Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• and heterogeneous Brønsted acid catalyst, which are both required for independent steps in the synthesis [132]. They suggested that the porphyrin was protonated by the amberlyst-15 sulphonate groups and immobilised to the solid surface by electrostatic forces, rationalising the observed change in

A heteroditopic macrocycle as organocatalytic nanoreactor for pyrroloacridinone synthesis in water

• Piyali Sarkar,
• Sayan Sarkar and
• Pradyut Ghosh

Beilstein J. Org. Chem. 2019, 15, 1505–1514, doi:10.3762/bjoc.15.152

• subjected to various studies like SEM, TEM and DLS experiments. The DLS data revealed that the dispersed particles size in the aqueous phase varied from ≈60 nm to ≈105 nm (Figure 2a). Interestingly, when the same dispersion was used for the analysis of the particle size distribution on a solid surface, i.e

Ni nanoparticles on RGO as reusable heterogeneous catalyst: effect of Ni particle size and intermediate composite structures in C–S cross-coupling reaction

• Debasish Sengupta,
• Koushik Bhowmik,
• Goutam De and
• Basudeb Basu

Beilstein J. Org. Chem. 2017, 13, 1796–1806, doi:10.3762/bjoc.13.174

• ]. However, only few graphene-based metal nanocomposites have been recognized for organic cross-coupling reactions [38][39][40][41][42]. In general, bare Ni NPs are very unstable and readily oxidized in air [43]. A few literature reports are available where Ni species immobilized on a solid surface have been

Optimized methods for preparation of 6^I-(ω-sulfanyl-alkylene-sulfanyl)-β-cyclodextrin derivatives

• Eva Bednářová,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2016, 12, 349–352, doi:10.3762/bjoc.12.38

• more hydrophilic and flexible oligoethylene glycol linker, which have been successfully applied in several studies to position the CD units at a sufficient distance from the solid surface. These linkers also have the advantage, compared to the aliphatic chain linkers, in a lower tendency to form an

Weakly nucleophilic potassium aryltrifluoroborates in palladium-catalyzed Suzuki–Miyaura reactions: relative reactivity of K[4-RC₆F₄BF₃] and the role of silver-assistance in acceleration of transmetallation

• Vadim V. Bardin,
• Anton Yu. Shabalin and
• Nicolay Yu. Adonin

Beilstein J. Org. Chem. 2015, 11, 608–616, doi:10.3762/bjoc.11.68

• -coupling product is no more than 5% in 8 h. 2. It is very likely that transmetallation of ArPdLnX with K[4-RC6F4BF3] proceeds on the surface of the silver(I) compounds (K[4-RC6F4BF3] and AgmY are insoluble in toluene). Neutral complex ArPdLnX is adsorbed on the acidic center (Ag+) of the solid surface to

Synthesis and surface grafting of a β-cyclodextrin dimer facilitating cooperative inclusion of 2,6-ANS

• Lars W. Städe,
• Thorbjørn T. Nielsen,
• Laurent Duroux,
• Reinhard Wimmer,
• Kyoko Shimizu and
• Kim L. Larsen

Beilstein J. Org. Chem. 2015, 11, 514–523, doi:10.3762/bjoc.11.58

• fluorescence spectroscopy that the inclusion of the fluorescent guest into both cavities of the β-CD dimer is maintained when grafted onto a solid surface. Keywords: 2,6-ANS; β-cyclodextrin dimer; silicon dioxide; surface grafting; total internal reflection fluorescence spectroscopy; Introduction Since the

• form 1:2 complexes with parent β-CD. Further, it is demonstrated that the β-CD dimer can be surface-grafted onto solid silicon dioxide surfaces, and by employing TIRF spectroscopy it was shown that the β-CD dimer maintains its inclusion complex properties when grafted onto a solid surface. Experimental

Properties of cationic monosubstituted tetraalkylammonium cyclodextrin derivatives – their stability, complexation ability in solution or when deposited on solid anionic surface

• Martin Popr,
• Sergey K. Filippov,
• Nikolai Matushkin,
• Juraj Dian and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2015, 11, 192–199, doi:10.3762/bjoc.11.20

• surface of polymeric Nafion® 117 membrane via electrostatic interactions. Deposition kinetics and coverage of the surface were determined by ELSD. Finally, the ability of the CD derivatives bound to the solid surface to encapsulate aromatic compounds from aqueous solution was measured by UV–vis

• spectroscopy. The obtained results are promising for future industrial applications of the monosubstituted β-CD derivatives, because the preparation of cationic CD derivatives is applicable in large scale, without the need of chromatographic purification. Their ionic deposition on a solid surface is simple

• , yet robust and a straightforward process as well. Keywords: cyclodextrins; inclusion properties; solid surface; tetraalkylammonium derivatives; thermal stability; Introduction Cyclodextrins (CDs) are a very interesting group of natural macrocyclic carbohydrates, which were first described by

Synthesis of a bifunctional cytidine derivative and its conjugation to RNA for in vitro selection of a cytidine deaminase ribozyme

• Nico Rublack and
• Sabine Müller

Beilstein J. Org. Chem. 2014, 10, 1906–1913, doi:10.3762/bjoc.10.198

• a biotin was introduced. Upon periodate oxidation of the 3'-cis diol of the RNA library molecules, the produced dialdehyde is thought to react with the primary amino group of the cytidine derivative allowing immobilization of the resulting modified RNAs onto a solid surface through biotin

Silica sulfuric acid: a reusable solid catalyst for one pot synthesis of densely substituted pyrrole-fused isocoumarins under solvent-free conditions

• Sudipta Pathak,
• Kamalesh Debnath and
• Animesh Pramanik

Beilstein J. Org. Chem. 2013, 9, 2344–2353, doi:10.3762/bjoc.9.269

• pyrrole-fused isocoumarins, which employs solid-supported silica sulfuric acid (SSA) as catalyst, has been developed. When the mixture of ninhydrin adducts of acetylacetone/ethyl acetoacetate and primary amines was heated on the solid surface of SSA under solvent-free conditions, the pyrrole-fused

• chemical processes. Hence, we have carried out the synthesis by dissolving the substrate 7 and aniline in a minimum volume of chloroform, soaked them on the solid surface of solid Brønsted acid catalysts, such as silica gel and melamine sulfonic acid (MSA), dried the mixture under vacuum, and heated the

• ]. Based on the results of Table 2 and the fact that SSA plays the role of transferring protons from its solid surface, a probable mechanism for the formation of isocoumarins 5 or 8 is explicated in Scheme 3. The protonation and activation of the hydroxy group of dihydroxy indenofuran (6 or 7) by the

Gallium-containing polymer brush film as efficient supported Lewis acid catalyst in a glass microreactor

• Rajesh Munirathinam,
• Roberto Ricciardi,
• Richard J. M. Egberink,
• Jurriaan Huskens,
• Michael Holtkamp,
• Herbert Wormeester,
• Uwe Karst and
• Willem Verboom

Beilstein J. Org. Chem. 2013, 9, 1698–1704, doi:10.3762/bjoc.9.194

• ]. However, only a limited number of papers are known dealing with heterogeneous Lewis acid catalysis, where a Lewis acid is tethered onto a solid surface like silica or gold [12][13]. Furthermore, to the best of our knowledge, there are no examples of the immobilization of a Lewis acid to a microreactor