Volatiles from the hypoxylaceous fungi Hypoxylon griseobrunneum and Hypoxylon macrocarpum

• Jan Rinkel,
• Alexander Babczyk,
• Tao Wang,
• Marc Stadler and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2018, 14, 2974–2990, doi:10.3762/bjoc.14.277

• [11][12]. Fungal volatiles can be efficiently analysed by trapping, e.g., on charcoal filters with a closed-loop stripping apparatus (CLSA) that was developed by Grob and Zürcher [13], followed by filter extraction and GC–MS analysis of the obtained headspace extracts [14]. The unambiguous compound

• the charcoal filter traps were removed and extracted with CH2Cl2, followed by GC–MS analysis of the obtained extracts. For both strains a large number of compounds from different compound classes including alcohols, ketones, esters, terpenes and pyrazines were identified. Besides the observed minor

• and under natural light-dark rhythm. The CLSA charcoal filter traps were extracted with CH2Cl2 (50 μL, HPLC grade), followed by analysis of the extracts by GC–MS. GC–MS GC–MS analyses were performed with a 7890A GC coupled to a 5975C inert mass detector (Agilent, Hewlett-Packard Company, Wilmington

Unnatural α-amino ethyl esters from diethyl malonate or ethyl β-bromo-α-hydroxyiminocarboxylate

• Eloi P. Coutant,
• Vincent Hervin,
• Glwadys Gagnot,
• Candice Ford,
• Racha Baatallah and
• Yves L. Janin

Beilstein J. Org. Chem. 2018, 14, 2853–2860, doi:10.3762/bjoc.14.264

• 56 [35] in a 46% overall yield. However, the final oxime reduction turned out to be much improved when using hydrogen and palladium over charcoal in acetic acid. Conclusion As in our previous report [2], the goal of this investigation was to reach a very large variety of racemic α-amino esters. In

Synthesis of unnatural α-amino esters using ethyl nitroacetate and condensation or cycloaddition reactions

• Glwadys Gagnot,
• Vincent Hervin,
• Eloi P. Coutant,
• Sarah Desmons,
• Racha Baatallah,
• Victor Monnot and
• Yves L. Janin

Beilstein J. Org. Chem. 2018, 14, 2846–2852, doi:10.3762/bjoc.14.263

• [21] between two equivalents of ethyl nitroacetate (4) and styrene (15), gave the isoxazoline 16 in a 72% yield as a latent α-amino ester [22][23][24]. From this compound, a reductive cleavage of the isoxazoline ring was initiated using palladium over charcoal and a large excess of ammonium formate in

Synthesis of a tyrosinase inhibitor by consecutive ethenolysis and cross-metathesis of crude cashew nutshell liquid

• Jacqueline Pollini,
• Valentina Bragoni and
• Lukas J. Gooßen

Beilstein J. Org. Chem. 2018, 14, 2737–2744, doi:10.3762/bjoc.14.252

• insignificantly better yields (Table 1, entry 18). It is known that ruthenium metathesis catalysts can be transformed in situ into an active hydrogenation catalyst [37][38]. We, thus added charcoal and methanol to the crude reaction mixture of the cross-metathesis and stirred the reaction for additional 2 h under

• for 6 h. After the reaction was complete, methanol (0.5 mL) and activated charcoal (20.0 mg) were added. The vial was closed with a septum cap, penetrated with a cannula for pressure equilibration and placed into an autoclave. The system was purged twice with H2 (5 bar) and finally pressurized to 5

Assessing the possibilities of designing a unified multistep continuous flow synthesis platform

• Mrityunjay K. Sharma,
• Roopashri B. Acharya,
• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2018, 14, 1917–1936, doi:10.3762/bjoc.14.166

• platform. Schematic representation of a unified platform for the flow synthesis (P1–P14 pumps, PBR packed bed reactor, HE1 heat exchanger, H1 heater, S1 and S2 separator, E1 extractor, TR1–TR4 tubular reactor, CH charcoal, CT1 crystallization tank, T1–T3 tanks, F1 filtration). Layout of a unified synthesis

• intermediates based on approach 1. Components required for the synthesis of the above API’s [pumps (P), reactor (R), heat exchanger (HEx), heater (H), back pressure regulator (BPR), packed/fixed bed reactor (PBR/FBR), separator (S), charcoal adsorption cartridge (CA), liquid–liquid extractor (LLEx)] Sequence of

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

Volatiles from three genome sequenced fungi from the genus Aspergillus

• Jeroen S. Dickschat,
• Ersin Celik and
• Nelson L. Brock

Beilstein J. Org. Chem. 2018, 14, 900–910, doi:10.3762/bjoc.14.77

• grown on medium 129 were collected on charcoal filters with a closed loop stripping apparatus (CLSA) [23]. After solvent extraction (CH2Cl2) of the filters the extracts were analysed by GC–MS and compounds were identified by comparison of the recorded EI mass spectra to mass spectral libraries and of

Volatiles from the xylarialean fungus Hypoxylon invadens

• Jeroen S. Dickschat,
• Tao Wang and
• Marc Stadler

Beilstein J. Org. Chem. 2018, 14, 734–746, doi:10.3762/bjoc.14.62

• and ecologists in volatile secondary metabolites. Volatile natural products can efficiently be captured on charcoal filter traps by using a closed-loop stripping apparatus (CLSA) [6] or on polydimethylsiloxane fibres by application of the solid phase micro-extraction method (SPME) [7], followed by GC

• medium as described by Pažoutová et al. [13]. Analysis of volatiles The volatiles released by H. invadens agar plate cultures were collected using a closed-loop stripping apparatus (CLSA) [6] for 16 to 24 hours at room temperature and under circadian light-dark rhythm. The CLSA charcoal filters were

Volatiles from the tropical ascomycete Daldinia clavata (Hypoxylaceae, Xylariales)

• Tao Wang,
• Kathrin I. Mohr,
• Marc Stadler and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2018, 14, 135–147, doi:10.3762/bjoc.14.9

• by agar plate cultures of Daldinia clavata MUCL 47436 grown on YMG medium were collected on charcoal filter traps by application of a closed-loop stripping apparatus (CLSA) [17]. Dichloromethane extracts of the charged filters were analysed by GC–EIMS, followed by identification of the captured

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• phosphonic acid since the benzyl moieties can be removed by hydrogenolysis (Figure 12). Palladium on charcoal, which is the most used method to prepare phosphonic acid from dibenzyl phosphonate [149], was the catalyst used to prepare the phosphonic acids 33 [150], 34 [151] and 35 [152] (Figure 12). Of note

Nitration of 5,11-dihydroindolo[3,2-b]carbazoles and synthetic applications of their nitro-substituted derivatives

• Roman A. Irgashev,
• Nikita A. Kazin,
• Gennady L. Rusinov and
• Valery N. Charushin

Beilstein J. Org. Chem. 2017, 13, 1396–1406, doi:10.3762/bjoc.13.136

• nitrobenzenes with potassium cyanide as the procedure, affording the ortho-carboxylation of the benzene ring relative to the leaving nitro group and known as von Richter rearrangement [50]. At the same time, reduction of 9a with Na2S2O4, Sn(II) chloride or H2 and Pd (10 wt %) on charcoal catalyst has proved to

Synthesis of novel 13α-estrone derivatives by Sonogashira coupling as potential 17β-HSD1 inhibitors

• Ildikó Bacsa,
• Rebeka Jójárt,
• János Wölfling,
• Gyula Schneider,
• Bianka Edina Herman,
• Mihály Szécsi and
• Erzsébet Mernyák

Beilstein J. Org. Chem. 2017, 13, 1303–1309, doi:10.3762/bjoc.13.126

• phenylacetylene using Pd(OAc)2 and CuI as catalysts [21]. They did not investigate the influence of the nature of the substituent on the phenyl ring of the acetylene on the course of the reactions. They carried out the full saturation of the C≡C bond of the 2-phenethynyl estrone with palladium on charcoal

• -phenethynyl intermediates (8c–11c) with palladium-on-charcoal furnished the 2- or 4-phenethyl-substituted derivatives (16–19). In vitro 17β-HSD1 enzyme inhibition test With the new compounds in hand (8–19, Table 1), we also determined their in vitro inhibitory potencies on human placental 17β-HSD1. In the 3

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

• gas bubble slug length in that case. The optimized conditions showed slightly lower ene selectivity (91.4%) for this type of reactor. Similarly, commercial 5% Pd@charcoal operating in a slurry-type mode resulted in high selectivity in the presence of KOH and 323 K (Table 2, entry 23) [172]. As an

Brønsted acid-mediated cyclization–dehydrosulfonylation/reduction sequences: An easy access to pyrazinoisoquinolines and pyridopyrazines

• Ramana Sreenivasa Rao and
• Chinnasamy Ramaraj Ramanathan

Beilstein J. Org. Chem. 2017, 13, 428–440, doi:10.3762/bjoc.13.46

• using Pd(OH)2 on charcoal/H2 at room temperature followed by coupling the secondary amine with cyclohexanecarboxylic acid using CDI. Praziquantel (1) was obtained in 80% overall yield from 11h (Scheme 8). Conclusion In conclusion, an efficient and alternative synthetic approach has been developed to

• had a septum in the side arm was cooled to room temperature under a steady stream of nitrogen. The flask was charged with a stir bar, 2-benzyl-1,2,3,6,7,11b-hexahydro-4H-pyrazino[2,1-a]isoquinolin-4-one (292 mg, 1 mmol), palladium hydroxide on charcoal (30 mg) and ethyl acetate (15 mL). The reaction

Versatile synthesis of the signaling peptide glorin

• Robert Barnett,
• Daniel Raszkowski,
• Thomas Winckler and
• Pierre Stallforth

Beilstein J. Org. Chem. 2017, 13, 247–250, doi:10.3762/bjoc.13.27

• furnished the protected dipeptides 8a and 8b, respectively. Hydrogenolysis with hydrogen gas and palladium on charcoal gave free amines 9a and 9b. Glorin (1) and glorinamide 2 were then obtained by treating amines 9a and 9b, respectively, with propionic anhydride. The main advantage of our synthesis over

Iodination of carbohydrate-derived 1,2-oxazines to enantiopure 5-iodo-3,6-dihydro-2H-1,2-oxazines and subsequent palladium-catalyzed cross-coupling reactions

• Michal Medvecký,
• Igor Linder,
• Luise Schefzig,
• Hans-Ulrich Reissig and
• Reinhold Zimmer

Beilstein J. Org. Chem. 2016, 12, 2898–2905, doi:10.3762/bjoc.12.289

• therefore briefly examined the reaction of 5-aryl-substituted 1,2-oxazines syn-21 and anti-24 under previously established conditions [53]. The hydrogenolysis of 1,2-oxazine derivative syn-21 in methanol using palladium on charcoal as catalyst afforded the expected α-(3-methoxyphenyl)-substituted γ-amino

• hydrogenolysis processes. As already discussed in previous publications [23][53], the hydrogenolysis of 1,2-oxazines of type 3 with palladium on charcoal very likely starts with a fast N-debenzylation, followed by the reduction of the C-4/C-5 double bond forming the corresponding 3,4,5,6-tetrahydro-2H-1,2

O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside

• Roman Sommer,
• Dirk Hauck,
• Annabelle Varrot,
• Anne Imberty,
• Markus Künzler and
• Alexander Titz

Beilstein J. Org. Chem. 2016, 12, 2828–2833, doi:10.3762/bjoc.12.282

• ) and ≈2 ppm (13C NMR). To prevent acidic degradation, 6 was treated with palladium on charcoal under a hydrogen atmosphere (Table 1, entries 3–5). In MeOH as the solvent, transglycosylation of the seleno glycoside 6 to its methyl O-glycoside was observed (Table 1, entry 3). Changing the solvent to the

A non-canonical peptide synthetase adenylates 3-methyl-2-oxovaleric acid for auriculamide biosynthesis

• Daniel Braga,
• Dirk Hoffmeister and
• Markus Nett

Beilstein J. Org. Chem. 2016, 12, 2766–2770, doi:10.3762/bjoc.12.274

• of ATP on activated charcoal [25]. Both recombinant AulA variants tested against the assumed substrate 3 led to similar turnover (Figure 3a) which demonstrates that the A1 domain is not essential for adenylation of 3 and PCP loading. Further functional characterization was carried out using the

A chiral analog of the bicyclic guanidine TBD: synthesis, structure and Brønsted base catalysis

• Mariano Goldberg,
• Denis Sartakov,
• Jan W. Bats,
• Michael Bolte and
• Michael W. Göbel

Beilstein J. Org. Chem. 2016, 12, 1870–1876, doi:10.3762/bjoc.12.176

• us to assign the R configuration by anomalous dispersion (Supporting Information File 4). This isomer corresponds to the slower running isomer on a Chiralpak IA column. By catalytic hydrogenation with Pd on charcoal the bromo residue of enantiopure 30 was replaced with hydrogen thus converting R

Towards potential nanoparticle contrast agents: Synthesis of new functionalized PEG bisphosphonates

• Souad Kachbi-Khelfallah,
• Maelle Monteil,
• Margery Cortes-Clerget,
• Evelyne Migianu-Griffoni,
• Jean-Luc Pirat,
• Olivier Gager,
• Julia Deschamp and
• Marc Lecouvey

Beilstein J. Org. Chem. 2016, 12, 1366–1371, doi:10.3762/bjoc.12.130

• charcoal in water allowed cleavage of the benzyl moiety and led to the HO-PEG-HMBP 10 in 72% yield (Table 1, entry 14). The ligand 10 permitted to obtain new gadolinium phosphate nanocrystals with luminescent properties [26]. Therefore, we considered the syntheses of other compounds which possess azido or

• -PEG-N3 16a,b were obtained after purification in 72% and 74% yield and characterized by a singlet in 31P [27] NMR at about 17 ppm. Finally, the reduction of the azido compounds 16a,b in the presence of palladium on charcoal and dihydrogen led to the targeted amino-PEG-HMBPs 17a and 17b, respectively

Synthesis of 2-oxindoles via 'transition-metal-free' intramolecular dehydrogenative coupling (IDC) of sp² C–H and sp³ C–H bonds

• Nivesh Kumar,
• Santanu Ghosh,
• Subhajit Bhunia and
• Alakesh Bisai

Beilstein J. Org. Chem. 2016, 12, 1153–1169, doi:10.3762/bjoc.12.111

• decarboxylative protonation on 2-oxindoles bearing an benzylester or para-methoxybenzyl ester at the 3-position in presence of a catalytic amount of Pd on activated charcoal. We have also shown the direct installation of allyl, prenyl, reverse-prenyl, or geranyl groups at the 3-position of 2-oxindole using Pd

• presence of a catalytic amount of Pd on activated charcoal under hydrogenolysis. Thus, we explored the substrate scope using β-N-arylamido benzyl ester or β-N-arylamido p-methoxybenzyl ester as starting materials for the oxidative coupling reaction shown in Figure 2. Towards this end, β-N-aryl amido

• effort towards the synthesis of 3-alkylated or arylated 2-oxindoles. Towards this, we subjected to react, the oxidative coupling products (±)-6, (±)-12c and d having benzyl (Bn) or p-methoxybenzyl (PMB) esters with a catalytic amount of Pd on activated charcoal (10% Pd on charcoal) under atmospheric

Art, auto-mechanics, and supramolecular chemistry. A merging of hobbies and career

• Eric V. Anslyn

Beilstein J. Org. Chem. 2016, 12, 362–376, doi:10.3762/bjoc.12.40

• . Earliest inspirations My father, Samuel Anslyn Jr., was an industrial artist. In World War II and later he worked as an artist rendering exquisitely detailed charcoal sketches, and airbrush mock-ups of airplane and ram-jet parts. Before becoming an art and drafting teacher at a Glendale Community College

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

• 2006 Lipshutz et al. demonstrated that the impregnation of charcoal with an aqueous solution of Cu(NO3)2 in US bath, gave copper nanoparticles: an efficient catalyst in CuAAC [58]. Besides the easier work-up of heterogeneous catalysis, Cu(I)/charcoal also gave a higher yield compared to soluble CuSO4

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

• is important to note that in this study we focused on establishing the scope of this heterogenisation method, i.e., by testing a wide number of potential supports, such as silica, alumina, charcoal, iron powder, as well as biocompatible wool and paper, and by examining different catalyst removal

• industrial potential [50]. Preparation of high-surface 8 by precipitation and by immobilisation on charcoal, silica, alumina, cotton and paper and the application of such materials in catalysis Microcrystalline 8 showed only marginal activity in olefin metathesis when applied as a suspension in toluene. This

• was ascribed to the low surface area of this material. Therefore, we decided to deposit 8 on a solid support characterised by a high surface. The initially chosen support for the catalyst deposition was activated carbon (charcoal, C*), which is known to have a high surface area [51]. Addition of C* to

Synthetic strategies for the fluorescent labeling of epichlorohydrin-branched cyclodextrin polymers

• Milo Malanga,
• Mihály Bálint,
• István Puskás,
• Kata Tuza,
• Tamás Sohajda,
• László Jicsinszky,
• Lajos Szente and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2014, 10, 3007–3018, doi:10.3762/bjoc.10.319

• technique due to the strong interaction between the stationary phase and the polymer. In this case liquid/liquid extraction is necessary to remove the bulk of the dye-related byproducts, the hot charcoal treatment can decrease their amounts and the final dialysis step (or ultrafiltration) can further reduce