Mechanochemical synthesis of graphene oxide-supported transition metal catalysts for the oxidation of isoeugenol to vanillin

• Ana Franco,
• Sudipta De,
• Alina M. Balu,
• Araceli Garcia and
• Rafael Luque

Beilstein J. Org. Chem. 2017, 13, 1439–1445, doi:10.3762/bjoc.13.141

• were characterized by using several techniques including BET, SEM, TEM, XRD, and IR spectroscopy. N2 adsorption/desorption isotherms of the reduced graphene sample (Figure 1a) can be classified as type IV corresponding to the mesoporous materials. The RGO sample showed a BET surface area of 103 m2 g−1

• with a pore diameter of 39 nm and pore volume of 0.74 cm3 g−1 (Table 1). After the ball milling with metal precursors, the mesoporous structure of RGO was found to be partially collapsed as observed from BET isotherms in Figure 1b and c. BET surface areas of metal supported RGO materials consequently

• mesoporous nature of the RGO can be easily observed from SEM images (Figure 2a and b), whereas metal-supported RGO materials show a smooth surface with decreased crystallinity. TEM images of RGO materials with different thickness show a sheet like morphology with different transparencies (Figure 3). Dark

Mechanochemistry-assisted synthesis of hierarchical porous carbons applied as supercapacitors

• Desirée Leistenschneider,
• Nicolas Jäckel,
• Felix Hippauf,
• Volker Presser and
• Lars Borchardt

Beilstein J. Org. Chem. 2017, 13, 1332–1341, doi:10.3762/bjoc.13.130

• . Keywords: electrochemical energy storage; mesoporous; microporous; solvent-free; supercapacitor; templated carbon; Introduction Porous carbons are key components in many energy and environmentally-relevant applications, such as catalysis [1], gas storage and separation [2][3], and electrochemical energy

• for the synthesis of uniform metal oxide nanoparticles to synthesize a titanium(IV) citrate-based polymer [44][45]. The Pechini method is applicable to synthesize templated mesoporous carbons [46][47][48][49], but has never been utilized for a solvent-free and rapid process based on mechanochemistry

• comparable to other known Kroll carbons [52] and non-doped mesoporous carbons [57]. At a high sweep rate of 500 mV s−1, the shape of the CV, recorded in the organic electrolyte (Figure 7A) remains nearly rectangular, which indicated a high power handling ability. The ion mobility of ionic liquids is lower

Sugar-based micro/mesoporous hypercross-linked polymers with in situ embedded silver nanoparticles for catalytic reduction

• Qing Yin,
• Qi Chen,
• Li-Can Lu and
• Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 1212–1221, doi:10.3762/bjoc.13.120

• to tune the porosity. These obtained polymers exhibit microporous and mesoporous features. The highest Brunauer–Emmett–Teller specific surface area for the resulting polymers was found to be 1220 m2 g−1, and the related carbon dioxide storage capacity was found to be 14.4 wt % at 1.0 bar and 273 K

• SugPOP-2 displays a type I sorption isotherm. A rapid uptake curve reflects the microporous monolayer adsorption tendency at low relative pressure (p/p0 < 0.10). As for SugPOP-1 and SugPOP-3, the significant hysteresis loops (0.50 < p/p0 < 1.00) are consistent with the mesoporous structure. The SSA value

• and 1.35 nm. As for polymers SugPOP-1 and SugPOP-3, their dominant pore size peaks are located around 0.53 and 1.30 nm, associated with mesoporous distribution between 2.2 and 7.0 nm, quantifying their micro/mesoporous features. The main porosity data of the obtained polymers, including SSA, pore

Energy down converting organic fluorophore functionalized mesoporous silica hybrids for monolith-coated light emitting diodes

• Markus Börgardts and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2017, 13, 768–778, doi:10.3762/bjoc.13.76

• Markus Borgardts Thomas J. J. Muller Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany 10.3762/bjoc.13.76 Abstract The covalent attachment of organic fluorophores in mesoporous silica matrices for

• synthesis of mesoporous hybrid materials by postsynthetic grafting to commercially available MCM-41. These individually dye-functionalized hybrid materials are mixed in variable ratios to furnish a powder capable of emitting white light with CIE chromaticity coordinates of x = 0.33, y = 0.33 and an external

• convert the emitted UV light into light with correlated color temperatures of very cold white (41100 K, 10700 K) as well as a greenish white emission with correlated color temperatures of about 5500 K. Keywords: benzofurazane; LED; luminophores; mesoporous silica hybrids; monoliths; Nile red; perylene

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

• , selective liquid phase flow processes for the fine-chemicals synthesis, including partial hydrogenations, usually requires a more intimate contact with the heterogeneous catalyst to be efficient. One example is the so-called "confinement effect" found in mesoporous catalytic materials [77][78]. Catalytic

• ). The preferred choice are mesoporous supports (2–50 nm cavity size), due to the enhanced contact with the reagents because of the high surface area [89][90] and the effective “steric” stabilization of the embedded metal nanoparticle catalysts [91][92]. However, mesoporous catalysts may suffer from pore

• ][108], which addresses the need of both efficient processing (within small pores) and effective mass transport (by macropores) [109][110]. This kind of monolith obtained by spinodal decomposition joins the advantages of high surface area typical of mesoporous material, spanning from 200 to 1200 m2 g−1

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• yields. In 2015, Ghorbani-Choghamarani and co-workers designed a new type of nanocatalyst MCM-41-dzt-Pd through the immobilization of Pd(OAc)2 on the surface of dithizone(dzt)-functionalized mesoporous MCM-41 (Scheme 6) [26]. The developed catalyst was able to convert aryl halides to the corresponding

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

• reaction (TYC); Introduction The synthesis of microporous organic and inorganic materials such as zeolites [1], mesoporous silica [2] as well as metal-organic frameworks (MOF) [3][4] and covalent organic frameworks (COF) [5][6][7] attracted large attention because of their high potential in catalysis, gas

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

Dynamics and interactions of ibuprofen in cyclodextrin nanosponges by solid-state NMR spectroscopy

• Monica Ferro,
• Franca Castiglione,
• Nadia Pastori,
• Carlo Punta,
• Lucio Melone,
• Walter Panzeri,
• Barbara Rossi,
• Francesco Trotta and
• Andrea Mele

Beilstein J. Org. Chem. 2017, 13, 182–194, doi:10.3762/bjoc.13.21

• mesoporous materials CDNS(1:4), CDNS(1:8) in their free form and loaded with ibuprofen sodium salt were prepared and thoroughly characterized using solid-state 1H Fast MAS and 13C CP-MAS NMR spectroscopy. The main conclusions can be summarized as follows: 1. Ibuprofen sodium salt is converted into its acid

Electron-transfer-initiated benzoin- and Stetter-like reactions in packed-bed reactors for process intensification

• Anna Zaghi,
• Daniele Ragno,
• Graziano Di Carmine,
• Carmela De Risi,
• Olga Bortolini,
• Pier Paolo Giovannini,
• Giancarlo Fantin and
• Alessandro Massi

Beilstein J. Org. Chem. 2016, 12, 2719–2730, doi:10.3762/bjoc.12.268

• asymmetric version of acyloin-type reactions was also investigated in our laboratory operating packed-bed bioreactors functionalized with a suitable thiamine diphosphate (ThDP)-dependent enzyme supported on mesoporous silica [17]. Overall, the so far reported umpolung flow processes [12][13][14][15][16][17

Synthesis of three-dimensional porous hyper-crosslinked polymers via thiol–yne reaction

• Mathias Lang,
• Alexandra Schade and
• Stefan Bräse

Beilstein J. Org. Chem. 2016, 12, 2570–2576, doi:10.3762/bjoc.12.252

• adsorption isotherms are depicted in Figure 4. The strong slope of the isotherms at low relative pressures indicates a permanent porous character of the materials. Also the step around p/p0 = 0.5 at desorption isotherms (Supporting Information File 1, Figures S1 and S2) indicates the mesoporous character of

• HCPs 3 and 5. The low-pressure hysteresis is most probable due to swelling effects or ill-connected pores. The pore-size distributions of HCPs 3 and 5 both show a broad distribution in the microporous scale as well as in the mesoporous scale. These findings also point out that both HCPs have amorphous

Diels–Alder reactions in confined spaces: the influence of catalyst structure and the nature of active sites for the retro-Diels–Alder reaction

• Ángel Cantín,
• M. Victoria Gomez and
• Antonio de la Hoz

Beilstein J. Org. Chem. 2016, 12, 2181–2188, doi:10.3762/bjoc.12.208

• effect within the pore and diffusion limitations are discussed. Introduction of Lewis or Brønsted acid sites on the walls of the zeolite strongly increases the reaction rate. However, contrary to what occurs with mesoporous molecular sieves (MCM-41), Beta zeolite does not catalyse the retro-Diels–Alder

• mesoporous material MCM-41 enhances the conversion to the endo-anti-endo isomer as has been shown in a previous work [30]. However, MCM-41 in the form of aluminosilicate that contains Brønsted sites enhances the retro-Diels–Alder reaction increasing the selectivity to the endo-anti-exo isomer. Therefore, the

• framework and extra framework composition of mesoporous materials and zeolite could be used to control the selectivity of the DAR of cyclopentadiene and p-benzoquinone. In the present work, a series of large pore, pure silica zeolites (in which rate enhancement can only occur by spatial confinement) and the

Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

• Dominik Urselmann,
• Konstantin Deilhof,
• Bernhard Mayer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2016, 12, 2055–2064, doi:10.3762/bjoc.12.194

• -transfer characteristics [59][60][61][62][63], as hole-transport materials [64], for applications in mesoporous organo silica hybrid materials [65], and as chromophores in dye-sensitized solar cells [66][67][68]. Furthermore, (oligo)phenothiazines in their native reduced forms display a pronounced ability

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

• Lucie Brulíková,
• Aidan Harrison,
• Marvin J. Miller and
• Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

• Scheme 5). More recently, the method was extended to the mild copper-catalyzed aerobic oxidation of hydroxylamines [48][49][50]. In 2014, the Lykakis group reported the selective oxidation of various arylamines into the corresponding nitrosoarenes through polyoxometalate anions supported on mesoporous

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• ]) dispersed on magnetic mesoporous SiO2/CoFe2O4 and CoFe2O4 nanoparticles [39][40] have been reported as catalysts. In addition, the reaction of ethylene carbonate with methanol for the synthesis of DMC was described in the presence of a mesocellular silica foam (MCF) material [41]. These catalysts are easy

• to recover and recycled by physical separation, washing and drying. A similar approach has been implemented through the design of polymeric ionic liquid (PILs) based systems, such as poly(N-heterocyclic carbene)s and ordered mesoporous resol (OMR) polymers (OMR based on hexamethylenetetramine

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• [bmim]PF6 [247]. Benzoic acids 71a–d, 74 and phenyl esters 75a–d were reported as oxidation byproducts. Sn-containing mesoporous silica nanospheres (Sn-MSNSs) with uniform crater-like mesopores exhibited high activities in the Baeyer–Villiger oxidation of 2-adamantanone (45c) (Scheme 23) [248]. The

• catalysts for the Baeyer–Villiger reaction of cyclohexanone to ε-caprolactone [250]. A mesoporous Mg–Al-mixed oxide showed good catalytic efficiency in the Baeyer–Villiger oxidation of a series of ketones to the corresponding lactones and esters in the presence of diluted aqueous H2O2 and benzonitrile [251

3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

• Wei Li,
• Munechika Otsuka,
• Takehito Kato,
• Yang Wang,
• Takehiko Mori and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2016, 12, 1401–1409, doi:10.3762/bjoc.12.134

• a UV-O3 cleaner (Filgen, Model UV253E) for 20 min. The electron-accepting TiO2 compact layer was spin-coated (1500 rpm for 30 s) from a mildly acidic (after addition of 12 μM HCl) solution of titanium(IV) isopropoxide in anhydrous ethanol and sintered at 120 °C for 10 s. The mesoporous TiO2 layer

• min, and cooled to room temperature. The mesoporous TiO2 films were infiltrated with PbI2 by spin-coating a PbI2 solution in DMF (465 g L−1) at 80 °C. After drying, the films were dipped in a solution of CH3NH3I in 2-propanol (10 g L−1) for 20 s and rinsed with 2-propanol. After drying, the hole

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

• Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

• amines 70 using OSU-6, a novel MCM-41-type hexagonal mesoporous silica, as a catalyst (Scheme 17) [44]. The important advantages of this methodology is that the (3-oxoisoindolin-1-yl)phosphonates 71 are obtained in high yields from benzylic, aliphatic and aromatic amines possessing both, electron

Aggregation behavior of amphiphilic cyclodextrins in a nonpolar solvent: evidence of large-scale structures by atomistic molecular dynamics simulations and solution studies

• Giuseppina Raffaini,
• Fabio Ganazzoli and
• Antonino Mazzaglia

Beilstein J. Org. Chem. 2016, 12, 73–80, doi:10.3762/bjoc.12.8

• conditions. Two fully independent long MD runs of increasingly large systems comprising up to sixty-four molecules suggest the presence of large-scale two-dimensional structures at length scales of more than 10 nm, comprising either relatively uniform membranes or a nano- and mesoporous mesh. Dynamic light

Rhodium, iridium and nickel complexes with a 1,3,5-triphenylbenzene tris-MIC ligand. Study of the electronic properties and catalytic activities

• Carmen Mejuto,
• Beatriz Royo,
• Gregorio Guisado-Barrios and
• Eduardo Peris

Beilstein J. Org. Chem. 2015, 11, 2584–2590, doi:10.3762/bjoc.11.278

• assemblies that include molecular squares and triangles [1][2][3][4][5][6], cylinder-like structures [7][8][9][10][11][12][13], organometallic polymers [14][15][16][17][18][19][20][21][22] and even organometallic mesoporous materials [21][22]. Another interesting feature of this special type of poly-NHCs is

Ru complexes of Hoveyda–Grubbs type immobilized on lamellar zeolites: activity in olefin metathesis reactions

• Hynek Balcar,
• Naděžda Žilková,
• Martin Kubů,
• Michal Mazur,
• Zdeněk Bastl and
• Jiří Čejka

Beilstein J. Org. Chem. 2015, 11, 2087–2096, doi:10.3762/bjoc.11.225

• cationic tags on NHC ligands were linker-free immobilized on the surface of lamellar zeolitic supports (MCM-22, MCM-56, MCM-36) and on mesoporous molecular sieves SBA-15. The activity of prepared hybrid catalysts was tested in olefin metathesis reactions: the activity in ring-closing metathesis of

• immobilization; olefin metathesis; Introduction Immobilization of Ru alkylidene complexes (Grubbs and Hoveyda–Grubbs type catalysts) on siliceous supports represents a successful way to highly active, selective, and reusable metathesis catalysts [1][2][3][4]. Mesoporous molecular sieves (MCM-41, MCM-48, SBA-15

• −) and their immobilization on silica, and mesoporous molecular sieves MCM-41 and SBA-15 [21]. XPS analysis revealed that complexes were attached to the surface by non-covalent interactions and both cationic and anionic parts were present on the surface. The hybrid catalysts prepared were active in RCM

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

• trans-4-hydroxy-L-proline is attractive due to its convenient 4-hydroxy group, a functionality that is ideally placed to function as a handle for further linkage to material supports. The field of such polymer and mesoporous material-supported organocatalysis has now been thoroughly analysed and

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• years the development of new and effective nanostructured catalytic systems dominated the gold-catalyzed approach to A3-coupling. For example, ultrasmall gold(0) nanoparticles embedded in a mesoporous carbon nitride stabilizer [27] proved to be a highly active, selective and recyclable heterogeneous

• ., o-substituted benzaldehydes) gave worse results. Other strengths of the approach are the ultralow catalyst loading (0.236 mol % gold) and the great TON (>400). Periodic mesoporous organosilicas (PMOs), properly functionalized with HS/SO3H [29] or alkylimidazolium [30], were recently used as support

• them on a mesoporous support, i.e., MCM-41. The authors tested them in A3-couplings and found that, although under homogeneous conditions the conversion to the respective propargylamine was higher than under heterogeneous ones, the heterogenized complexes were stable, recyclable for at least six cycles

Silica: An efficient catalyst for one-pot regioselective synthesis of dithioethers

• Samir Kundu,
• Babli Roy and
• Basudeb Basu

Beilstein J. Org. Chem. 2014, 10, 26–33, doi:10.3762/bjoc.10.5

• environmentally friendly and sustainable [32][33][34][35][36]. Mesoporous inorganic oxides, which often facilitate various organic reactions, are considered suitable to promote eco-friendly chemical processes [36]. Organic reactions with a high selectivity under eco-friendly and sustainable conditions are

• possible interactions with thiols is responsible for the notable regioselectivity in the hydrothiolation of allylsulfane. It is known that amorphous or mesoporous silica consists of silanol groups and siloxane bridges that determine its surface properties, and the concentration of these OH groups depends

Continuous-flow Heck synthesis of 4-methoxybiphenyl and methyl 4-methoxycinnamate in supercritical carbon dioxide expanded solvent solutions

• Phei Li Lau,
• Ray W. K. Allen and
• Peter Styring

Beilstein J. Org. Chem. 2013, 9, 2886–2897, doi:10.3762/bjoc.9.325

• they are or after some form of regeneration [17]. The types of heterogeneous catalyst can be further categorised by their support, with examples including polymers, dendrimers, mesoporous materials, zeolites, metal oxides, and carbon. Reactions using palladium supported on mesoporous materials have

• several mesoporous materials [20], and a palladium bipiyridyl complex anchored on nanosized MCM-41 [21]. Furthermore, a myriad of zeolites have been applied in Heck reactions, with examples including: modernite, HY or beta [22][23], montmorillonite [24], layered double hydroxides (LDH) [25]. Heterogeneous