NHC-catalysed highly selective aerobic oxidation of nonactivated aldehydes

• Lennart Möhlmann,
• Stefan Ludwig and
• Siegfried Blechert

Beilstein J. Org. Chem. 2013, 9, 602–607, doi:10.3762/bjoc.9.65

• of carbinols to aldehydes or ketones using oxygen, visible light and mesoporous graphitic carbon nitride (mpg-C3N4) polymer as a metal-free photocatalyst [4]. As an extension of this method we were interested in a consecutive organocatalytic process using an N-heterocyclic carbene (NHC) together with

The β-cyclodextrin/benzene complex and its hydrogen bonds – a theoretical study using molecular dynamics, quantum mechanics and COSMO-RS

• Jutta Erika Helga Köhler and
• Nicole Grczelschak-Mick

Beilstein J. Org. Chem. 2013, 9, 118–134, doi:10.3762/bjoc.9.15

• chains of proteins [6], to size control of the electrostatic self assembly of nanoparticles [7]. Also a pH-controlled release of many cyclodextrins in long stacks on polymers, such as polyrotaxanes, combined with mesoporous silica particles was observed [8]. Complex formation with solvent molecules can

Iron-containing mesoporous aluminosilicate catalyzed direct alkenylation of phenols: Facile synthesis of 1,1-diarylalkenes

• Satyajit Haldar and
• Subratanath Koner

Beilstein J. Org. Chem. 2013, 9, 49–55, doi:10.3762/bjoc.9.6

• conditions”. On further exploration of the use of iron-based mesoporous aluminosilicate catalyst in the direct alkenylation of arenes, we have succeeded in vinylation of various phenols with different phenylacetylenes. In this paper we report a convenient method for the alkenylation of phenols with aryl

• -substituted alkynes under mild conditions. Results and Discussion MCM-41 and Al-MCM-41 were prepared according to the procedure described in our earlier report [33]. The incorporation of iron(III) was achieved in a similar way [33]. The mesoporous patterns of MCM-41, Al-MCM-41 and Fe-Al-MCM-41 were

• alumina support “Al-MCM-41” itself was used as catalyst, the conversion recorded was only 2% (Table 2, entry 7). The aluminium-free pure mesoporous silica, MCM-41, displayed no catalytic activity, as expected (Table 2, entry 8). This clearly indicates that the presence of iron in the catalyst Fe-Al-MCM-41

Reactions of salicylaldehyde and enolates or their equivalents: versatile synthetic routes to chromane derivatives

• Ishmael B. Masesane and
• Zelalem Yibralign Desta

Beilstein J. Org. Chem. 2012, 8, 2166–2175, doi:10.3762/bjoc.8.244

• ]. Heravi and co-workers, on the other hand, used a mesoporous molecular sieves (MCM-41)-catalyzed Knoevenagel reaction of salicylaldehyde (5) and malononitrile (20) to give 2-iminochromene 21 in 94% yield (Scheme 15) [33]. The generality of Haravi’s method was demonstrated by the reactions of 3-hydroxy-, 4

Self-assembled organic–inorganic magnetic hybrid adsorbent ferrite based on cyclodextrin nanoparticles

• Ângelo M. L. Denadai,
• Frederico B. De Sousa,
• Joel J. Passos,
• Fernando C. Guatimosim,
• Kirla D. Barbosa,
• Ana E. Burgos,
• Fernando Castro de Oliveira,
• Jeann C. da Silva,
• Bernardo R. A. Neves,
• Nelcy D. S. Mohallem and
• Rubén D. Sinisterra

Beilstein J. Org. Chem. 2012, 8, 1867–1876, doi:10.3762/bjoc.8.215

• able to adsorb gas at 115 cm3 g−1, showing a type IV isotherm by (Brunauer, Deming, Deming, and Teller) BDDT classification [33], which is characteristic of mesoporous materials, and its hysteresis loop closed at p/p0 = 0.2. Adsorbing capacity for the Fe-Ni/Zn/βCD was 125 cm3 of gas per gram

Pseudo five-component synthesis of 2,5-di(hetero)arylthiophenes via a one-pot Sonogashira–Glaser cyclization sequence

• Dominik Urselmann,
• Dragutin Antovic and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1499–1503, doi:10.3762/bjoc.7.174

• strikingly simple methodology is highly practical and leads to a straightforward protocol for the preparation of the title compounds. Studies addressing more-sophisticated 2,5-disubstituted thiophenes for surface modification and also mesoporous hybrid materials are currently underway. Experimental 2c: An 80

Scaling up of continuous-flow, microwave-assisted, organic reactions by varying the size of Pd-functionalized catalytic monoliths

• Ping He,
• Stephen J. Haswell,
• Paul D. I. Fletcher,
• Stephen M. Kelly and
• Andrew Mansfield

Beilstein J. Org. Chem. 2011, 7, 1150–1157, doi:10.3762/bjoc.7.133

• flow characteristics when coupled with the highly controlled surface properties associated with the formation of nano-, micro- and mesoporous structures, and they therefore represent ideal supports for reagents and catalysts where contact time and temperature can be spatially and temporally mediated

• [24] the measurements obtained from N2 adsorption and desorption isotherms indicate a type H2 hysteresis, which is consistent with the disordered mesoporous structure seen in the micrograph shown in Figure 1 (also see Supporting Information File 1, Figure S2) Effect of Pd precursor on the activity of

Effects of anion complexation on the photoreactivity of bisureido- and bisthioureido-substituted dibenzobarrelene derivatives

• Heiko Ihmels and
• Jia Luo

Beilstein J. Org. Chem. 2011, 7, 278–289, doi:10.3762/bjoc.7.37

• unit. Stereoselective DPM rearrangements of dibenzobarrelene derivatives have been reported in special media, such as chiral mesoporous silica [31] or ionic-liquids [32]; however, most examples for stereoselective DPM rearrangements of dibenzobarrelene derivatives have been observed in the solid-state

Hoveyda–Grubbs type metathesis catalyst immobilized on mesoporous molecular sieves MCM-41 and SBA-15

• Hynek Balcar,
• Tushar Shinde,
• Naděžda Žilková and
• Zdeněk Bastl

Beilstein J. Org. Chem. 2011, 7, 22–28, doi:10.3762/bjoc.7.4

• Hynek Balcar Tushar Shinde Nadezda Zilkova Zdenek Bastl J. Heyrovský Institute of Physical Chemistry of AS CR, v.v.i, Dolejškova 3, 182 23 Prague 8, Czech Republic 10.3762/bjoc.7.4 Abstract A commercially available Hoveyda–Grubbs type catalyst (RC303 Zhannan Pharma) was immobilized on mesoporous

• : alkene metathesis; catalyst immobilization; hybrid catalysts; mesoporous molecular sieves; Ru–alkylidene complexes; Introduction Ru–alkylidene complexes (Grubbs and Hoveyda–Grubbs catalysts, 1 and 2, respectively, Figure 1) belong to the most active and frequently used metathesis catalysts. These

• unclear. The aims of this paper are the following: to report the immobilization of the Hoveyda–Grubbs type catalyst 3 (Figure 2, Zhan catalyst-1B) on mesoporous molecular sieves SBA-15 and MCM-41 as supports with this simple immobilization method; to describe the activity and stability of heterogeneous

Stereoselectivity of supported alkene metathesis catalysts: a goal and a tool to characterize active sites

• Christophe Copéret

Beilstein J. Org. Chem. 2011, 7, 13–21, doi:10.3762/bjoc.7.3

• –inorganic materials [43], where surface functionalities such as typical organic ligands are perfectly distributed within the pore networks of a mesoporous silica. For other approaches used to prepare supported homogeneous catalysts, see the reviews [44][45][46]. Selective grafting of organometallic

From discovery to production: Scale- out of continuous flow meso reactors

• Peter Styring and
• Ana I. R. Parracho

Beilstein J. Org. Chem. 2009, 5, No. 29, doi:10.3762/bjoc.5.29

• the reagent solution flowed using a syringe pump [8][9][13]. This is termed as meso reactor as it shows many of the benefits of a micro reactor but at a slightly larger volume. Using a mesoporous version of the catalyst the rate of reaction was enhanced over 3000 times which meant that useful