersed iron impregnated porous carbon microspheres. An iron source (FeCl3 or Fe(NO3)3 is already added

Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril

• Mohammad A. Alnajjar,
• Jürgen Bartelmeß,
• Robert Hein,
• Pichandi Ashokkumar,
• Mohamed Nilam,
• Werner M. Nau,
• Knut Rurack and
• Andreas Hennig

Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171

• 77.9 µs, respectively. Fluorescence microscopy images of 1 mg/mL polymer microspheres a) with or b) without surface-bound CB7 after incubation with 10 nM 5 and 1 µM AMADA in 10 mM citrate, pH 3.3 (30% (v/v) ACN in water) and centrifugation to immobilize 5 through supramolecular host–guest binding

Fluorogenic PNA probes

• Tirayut Vilaivan

Beilstein J. Org. Chem. 2018, 14, 253–281, doi:10.3762/bjoc.14.17

• probe. One of the earliest examples makes use of PNA probes immobilized on fluorescence-polymer-coated polystyrene microspheres and a quenching DNA strand [106]. The fluorescence of the microsphere was restored upon displacement of the quencher DNA strand by the DNA target in a sequence-dependent manner

Regulation of integrin and growth factor signaling in biomaterials for osteodifferentiation

• Qiang Wei,
• Theresa L. M. Pohl,
• Anja Seckinger,
• Joachim P. Spatz and
• Elisabetta A. Cavalcanti-Adam

Beilstein J. Org. Chem. 2015, 11, 773–783, doi:10.3762/bjoc.11.87

• together for developing new biomaterials to enhance bone regeneration. For example, the microspheres with immobilized RGD peptide and adsorbed BMP-2 exhibits high potential for cell adhesion and differentiation of MSCs [86]. In another case, the pro-osteogenic α2β1 integrin-specific GFOGER peptide ligands

Glycodendrimers: tools to explore multivalent galectin-1 interactions

• Jonathan M. Cousin and
• Mary J. Cloninger

Beilstein J. Org. Chem. 2015, 11, 739–747, doi:10.3762/bjoc.11.84

• concentration of the dendrimer (220:1, 9:1, or 3:1 ratio of galectin-1 to dendrimer, respectively). Fluorescent microsphere standards (FluoSpheres Fluorescent Microspheres, Molecular Probes) and image analysis software (Pixcavator 6.0) were used for size quantifications. The results from the fluorescence

• microsphere standards (200 nm, 1000 nm, and 10000 nm reported diameter) (FluoSpheres Fluorescent Microspheres, Molecular Probes) and image analysis software (Pixcavator 6.0). At a constant concentration of galectin-1 (40 µM), aggregate size was measured at ratios of galectin-1 to glycodendrimer of 220:1, 9:1

Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

• Tor E. Kristensen

Beilstein J. Org. Chem. 2015, 11, 446–468, doi:10.3762/bjoc.11.51

• -load homopolymers by solution copolymerization [46][47], crosslinked polymer microspheres by dispersion copolymerization [47], crosslinked polymer beads by suspension copolymerization [47][48], catalytic core–shell micelles (nanoreactors) [68], hydrophobic nanogel particles by emulsion polymerization