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

• between 0.7 nm and 2 nm and thus, determination of specific surface areas is possible. In addition, phenol is the primarily used liquid-phase reference for adsorption studies. The adsorption capacity of phenol is influenced by oxygen-containing functional groups: basic properties promote the adsorption of

• -containing surface groups on the activated carbon materials. They could observe that gas phase oxidation led to a higher amount of mainly hydroxy and carbonyl groups, whereas liquid phase treatment with nitric acid results in an increase of carboxylic acid groups [110]. Lillo-Ródenas et al. used TPD for the

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• species 1O2(1Δg) has both electrons paired in a single orbital, while the electrons of the species 1O2(1Σg+) are paired in different orbitals. Both singlet states can be formed competitively, however, the conversion from 1O2(1Σg+) to 1O2(1Δg) is extremely fast in liquid-phase (k = 10−11 s), making the 1O2

Palladium-catalyzed Sonogashira coupling reactions in γ-valerolactone-based ionic liquids

• László Orha,
• József M. Tukacs,
• László Kollár and
• László T. Mika

Beilstein J. Org. Chem. 2019, 15, 2907–2913, doi:10.3762/bjoc.15.284

• yield of 88%. It should be noted that this reaction verified the reproducibility of the experiments (cf. Table 3, entry 1). Same amounts of substrates were added to the Pd catalyst contained in the ionic liquid phase followed by heating to 55 °C. In the second run 12% of decrease in the isolated yield

Nanopatterns of arylene–alkynylene squares on graphite: self-sorting and intercalation

• Tristan J. Keller,
• Joshua Bahr,
• Kristin Gratzfeld,
• Nina Schönfelder,
• Marcin A. Majewski,
• Marcin Stępień,
• Sigurd Höger and
• Stefan-S. Jester

Beilstein J. Org. Chem. 2019, 15, 1848–1855, doi:10.3762/bjoc.15.180

• higher concentration of 1b (of 1 × 10−6 M) in the supernatant liquid phase, polymorph B is observed, which was indexed with a unit cell of a = (5.6 ± 0.2) nm, b = (4.0 ± 0.2) nm, γ(a,b) = (74 ± 2)°. The (long) hexadecyloxy (OC16H33) side chains are (like in polymorph A) adsorbed along an HOPG main axis

Mechanochemical synthesis of hyper-crosslinked polymers: influences on their pore structure and adsorption behaviour for organic vapors

• Sven Grätz,
• Sebastian Zink,
• Hanna Kraffczyk,
• Marcus Rose and
• Lars Borchardt

Beilstein J. Org. Chem. 2019, 15, 1154–1161, doi:10.3762/bjoc.15.112

• obtained for diethyl ether (Table 1, entry 7) this sample has been denoted LAG-HCP and was investigated further. Vapor physisorption Since HCP is highly hydrophobic (proven before by water vapor physisorption [11]), the adsorption of non-polar adsorptives in the gas and liquid phase is strongly favored

• . Recently, the advantage of HCP over various commonly available adsorbents in the selective liquid phase adsorption of least polar component in aqueous solution has been demonstrated [46][47]. Herein, the adsorption properties for the organic vapors benzene and cyclohexane are reported and the differences

Unexpected polymorphism during a catalyzed mechanochemical Knoevenagel condensation

• Sebastian Haferkamp,
• Andrea Paul,
• Adam A. L. Michalchuk and
• Franziska Emmerling

Beilstein J. Org. Chem. 2019, 15, 1141–1148, doi:10.3762/bjoc.15.110

• effects. First, the lifetime of the initial molten/liquid phase was nearly doubled, suggesting that mechanical treatment has an important effect on this largely solution-phase reaction. This may be a result of heating, mechanical activation of the fluid-phase molecules or differences in energy for

Efficient synthesis of 4-substituted-ortho-phthalaldehyde analogues: toward the emergence of new building blocks

• Clémence Moitessier,
• Ahmad Rifai,
• Pierre-Edouard Danjou,
• Isabelle Mallard and
• Francine Cazier-Dennin

Beilstein J. Org. Chem. 2019, 15, 721–726, doi:10.3762/bjoc.15.67

• . The liquid phase was dried over MgSO4 and concentrated under reduced pressure to obtain a residue which was purified by two successive flash chromatography runs. The first one was run on 100% DCM mobile phase in order to eliminate DDQ residue (Rf = 0.9) and the second with ethyl acetate/hexane (3:1

Adhesion, forces and the stability of interfaces

• Robin Guttmann,
• Johannes Hoja,
• Christoph Lechner,
• Reinhard J. Maurer and
• Alexander F. Sax

Beilstein J. Org. Chem. 2019, 15, 106–129, doi:10.3762/bjoc.15.12

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• sulfonated polymer-carbon nanotubes composites (CNT-P-SO3H) 100–102 were described as outstanding catalysts for liquid phase transesterification of triglycerides 103 with methanol. The catalysts were also used for the esterification of oleic acid (106) with methanol. The important feature of this study is

Artificial bioconjugates with naturally occurring linkages: the use of phosphodiester

• Takao Shoji,
• Hiroki Fukutomi,
• Yohei Okada and
• Kazuhiro Chiba

Beilstein J. Org. Chem. 2018, 14, 1946–1955, doi:10.3762/bjoc.14.169

• linkages that can be formed between native functional groups would be safe alternatives, and are known as natural conjugates such as nucleopeptides and nucleolipids [49]. We have been developing alkyl chain soluble support (ACSS)-assisted liquid-phase methods, specifically for peptide and oligonucleotide

• of the starting material (Table 1, entries 1–3). The best result was obtained at 25 mM concentration in dichloromethane (CH2Cl2). Although tetrahydrofuran (THF) is one of the typical reaction solvents for ACSS-assisted liquid-phase synthesis, this was not the case for the 5’-phosphitylation (Table 1

• the work-up procedure routinely used for the ACSS-assisted liquid-phase method. Namely, the 5’-activated supported trinucleotide 2 was readily separated as a precipitate by the addition of acetonitrile, and washing the precipitate with acetonitrile simultaneously rinses away excess reagents to afford

Graphitic carbon nitride prepared from urea as a photocatalyst for visible-light carbon dioxide reduction with the aid of a mononuclear ruthenium(II) complex

• Kazuhiko Maeda,
• Daehyeon An,
• Ryo Kuriki,
• Daling Lu and
• Osamu Ishitani

Beilstein J. Org. Chem. 2018, 14, 1806–1812, doi:10.3762/bjoc.14.153

• formate generated in the liquid phase was analyzed via a capillary electrophoresis system (Otsuka Electronics Co., Model CAPI-3300). XRD patterns of g-C3N4 synthesized at different temperatures. A broad peak at around 22 degree, indicated by #, in XRD patterns originated from a glass folder for the

Spectroelectrochemical studies on the effect of cations in the alkaline glycerol oxidation reaction over carbon nanotube-supported Pd nanoparticles

• Dennis Hiltrop,
• Steffen Cychy,
• Karina Elumeeva,
• Wolfgang Schuhmann and
• Martin Muhler

Beilstein J. Org. Chem. 2018, 14, 1428–1435, doi:10.3762/bjoc.14.120

• control of selectivity. Moreover, additional parameters such as pH value, the nature of the ions and the concentration of glycerol in the liquid phase can be tuned in liquid-phase processes [4]. Monitoring of electrocatalytic reactions is challenging as all products are dissolved in the electrolyte. High

Correlation effects and many-body interactions in water clusters

• Andreas Heßelmann

Beilstein J. Org. Chem. 2018, 14, 979–991, doi:10.3762/bjoc.14.83

• ; Introduction The description of the intermolecular interactions between water molecules is essential for an understanding of the structures and properties of water through the different stages of assemblies, from the dimer over the liquid phase to the bulk phase. Moreover, many chemical processes are

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• heterogeneous catalysis Catalysis, in general, is divided into two major types, homogenous and heterogeneous. In homogeneous catalysis catalyst and substrates are both present and molecularly dissolved in the same phase (typically a liquid phase) [46]. Homogeneous catalysis involves the use of biocatalysts

A novel synthetic approach to hydroimidazo[1,5-b]pyridazines by the recyclization of itaconimides and HPLC–HRMS monitoring of the reaction pathway

• Dmitry Yu. Vandyshev,
• Khidmet S. Shikhaliev,
• Andrey Yu. Potapov,
• Michael Yu. Krysin,
• Fedor I. Zubkov and
• Lyudmila V. Sapronova

Beilstein J. Org. Chem. 2017, 13, 2561–2568, doi:10.3762/bjoc.13.252

• diaminoimidazole as a 1,3-C,N-dinucleophile to the activated C=C double bond to form intermediate 5 followed by recyclization involving the N1-amino group which leads to the formation of imidazo[1,5-b]pyridazines 9. Monitoring of the liquid phase composition of the reaction mixture by HPLC–HRMS showed that during

• probable routes of the cascade recyclization process, because ions of the protonable substances are only fixed in the given ESI–MS conditions, and precipitation of the product is observed as the reaction proceeds. The latter causes a decreased content of the imidazopyridazine 9d in the liquid phase is

Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity

• Tathagata Mukherjee,
• Soumik Biswas,
• Andreas Ehnbom,
• Subrata K. Ghosh,
• Ibrahim El-Zoghbi,
• Nattamai Bhuvanesh,
• Hassan S. Bazzi and
• John A. Gladysz

Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246

• consequence as one approaches the macromolecular limit of polytetrafluoroethylene. Fluorophilicities are typically quantified by fluorous/organic liquid/liquid phase partition coefficients [1][2][3]. The most common solvent combination is perfluoro(methylcyclohexane) (CF3C6F11) and toluene. The objective of

Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules

• Jan Podlesný,
• Lenka Dokládalová,
• Oldřich Pytela,
• Adam Urbanec,
• Milan Klikar,
• Numan Almonasy,
• Tomáš Mikysek,
• Jaroslav Jedryka,
• Iwan V. Kityk and
• Filip Bureš

Beilstein J. Org. Chem. 2017, 13, 2374–2384, doi:10.3762/bjoc.13.235

• to 215 °C, respectively. All compounds provided a very sharp peak of melting while the peaks of the decomposition were mostly broad (50–80 °C). The following thermal structure–property relationships can be concluded from the measured data: Compounds in series a are stable even in the liquid phase and

• approximately 50 °C higher melting point (e.g., 1a/1b with Tm = 261/215 °C). Thus, the insertion of an acetylene linker decreases the melting point and causes thermal instability in the liquid phase. Derivatives 1a/2a containing a 1,4-phenylene linker showed the highest Tm and Td values of 261/244 and 330/345

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178

• reactions in an environmentally-friendly fashion [17][18]. In this respect, there have been several turning points in the development of solid-state mechanochemistry. The first key discovery was made by Jones et al. who discovered the rate-accelerating effect of adding small catalytic quantities of a liquid

• phase to a mixture treated by manual grinding or ball milling [19]. What was in the beginning termed as "solvent-drop grinding" (SDG) eventually became "liquid-assisted grinding" or LAG, now a well-established method for improving the outcome of mechanochemical reactions [20]. In continuation of this

Correlation of surface pressure and hue of planarizable push–pull chromophores at the air/water interface

• Frederik Neuhaus,
• Fabio Zobi,
• Gerald Brezesinski,
• Marta Dal Molin,
• Stefan Matile and
• Andreas Zumbuehl

Beilstein J. Org. Chem. 2017, 13, 1099–1105, doi:10.3762/bjoc.13.109

• flipper probe in the monolayer between 0 and 10 mN/m. It can be concluded that the flipper mechanophores do organize in an amorphous monolayer at low pressure (akin to an ordered liquid phase). High lateral pressures could not be reached with the present set-up. Therefore, further insights were expected

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

• to alkenes is a process of high importance in the manufacture of several market chemicals. The present paper shortly reviews the heterogeneous catalytic systems engineered for this reaction under continuous flow and in the liquid phase. The main contributions appeared in the literature from 1997 up

• to August 2016 are discussed in terms of reactor design. A comparison with batch and industrial processes is provided whenever possible. Keywords: alkynes; heterogeneous catalysis: hydrogenation; flow; liquid-phase; Introduction The catalytic partial hydrogenation of alkynes to alkenes in the

• liquid phase is a reaction of high relevance to the manufacture of a multitude of fine chemicals [1] including pharmaceutical building blocks, agrochemicals, food additives, flavours and fragrances [2][3]. It is also crucial in the bulk polymer industry to achieve the complete elimination of alkynes and

Fast and efficient synthesis of microporous polymer nanomembranes via light-induced click reaction

• Qi An,
• Youssef Hassan,
• Xiaotong Yan,
• Peter Krolla-Sidenstein,
• Tawheed Mohammed,
• Mathias Lang,
• Stefan Bräse and
• Manuel Tsotsalas

Beilstein J. Org. Chem. 2017, 13, 558–563, doi:10.3762/bjoc.13.54

• virtually any support, allows the integration of TYC based CMP materials in functional devices for applications in organic electronics or gas and liquid phase separation. Experimental Chemicals: All chemicals were purchased from commercial sources and used without further purification if not stated

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• -indanone derivative 301 in 55% yield under solid–liquid, phase-transfer catalysis conditions [116]. In this synthesis, 2-cyanomethylbenzaldehyde (300) was reacted with cyclopentenone 239 in the presence of powdered K2CO3 and Aliquat® 336 as a catalyst. (Scheme 84). 3 Construction of the 5- and 6-membered

Self-optimisation and model-based design of experiments for developing a C–H activation flow process

• Alexander Echtermeyer,
• Yehia Amar,
• Jacek Zakrzewski and
• Alexei Lapkin

Beilstein J. Org. Chem. 2017, 13, 150–163, doi:10.3762/bjoc.13.18

• model includes kinetic equations, energy and material balances as well as constitutive equations. A lumped model was created as each reaction segment was assumed to be ideally mixed; thus no excess volume was considered for mixing. As the reaction takes place in a homogeneous liquid phase, and as the

Solution-phase automated synthesis of an α-amino aldehyde as a versatile intermediate

• Hisashi Masui,
• Sae Yosugi,
• Shinichiro Fuse and
• Takashi Takahashi

Beilstein J. Org. Chem. 2017, 13, 106–110, doi:10.3762/bjoc.13.13

• during phase separation is one of the common problems for liquid-phase automated synthesizers that can perform aqueous work-up. ChemKonzert uses a centrifuge instrument to solve this problem: the emulsified mixture is transferred to the separating flask and the phases are separated by centrifugation. The

Solvent-free, visible-light photocatalytic alcohol oxidations applying an organic photocatalyst

• Martin Obst and
• Burkhard König

Beilstein J. Org. Chem. 2016, 12, 2358–2363, doi:10.3762/bjoc.12.229

• liquid phase was observed. In mechanochemistry, the formation of hot spots by friction heating with high local temperatures and the existence of liquid eutectic states are believed to be responsible for chemical transformations [1]. In contrast, in our rod mill apparatus, heating is not induced by