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

Continuous flow nitration in miniaturized devices

• Amol A. Kulkarni

Beilstein J. Org. Chem. 2014, 10, 405–424, doi:10.3762/bjoc.10.38

• . [22] demonstrated that high pressure and high temperature conditions, i.e., 900 to 1200 psi and 203–232 °C, using an equimolar nitric acid (70%) gives about 50% yields per pass (Scheme 15). Their reaction assembly consists of a stainless steel preheater tube (outer diameter of 6.24 mm) passed through

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

• homogeneously-catalysed stirred reactions, using custom-built constant volume high pressure autoclaves. Naturally this triggers the question about the possibility of using continuous reactions, an issue which this paper addresses. For continuous flow systems the catalyst stability is important as it must be

Microwave-assisted synthesis of 5,6-dihydroindolo[1,2-a]quinoxaline derivatives through copper-catalyzed intramolecular N-arylation

• Fei Zhao,
• Lei Zhang,
• Hailong Liu,
• Shengbin Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2013, 9, 2463–2469, doi:10.3762/bjoc.9.285

• incorporate the bioactive indole motif may find their pharmaceutical applications after further investigations. Experimental General procedure for the synthesis of 5,6-dihydroindolo[1,2-a]quinoxalines: A high-pressure microwave vessel was loaded with 1 (0.25 mmol, 1.0 equiv), CuI (0.025 mmol, 4.8 mg, 0.1

A combined continuous microflow photochemistry and asymmetric organocatalysis approach for the enantioselective synthesis of tetrahydroquinolines

• Erli Sugiono and
• Magnus Rueping

Beilstein J. Org. Chem. 2013, 9, 2457–2462, doi:10.3762/bjoc.9.284

• placed in a water bath [39]. The light required to perform the reaction is supplied from a high-pressure mercury lamp located outside of the reactor. The lamp consists of a double-jacketed water-cooled pyrex immersion well. The reagents were degassed and introduced into the microreactor using a

Continuous flow photocyclization of stilbenes – scalable synthesis of functionalized phenanthrenes and helicenes

• Quentin Lefebvre,
• Marc Jentsch and
• Magnus Rueping

Beilstein J. Org. Chem. 2013, 9, 1883–1890, doi:10.3762/bjoc.9.221

• tightly wrapped around the water-cooling unit (Duran glass) of a high-pressure mercury lamp (TQ 150, UV-Consulting Peschl). Further optimization and scope was performed with a similar setup using a bigger capillary (FEP, outer/inner diameter 4/2 mm, total volume 24 mL). For the sake of safety and to

Integrating reaction and analysis: investigation of higher-order reactions by cryogenic trapping

• Skrollan Stockinger and
• Oliver Trapp

Beilstein J. Org. Chem. 2013, 9, 1837–1842, doi:10.3762/bjoc.9.214

• cryogenic cooling device is installed directly in the GC oven and connected to the column at the desired column section. Reheating is performed by turning off the cooling device. Commercially available cryogenic cooling devices use compressed gas or high pressure liquids, such as CO2 or N2, to cool the

The first example of the Fischer–Hepp type rearrangement in pyrimidines

• Inga Cikotiene,
• Mantas Jonusis and
• Virginija Jakubkiene

Beilstein J. Org. Chem. 2013, 9, 1819–1825, doi:10.3762/bjoc.9.212

• pyrimidine core toward subsequent substitution. The usage of very harsh reaction conditions (prolonged heating for hours or days, high pressure or microwave irradiation of the reaction mixtures) is required to carry out the second SNAr reaction (Scheme 1) [9][10][11][12][13][14]. In 2012 we published a

Organotellurium-mediated living radical polymerization under photoirradiation by a low-intensity light-emitting diode

• Yasuyuki Nakamura and
• Shigeru Yamago

Beilstein J. Org. Chem. 2013, 9, 1607–1612, doi:10.3762/bjoc.9.183

• thermal conditions to give highly controlled polymers [37]. The polymerization proceeded by irradiation with a weak-intensity light source such as a 60–100 W black lamp or sunlight, but we routinely used a high-intensity light source, namely, a 500 W high pressure Hg lamp, combined with a light cutoff

Efficient continuous-flow synthesis of novel 1,2,3-triazole-substituted β-aminocyclohexanecarboxylic acid derivatives with gram-scale production

• Sándor B. Ötvös,
• Ádám Georgiádes,
• István M. Mándity,
• Lóránd Kiss and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2013, 9, 1508–1516, doi:10.3762/bjoc.9.172

• acid derivatives in a simple and efficient continuous-flow procedure is reported. The 1,3-dipolar cycloaddition reactions were performed with copper powder as a readily accessible Cu(I) source. Initially, high reaction rates were achieved under high-pressure/high-temperature conditions. Subsequently

• regioselectively formed. The high-pressure/high-temperature conditions A led to only medium yields (Table 1, entries 1–4), but under conditions B the yields of triazoles 15 and 16 were excellent, and those of triazoles 17 and 18 were high (76% and 89%, respectively; Table 1, entries 1–4). When the CF reactions of

• azides 13 and 14 with phenylacetylene were repeated under high-pressure/high-temperature conditions with the simultaneous use of additives (100 bar, 100 °C, 0.04 equivalents each of DIEA and HOAc; further conditions were not modified), triazoles 17 and 18 were obtained in very high yields (98% in both

Simple and rapid hydrogenation of p-nitrophenol with aqueous formic acid in catalytic flow reactors

• Rahat Javaid,
• Shin-ichiro Kawasaki,
• Akira Suzuki and
• Toshishige M. Suzuki

Beilstein J. Org. Chem. 2013, 9, 1156–1163, doi:10.3762/bjoc.9.129

• catalyzed with core–shell Au–Pd NPs and Au NPs [23][24][25][26]. Formic acid is another attractive H2 source because it is safe, easy to handle, and requires no high-pressure equipment. Formic acid and formate have been used as effective H2 donors in the catalytic transfer hydrogenation of aromatic nitro

Spectroscopic characterization of photoaccumulated radical anions: a litmus test to evaluate the efficiency of photoinduced electron transfer (PET) processes

• Maurizio Fagnoni,
• Stefano Protti,
• Davide Ravelli and
• Angelo Albini

Beilstein J. Org. Chem. 2013, 9, 800–808, doi:10.3762/bjoc.9.91

• deoxygenated solutions, except where otherwise noted. The examined solutions were irradiated on an optical bench equipped with a 150 W high-pressure mercury lamp, (λIRR = 313 nm). The electrochemical properties of TCB [8][9], DCN [8][9], DCA [8][9], DCP [10], DCP-ME [10], ME [45], PME [28], Et3N [60], iPr3N

4-Pyridylnitrene and 2-pyrazinylcarbene

• Curt Wentrup,
• Ales Reisinger and
• David Kvaskoff

Beilstein J. Org. Chem. 2013, 9, 754–760, doi:10.3762/bjoc.9.85

• Hg lamp (254 nm) or a 1000 W high pressure Hg/Xe lamp equipped with a monochromator and appropriate filters. A water filter was used to remove infrared radiation. Materials 4-Azidopyridine (18) was prepared from 4-bromopyridine and NaN3 in 10% ethanol under reflux for 8 h by adaptation of a

• codeposited with Ar at 25 K. After cooling to 7 K, the spectrum was recorded (Figure S2, Supporting Information File 1): IR (Ar, 7 K) 813, 1271, 1303, 1586, 2100, 2119, 2145, 2280 cm−1. The azide matrix was irradiated with broadband UV light from the high-pressure Xe/Hg lamp, at 290 nm using the monochromator

3-Pyridylnitrene, 2- and 4-pyrimidinylcarbenes, 3-quinolylnitrenes, and 4-quinazolinylcarbenes. Interconversion, ring expansion to diazacycloheptatetraenes, ring opening to nitrile ylides, and ring contraction to cyanopyrroles and cyanoindoles

• Curt Wentrup,
• Nguyen Mong Lan,
• Adelheid Lukosch,
• Pawel Bednarek and
• David Kvaskoff

Beilstein J. Org. Chem. 2013, 9, 743–753, doi:10.3762/bjoc.9.84

• . Photolyses were done through quartz by using a 75 W low pressure Hg lamp (254 nm) or a 1000 W high pressure Hg/Xe lamp equipped with a monochromator and appropriate filters. A water filter was used to remove infrared radiation, and a 7.5% NiSO4 or a NiSO4/CuSO4 solution (7.5 and 2.5%, respectively) to remove