One-pot nucleophilic substitution–double click reactions of biazides leading to functionalized bis(1,2,3-triazole) derivatives

• Hans-Ulrich Reissig and
• Fei Yu

Beilstein J. Org. Chem. 2023, 19, 1399–1407, doi:10.3762/bjoc.19.101

• when benzyl azide (1) and the simple alkyne 2 were combined in the presence of 0.2 equiv of copper(I) iodide in triethylamine as solvent (Scheme 2, reaction 1). After 16 hours at room temperature and chromatographic purification compound 3 was isolated in 79% yield as colorless liquid. Interestingly

Consecutive four-component synthesis of trisubstituted 3-iodoindoles by an alkynylation–cyclization–iodination–alkylation sequence

• Nadia Ledermann,
• Alae-Eddine Moubsit and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2023, 19, 1379–1385, doi:10.3762/bjoc.19.99

• isolation) accounts for an average yield of 55–90% per bond-forming step which can be considered to be relative efficient, also because only a single terminal purification step is required. However, noteworthy, the 3-iodoindoles are sensitive to light and prolonged storage at room temperature, even under

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

Unravelling a trichloroacetic acid-catalyzed cascade access to benzo[f]chromeno[2,3-h]quinoxalinoporphyrins

• Chandra Sekhar Tekuri,
• Pargat Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2023, 19, 1216–1224, doi:10.3762/bjoc.19.89

• . After workup and chromatographic purification, the isolated product was characterized based on spectral data analysis as copper(II) benzo[f]quinoxalinoporphyrin intermediate 17. Further, porphyrin 17 reacted with benzaldehyde and dimedone in chloroform containing 20 mol% trichloroacetic acid at 65 °C to

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• , Germany), and Avantor Performance Materials (Deventer, Netherlands). An in-house Purelab® flex water purification system (Veolia Water Technologies, Celle, Germany), was used in the preparation of deionized water. Fungal material examined The current study specimen was collected by one of the authors C.D

• incubation following the aforementioned established procedures to afford 0.5 g (mycelial) and 1.5 g (supernatant) ethyl acetate extracts for Q6/2 cultures and 3.44 g ethyl acetate extract for rice cultures. Isolation of compounds 1–4 Purification of the rice and Q6/2 media cultures was achieved by using a

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• . Experimental General methods All the chemicals used in synthesis are analytical pure and were used as received without further purification. UV–vis absorption spectra were measured on a UV-2550 Shimadzu spectrophotometer. Fluorescence spectra were recorded with an FS5 spectrofluorometer (Edinburgh instruments

Linker, loading, and reaction scale influence automated glycan assembly

• Marlene C. S. Dal Colle,
• Manuel G. Ricardo,
• Nives Hribernik,
• José Danglad-Flores,
• Peter H. Seeberger and
• Martina Delbianco

Beilstein J. Org. Chem. 2023, 19, 1015–1020, doi:10.3762/bjoc.19.77

• purification steps. Keywords: automated glycan assembly; photocleavable linker; polysaccharides; solid-phase synthesis; Introduction Automated glycan assembly (AGA) is a solid-phase method that enables the rapid synthesis of complex oligo- and polysaccharides from protected monosaccharide building blocks

• cleavage is probably influenced by glycan structure, solubility, and aggregation tendency [26]. Lastly, purification of the protected glycan upon cleavage could be affected by the presence or absence of a linker. L1 or L2 were conjugated to Merrifield resins with initial loadings of 0.5 mmol/g and 1.0 mmol

• Information File 1, section 2.3, module C). The outcome of each AGA experiment was analyzed in terms of: i) HPLC purity based on the chromatogram of the crude sample after AGA and UV cleavage, ii) isolated yield of the target compound after photocleavage and HPLC purification (path A). The syntheses of the α

Five new sesquiterpenoids from agarwood of Aquilaria sinensis

• Hong Zhou,
• Xu-Yang Li,
• Hong-Bin Fang,
• He-Zhong Jiang and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 998–1007, doi:10.3762/bjoc.19.75

• methods were used to purify the extract, such as MCI gel CHP 20, silica gel column, vacuum liquid chromatography, and semi-preparative HPLC purification, to obtain pure compounds. A total of ten compounds, including five new eudesmane-type sesquiterpenoids (1–5), and five known compounds were identified

Synthesis of tetrahydrofuro[3,2-c]pyridines via Pictet–Spengler reaction

• Elena Y. Mendogralo and
• Maxim G. Uchuskin

Beilstein J. Org. Chem. 2023, 19, 991–997, doi:10.3762/bjoc.19.74

• . In most cases, we observed the abundant tarring of the reaction mixture and we could not achieve the full conversion of the starting tetrahydrofuro[3,2-c]pyridine 4a in any experiment. The best results were achieved when HCl in 1,4-dioxane was used (Scheme 3). However, upon isolation and purification

Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

• Dileep Kumar Singh and
• Rajesh Kumar

Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71

• solvent and reaction time. The environmental impacts are manifold, including excessive utilization of organic solvents, high-temperature reactions, the production of hazardous byproducts, and by the use of traditional purification techniques. Therefore, green chemistry methods in Clauson–Kaas synthesis

First synthesis of acylated nitrocyclopropanes

• Kento Iwai,
• Rikiya Kamidate,
• Khimiya Wada,
• Haruyasu Asahara and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2023, 19, 892–900, doi:10.3762/bjoc.19.67

• our study using ethyl acetoacetate (3c) as starting 1,3-dicarbonyl compound according to method b (Scheme 2). After heating an acetonitrile solution of 3c, N-bromosuccinimide, and p-toluenesulfonic acid [7], α-bromoacetoacetate 6c was isolated with a 44% yield after purification of the reaction

• researchers studying organic syntheses using functionalized cyclopropanes. Experimental General All reagents were purchased from commercial sources and used without further purification. 1H and13C NMR spectra were recorded on Bruker DPX-400 and JEOL JMN-ECZ400S spectrometers (400 MHz and 100 MHz, respectively

Asymmetric tandem conjugate addition and reaction with carbocations on acylimidazole Michael acceptors

• Brigita Mudráková,
• Renata Marcia de Figueiredo,
• Jean-Marc Campagne and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 881–888, doi:10.3762/bjoc.19.65

• charges at C-2 of enolates cannot account for the differences in the yields of the trapping products as these are affected by their specific stabilities and issues during isolation and purification. As an additional question that we tried to answer with these calculations was the comparison of the Zn

Facile access to 3-sulfonylquinolines via Knoevenagel condensation/aza-Wittig reaction cascade involving ortho-azidobenzaldehydes and β-ketosulfonamides and sulfones

• Ksenia Malkova,
• Andrey Bubyrev,
• Stanislav Kalinin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 800–807, doi:10.3762/bjoc.19.60

• of the secondary quinoline-3-sulfonamide synthesis, the increase of reagent excesses in relation to ketosulfonamide resulted in the conversion and an increase of the yield as observed by TLC (see GP2 in Supporting Information File 1). Chromatographic purification afforded compounds 5a–q mostly in

Sulfate radical anion-induced benzylic oxidation of N-(arylsulfonyl)benzylamines to N-arylsulfonylimines

• Joydev K. Laha,
• Pankaj Gupta and
• Amitava Hazra

Beilstein J. Org. Chem. 2023, 19, 771–777, doi:10.3762/bjoc.19.57

• purification. Next, in order to determine whether the reaction proceeds via a radical pathway, we performed a control experiment. When substrate 1a was treated with the radical scavenger TEMPO under the optimized reaction conditions, the formation of product 2a was completely suppressed (Scheme 4). This

Honeycomb reactor: a promising device for streamlining aerobic oxidation under continuous-flow conditions

• Masahiro Hosoya,
• Yusuke Saito and
• Yousuke Horiuchi

Beilstein J. Org. Chem. 2023, 19, 752–763, doi:10.3762/bjoc.19.55

• -oxyl (TEMPO) oxidation [8]. TEMPO oxidation, in particular, has been successfully applied on a manufacturing scale as a low-cost and green oxidation method [9]. However, these oxidation processes generally require stoichiometric oxidants, and reduced byproducts must be purged in a purification step

Cassane diterpenoids with α-glucosidase inhibitory activity from the fruits of Pterolobium macropterum

• Sarot Cheenpracha,
• Ratchanaporn Chokchaisiri,
• Lucksagoon Ganranoo,
• Sareeya Bureekaew,
• Thunwadee Limtharakul and
• Surat Laphookhieo

Beilstein J. Org. Chem. 2023, 19, 658–665, doi:10.3762/bjoc.19.47

• eluting with acetone–hexanes (1:19, v/v) to give compound 3 (1.1 mg). Fr.6 (842.0 mg) was chromatographed over silica gel CC eluting with acetone–hexanes (1:19, v/v), and then purified by silica gel CC using 100% CH2Cl2 to afford compound 1 (12.5 mg). Chromatographic purification of Fr.8 (1.2 g) over a

pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene

• Nan Yang,
• Yi-Yan Zhu,
• Wei-Xiu Lin,
• Yi-Long Lu and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45

• of deacetylation greater than 95% (viscosity 100, 200 mPa·s) was purchased from Aladdin. All other reagents and solvents were purchased from Xilong Science as analytical grade and were used without further purification. TBTQ-C6 and TPE-CHO were synthesized and purified according to the previously

• the mixture was heated at 70 °C with stirring for 6–10 h. The resulting mixture was then allowed to stand overnight, and the solvent was removed under reduced pressure to obtain the crude Schiff base as a pale-yellow solid. Without further purification, the Schiff base was dispersed in methanol (60 mL

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• , crop-protecting agents, or advanced materials. Their syntheses often involve numerous reaction steps requiring laborious isolation and intermediate product purification steps. An important strategy for improving syntheses’ effectiveness is the concept of domino reactions, cascade, or tandem reactions

C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

• Grédy Kiala Kinkutu,
• Catherine Louis,
• Myriam Roy,
• Juliette Blanchard and
• Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

• starting material had proved to be the most reactive imine in batch, leading, in the presence of 5 mol % of [Ru3(CO)12] and 3 equivalents of triethoxyvinylsilane in toluene at 150 °C after 5 h, to the alkylated aldehyde 2a with 62% yield, after purification on silica gel (Scheme 2) [21][39]. The flow

• product was recovered for analysis and purification. The NMR yields were calculated on the alkylated imine before purification (based on a starting concentration of furfural of 0.35 M), and the isolated yields corresponded to the C3-alkylated aldehydes after the hydrolysis step that took place during

• purification. The productivity of each system is given in grams per hour (Scheme 7). The optimized flow process conditions could be applied to a variety of vinylsilanes: trialkoxy-, triaryl-, and trialkylvinylsilanes, already used in the batch study [21]. The products 2a–e were obtained in good yields and thus

Direct C2–H alkylation of indoles driven by the photochemical activity of halogen-bonded complexes

• Martina Mamone,
• Giuseppe Gentile,
• Jacopo Dosso,
• Maurizio Prato and
• Giacomo Filippini

Beilstein J. Org. Chem. 2023, 19, 575–581, doi:10.3762/bjoc.19.42

• particular, the use of 2a:1a in a 1:1 ratio resulted in the formation of 3a in 65% yield (entry 12, Table 1). Moreover, we found that employing an excess of 1a (2 equiv) led to the formation of 3a in a 73% yield (entry 13, Table 1). Due to an easier purification of product 3a from the reaction crude by flash

Phenanthridine–pyrene conjugates as fluorescent probes for DNA/RNA and an inactive mutant of dipeptidyl peptidase enzyme

• Josipa Matić,
• Tana Tandarić,
• Marijana Radić Stojković,
• Filip Šupljika,
• Zrinka Karačić,
• Ana Tomašić Paić,
• Lucija Horvat,
• Robert Vianello and
• Lidija-Marija Tumir

Beilstein J. Org. Chem. 2023, 19, 550–565, doi:10.3762/bjoc.19.40

• of phosphates [45][46]. Recombinant human DPP III was obtained by heterologous expression in Escherichia coli and purification according to Špoljarić et al. [47][48]. Stock solutions of Phen-Py-1 and Phen-Py-2 were prepared by dissolving the compounds in DMSO; the total DMSO content was below 1% in

Mechanochemical solid state synthesis of copper(I)/NHC complexes with K₃PO₄

• Ina Remy-Speckmann,
• Birte M. Zimmermann,
• Mahadeb Gorai,
• Martin Lerch and
• Johannes F. Teichert

Beilstein J. Org. Chem. 2023, 19, 440–447, doi:10.3762/bjoc.19.34

• for 4 hours. Afterwards purification included dissolving the crude product in CH2Cl2, filtration over a PTFE syringe filter and concentrating the filtrate under reduced pressure. Employing strong bases such as KHMDS, NaOt-Bu or NaOH did not lead to the desired product (Table 1, entries 7–9). All three

• indicated the presence of 5, but also of unwanted side-products that could not be identified. Purification of 5 from this complex mixture turned out not to be feasible. Further modifications of the milling conditions did not lead to the elimination of these side-products, therefore the experiments with NaH

Asymmetric synthesis of a stereopentade fragment toward latrunculins

• Benjamin Joyeux,
• Antoine Gamet,
• Nicolas Casaretto and
• Bastien Nay

Beilstein J. Org. Chem. 2023, 19, 428–433, doi:10.3762/bjoc.19.32

• 11 in 78% yield (Scheme 1). Due to easier purification, this alcohol was preferred to the aldehyde in our synthetic route, allowing a key stereoselective Krische allylation [21][22] to be envisaged. Applying reported conditions for this allylation – in presence of allyl acetate (10 equiv), [Ir(COD)Cl

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• conditions found by the authors gave the desired macrolide in only 30% yield together with the trans isomer, which was further isomerized to the cis-alkene during purification by column chromatography and light, being the first time that the trans isomer was reported (Scheme 19). Another strategy employed by

Synthesis and reactivity of azole-based iodazinium salts

• Thomas J. Kuczmera,
• Annalena Dietz,
• Andreas Boelke and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2023, 19, 317–324, doi:10.3762/bjoc.19.27

• , the reaction of 4aa in DCE at 50 °C gave the product 5aa in 23% yield (Table 1, entries 1 and 2). A larger amount of TfOH turned out to increase the solubility of the product and therefore impeded the purification process. However, an excess of acid is required for the electrophilic aromatic