Diels–Alder reactions of myrcene using intensified continuous-flow reactors

• Christian H. Hornung,
• Miguel Á. Álvarez-Diéguez,
• Thomas M. Kohl and
• John Tsanaktsidis

Beilstein J. Org. Chem. 2017, 13, 120–126, doi:10.3762/bjoc.13.15

• flow reactor. The reaction was conducted at 160 °C. The product, a transparent, faintly yellow solution, was collected at the reactor outlet, after passing through a stainless steel Swagelok® R3A series adjustable high pressure valve. This valve was used as a back pressure regulator, in order to set

A new protocol for the synthesis of 4,7,12,15-tetrachloro[2.2]paracyclophane

• Donghui Pan,
• Yanbin Wang and
• Guomin Xiao

Beilstein J. Org. Chem. 2016, 12, 2443–2449, doi:10.3762/bjoc.12.237

• benzyl brominated product was obtained. This could be explained by the deactivating effect of the nitro group [16]. Therefore, a 100 W high pressure mercury lamp (‘solar’ light) was used to increase the formation of bromide radical in the repeated bromination experiment of 9. On this occasion the yield

Superelectrophilic activation of 5-hydroxymethylfurfural and 2,5-diformylfuran: organic synthesis based on biomass-derived products

• Dmitry S. Ryabukhin,
• Dmitry N. Zakusilo,
• Mikhail O. Kompanets,
• Anton A.Tarakanov,
• Irina A. Boyarskaya,
• Tatiana O. Artamonova,
• Mikhail A. Khohodorkovskiy,
• Iosyp O. Opeida and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2016, 12, 2125–2135, doi:10.3762/bjoc.12.202

• temperature for 1–24 h gives rise to 5-arylmethylfurfurals (yields of 17–91%) and 2-arylmethyl-5-(diarylmethyl)furans (yields of 10–37%). The formation of these two types of reaction products depends on the nucleophilicity of the arene. The same reactions under the action of acidic zeolites H-USY in high

• pressure tubes at 130 °C for 1 h result in the formation of only 5-arylmethylfurfurals (yields of 45–79%). 2,5-Diformylfuran (2,5-DFF) in the reaction with arenes under the action of AlBr3 at room temperature for 1 h leads to 5-(diarylmethyl)furfurals (yields of 51–90%). The reactive protonated species of

A flow reactor setup for photochemistry of biphasic gas/liquid reactions

• Josef Schachtner,
• Patrick Bayer and
• Axel Jacobi von Wangelin

Beilstein J. Org. Chem. 2016, 12, 1798–1811, doi:10.3762/bjoc.12.170

• ], multiphasic reactions including solid-phase protocols [18], addition of gaseous reagents [19], high-pressure conditions [20], cascade conversions without intermediate work-up operations [21], as well as thin film, falling film [22], micro-channel [23], and tube-in-tube reactors [24][25] for reactions between

• are suitable for most applications. A low dead volume and a high pressure resistance are key characteristics of T mixers. However, careful optimization of the internal size, shape, and dead volume of the T-mixer directly affects the local concentrations of the reagents and thus can have dramatic

Flow carbonylation of sterically hindered ortho-substituted iodoarenes

• Carl J. Mallia,
• Gary C. Walter and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2016, 12, 1503–1511, doi:10.3762/bjoc.12.147

• -up, conducted in the departmental high pressure lab (HPL), was set up in a Parr autoclave using carbon monoxide at 15 bar and 110 °C for 2 hours. After purification, a yield of 87% for product 5 was obtained. This compares well with the flow protocol, however, the reaction “processing” time is in

• reality much longer due to the long cooling and heating times (4 h 15 min “processing” time, see experimental section in Supporting Information File 1 for more details). Also, the time required due to the extra precautionary measures needed when high pressure laboratory equipment is used means that the

• Information File 1 for full experimental data. General notes Warning Carbon monoxide is highly toxic and extremely flammable gas. All reactions were carried out in well ventilated fume cupboards and carbon monoxide detectors were continuously used thought the process. High pressure lab facilities were used

Separation and identification of indene–C₇₀ bisadduct isomers

• Bolong Zhang,
• Jegadesan Subbiah,
• David J. Jones and
• Wallace W. H. Wong

Beilstein J. Org. Chem. 2016, 12, 903–911, doi:10.3762/bjoc.12.88

• device performance. In a previous communication [9], an isomer of IC70BA was obtained by chromatographic separation using both flash chromatography and high pressure liquid chromatography (HPLC). X-ray crystallography revealed that this sample contained the 2 o’clock-B isomer (Figure 2b). This material

(Thio)urea-mediated synthesis of functionalized six-membered rings with multiple chiral centers

• Giorgos Koutoulogenis,
• Nikolaos Kaplaneris and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2016, 12, 462–495, doi:10.3762/bjoc.12.48

• malonates 6, to obtain 3,4,4-trisubstituted cyclohexanones 7 [17]. It is noted that the organocatalyst employed is the same with the previous example, catalyst 4. Furthermore, this reaction is taking place in the presence of PPY and high pressure was utilized. The authors proposed that PPY deprotonates the

• aminoaldehyde product. Finally, the N-protected aminoaldehyde product can now be cyclized under the reactions’ conditions. Another stereoselective reaction was attempted by Kotsuki’s group presenting an organocatalytic hetero-Diels–Alder reaction between isatin 229 with substituted diene 230. High pressure had

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• CD, the reaction mechanism, environmental concerns, and the reaction scale are only a part of all the information required to design successful preparations. (a) Multihorn-flow US reactor, (b) Cavitational turbine, (c) Pilot-scale BM, (d) High-pressure MW reactor. Trends in CD papers and CD use in

Effective immobilisation of a metathesis catalyst bearing an ammonium-tagged NHC ligand on various solid supports

• Krzysztof Skowerski,
• Jacek Białecki,
• Stefan J. Czarnocki,
• Karolina Żukowska and
• Karol Grela

Beilstein J. Org. Chem. 2016, 12, 5–15, doi:10.3762/bjoc.12.2

• literature that ruthenium residues, present in the reaction mixture after olefin metathesis, can serve as an in situ homogeneous catalyst for high pressure hydrogenation of the newly formed C–C double bonds [57][58][59][60][61]. On this basis, we assumed that the ruthenium complex impregnated on carbon 8-C

• % isolated yield and was found to contain only 5.7 ppm of residual ruthenium after simple filtration (Scheme 4). It should be emphasised that this result was obtained without application of high pressure of hydrogen gas, and did not require any specific equipment. Conclusion In summary, we have reported on

Synthesis of α,β-unsaturated esters via a chemo-enzymatic chain elongation approach by combining carboxylic acid reduction and Wittig reaction

• Yitao Duan,
• Peiyuan Yao,
• Yuncheng Du,
• Jinhui Feng,
• Qiaqing Wu and
• Dunming Zhu

Beilstein J. Org. Chem. 2015, 11, 2245–2251, doi:10.3762/bjoc.11.243

• 4 °C, and disrupted by high pressure homogenizer after re-suspension in binding buffer (20 mM sodium phosphate buffer, 0.5 M NaCl, 20 mM imidazole, pH 7.4). His-CAR or His-PPTase protein in the supernatant fraction was collected from the crude cell lysate by centrifugation at 12 000g for 20 min

Cross metathesis of unsaturated epoxides for the synthesis of polyfunctional building blocks

• Meriem K. Abderrezak,
• Kristýna Šichová,
• Nancy Dominguez-Boblett,
• Antoine Dupé,
• Zahia Kabouche,
• Christian Bruneau and
• Cédric Fischmeister

Beilstein J. Org. Chem. 2015, 11, 1876–1880, doi:10.3762/bjoc.11.201

• -consuming work-up procedures [41]. To the best of our knowledge, such a tandem procedure has not been applied to an epoxide containing olefin. Compound 2 was prepared as described here above (Scheme 1) and the reaction mixture was directly transferred into a high pressure reactor without any work-up

Cross-metathesis of polynorbornene with polyoctenamer: a kinetic study

• Yulia I. Denisova,
• Maria L. Gringolts,
• Alexander S. Peregudov,
• Liya B. Krentsel,
• Ekaterina A. Litmanovich,
• Arkadiy D. Litmanovich,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2015, 11, 1796–1808, doi:10.3762/bjoc.11.195

• argon flow of 70 mL/min in the range from −100 °C to 100 °C. The molar mass of the polymers was determined by GPC on a Waters high pressure chromatograph equipped with a refractometric detector and Microgel mix 1–5 μm 300 × 7.8 mm Waters Styragel HR 5E column, with toluene for PNB and NB-COE copolymers

Grubbs–Hoveyda type catalysts bearing a dicationic N-heterocyclic carbene for biphasic olefin metathesis reactions in ionic liquids

• Maximilian Koy,
• Hagen J. Altmann,
• Benjamin Autenrieth,
• Wolfgang Frey and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2015, 11, 1632–1638, doi:10.3762/bjoc.11.178

• ). ICP–OES measurements: The corresponding polymer (20 mg) was added to high-pressure Teflon tubes. Digestion was performed under microwave conditions using aqua regia (10 mL). The mixture was cooled to room temperature, diluted with deionized water (approx. 40 mL), filtered and subjected to ICP–OES for

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• treated with LAH to generate diol 266 (72–92%). The dehydration of diol 266 with pyridinium p-toluenesulfonate in benzene gave diolefin 267. [2 + 2] Photocycloaddition of diolefin 267 was carried out by irradiation with a 400 W high-pressure Hg lamp (Pyrex filter) in benzene for 26–92 h. After evaporation

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

• in flow Another example in which flow chemical synthesis was used as the key step in an industrial setting was reported by scientists from Eli Lilly (USA) in 2012. An asymmetric high-pressure hydrogenation towards LY500307 (82) [75] was demonstrated (Scheme 14). As this campaign aimed to produce the

• key intermediate 83 at pilot-scale, a flow-based asymmetric hydrogenation was chosen as an economically more viable option compared to establishing a high-pressure batch process. As depicted in Scheme 14, solutions of the substrate 84 and a zinc triflate additive were combined with the rhodium

Hetero-Diels–Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles

• Grzegorz Mlostoń,
• Paulina Grzelak,
• Maciej Mikina,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2015, 11, 576–582, doi:10.3762/bjoc.11.63

• , University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland 10.3762/bjoc.11.63 Abstract Selected hetaryl and aryl thioketones react with acetylenecarboxylates under thermal conditions in the presence of LiClO4 or, alternatively, under high-pressure conditions (5 kbar) at room temperature

• sulfones. Keywords: dimethyl acetylenedicarboxylate (DMAD); hetero-Diels–Alder reactions; high pressure reactions; methyl propiolate; thioketones; thiopyrans; Introduction A series of recent publications evidence that, in contrast to earlier opinions, thioketones are useful building blocks for the

• examine the reactions of diverse hetaryl thioketones with both 2a and methyl propiolate (2b). Moreover, along with standard procedures, the high-pressure technique was applied. Finally, selected examples of the obtained polycyclic 2H-thiopyrans were oxidized to give the corresponding sulfones. Results and

Morita–Baylis–Hillman reaction of acrylamide with isatin derivatives

• Radhey M. Singh,
• Kishor Chandra Bharadwaj and
• Dharmendra Kumar Tiwari

Beilstein J. Org. Chem. 2014, 10, 2975–2980, doi:10.3762/bjoc.10.315

• with aldehydes, the reaction with ketones is somewhat problematic. For a successful reaction to occur, the ketones require activation either by the presence of an α-activating group [9][10], the use of Lewis acid [11] or application of high pressure [12]. Similarly, in the case of activated alkenes

Detonation nanodiamonds biofunctionalization and immobilization to titanium alloy surfaces as first steps towards medical application

• Juliana P. L. Gonçalves,
• Afnan Q. Shaikh,
• Manuela Reitzig,
• Daria A. Kovalenko,
• Jan Michael,
• René Beutner,
• Gianaurelio Cuniberti,
• Dieter Scharnweber and
• Jörg Opitz

Beilstein J. Org. Chem. 2014, 10, 2765–2773, doi:10.3762/bjoc.10.293

• to lattice defects without photobleaching, obtained during the high pressure high temperature process. Further the carbon surface and its various functional groups in consequence of the synthesis, facilitate additional chemical and biological modification. In this work we present our recent results

Electrocarboxylation: towards sustainable and efficient synthesis of valuable carboxylic acids

• Roman Matthessen,
• Jan Fransaer,
• Koen Binnemans and
• Dirk E. De Vos

Beilstein J. Org. Chem. 2014, 10, 2484–2500, doi:10.3762/bjoc.10.260

• difficulty operating in organic solvents and under high pressure conditions, limiting operational conditions [44]. The anodic oxidation of more reduction stable tetraalkylammonium salts is another approach compatible with non-sacrificial anodes (Scheme 6c). Here, the released tetraalkylammonium cations

Phosphinocyclodextrins as confining units for catalytic metal centres. Applications to carbon–carbon bond forming reactions

• Matthieu Jouffroy,
• Rafael Gramage-Doria,
• David Sémeril,
• Dominique Armspach,
• Dominique Matt,
• Werner Oberhauser and
• Loïc Toupet

Beilstein J. Org. Chem. 2014, 10, 2388–2405, doi:10.3762/bjoc.10.249

• candidates for hydroformylation studies. High-pressure NMR studies Upon subjecting complex 13 to a syngas (1:1 CO/H2 mixture) pressure of 40 bar at 80 °C in toluene-d8 (Scheme 7), the only species that was detected by high-pressure NMR and IR spectroscopy [44] was complex trans-[RhH(HUGPHOS-2)(CO)3] (14

• result (Table 2, entry 12) was obtained at room temperature and high pressure, the ee value and the proportion of branched aldehyde reaching then 95% and 98.3%, respectively. Clearly, isoregioselectivity increases concomitantly with enantioselectivity contrary to what is generally observed [37], probably

• . Ow stands for water molecules. Ruthenium complexes 7 and 8 in Newman projection along the Ru–P bond. Titration of HUGPHOS-1 with [Rh(CO)2Cl]2 at 25 °C. High pressure NMR spectra of 13 under CO/H2 (1:1) recorded in toluene-d8 (at various temperatures and pressures), showing its conversion into trans

A new charge-tagged proline-based organocatalyst for mechanistic studies using electrospray mass spectrometry

• J. Alexander Willms,
• Rita Beel,
• Martin L. Schmidt,
• Christian Mundt and
• Marianne Engeser

Beilstein J. Org. Chem. 2014, 10, 2027–2037, doi:10.3762/bjoc.10.211

• cyclotron resonance (FT–ICR) mass spectrometer with a 7.05 T magnet and an Apollo electrospray (ESI) ion source equipped with an off-axis 70° spray needle. Analyte solutions were fed into high pressure PEEK mixing tees from Alltech and then introduced into the ion source with a single- and a dual syringe

Photo, thermal and chemical degradation of riboflavin

• Muhammad Ali Sheraz,
• Sadia Hafeez Kazi,
• Sofia Ahmed,
• Zubair Anwar and
• Iqbal Ahmad

Beilstein J. Org. Chem. 2014, 10, 1999–2012, doi:10.3762/bjoc.10.208

• (medium pressure mercury vapor lamp, 125 W), i.e., 2.19 ± 0.12 × 1018 quanta s−1 as compared to the visible sources (high pressure mercury vapor fluorescent lamp, 125 W and tungsten lamp, 150 W), i.e., 1.14 ± 0.10 × 1017 and 1.06 ± 0.11 × 1016 quanta s−1, respectively [24][26]. Previously it was reported

• change was observed whereas color continued to change in the synthetic samples and become more discolored upon continuous irradiation. An increase in color change in both powders was noted when the drug substance was compressed with an IR press at high pressure prior to exposure [73]. In the case of

• is not affected by heating processes like hot air convection, infrared, high-pressure steam, or microwave during cooking [58] as well as to milk pasteurization [156]. Almost comparable first-order rate constants of 7.1 × 10−3, 7.0 × 10−3, and 6.6 × 10−3 min−1 were obtained for the thermal degradation

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• analogue (approximately 10% over the same conditions) [49]. The high pressure viscosity data in this study is combined with high pressure SANS (HP-SANS) characterizations which confirmed the presence of anisotropic microemulsion aggregates, or rod-like micelles, within samples containing Ni2+ and Co2

Comparing kinetic profiles between bifunctional and binary type of Zn(salen)-based catalysts for organic carbonate formation

• Carmen Martín and
• Arjan W. Kleij

Beilstein J. Org. Chem. 2014, 10, 1817–1825, doi:10.3762/bjoc.10.191

• . Marta Giménez Pedrós and Dr. Yvette Mata Campaña for assistance with high pressure experiments.

Polyglycerol-functionalized nanodiamond as a platform for gene delivery: Derivatization, characterization, and hybridization with DNA

• Li Zhao,
• Yuki Nakae,
• Hongmei Qin,
• Tadamasa Ito,
• Takahide Kimura,
• Hideto Kojima,
• Lawrence Chan and
• Naoki Komatsu

Beilstein J. Org. Chem. 2014, 10, 707–713, doi:10.3762/bjoc.10.64

• potential of ND-PG-BPP as vectors for gene delivery. Experimental Materials and instruments All the reagents and solvents used for the synthesis were employed as received. ND with 50 nm median diameter (ND50), prepared from high-pressure-high-temperature (HPHT) bulk diamond, was kindly provided by Tomei