Total synthesis of grayanane natural products

• Nicolas Fay,
• Rémi Blieck,
• Cyrille Kouklovsky and
• Aurélien de la Torre

Beilstein J. Org. Chem. 2022, 18, 1707–1719, doi:10.3762/bjoc.18.181

• diastereoselectivity in 58% on a 3 g scale. Subsequently, vinyl halide 48 was converted to diene 50 by Suzuki coupling with potassium vinyltrifluoroborate (49) in 90% yield (Scheme 8). The C7–C8 bond formation from a bridgehead carbocation was a real challenge to close the 7-membered ring. To achieve this, the

Synthesis of (−)-halichonic acid and (−)-halichonic acid B

• Keith P. Reber and
• Emma L. Niner

Beilstein J. Org. Chem. 2022, 18, 1629–1635, doi:10.3762/bjoc.18.174

• ] and subsequently hydrolyzed to give 4), we added excess DIBAL and allowed the reaction mixture to stir at room temperature for an additional 24 hours. Upon quenching the reaction with a saturated aqueous solution of potassium sodium tartrate (Rochelle’s salt), we were astonished to observe the clean

A new route for the synthesis of 1-deazaguanine and 1-deazahypoxanthine

• Raphael Bereiter,
• Marco Oberlechner and
• Ronald Micura

Beilstein J. Org. Chem. 2022, 18, 1617–1624, doi:10.3762/bjoc.18.172

• two options for the generation of 4-ethoxy-2,3,6-triaminopyridine (9). One possibility comprised the deprotection of the dicarbamate 5 with potassium hydroxide giving the diamine 6, followed by azo coupling with the diazonium salt obtained from aniline and sodium nitrite to give azo compound 7

Formal total synthesis of macarpine via a Au(I)-catalyzed 6-endo-dig cycloisomerization strategy

• Jiayue Fu,
• Bingbing Li,
• Zefang Zhou,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2022, 18, 1589–1595, doi:10.3762/bjoc.18.169

• deprotection of the silyl group was accomplished in the presence of potassium carbonate (K2CO3) and methanol to provide the terminal alkyne 5 in 96% yield in two steps. The iodoarene 8 [12][16] was facilely synthesized from sesamol (6) via methylation and iodination in an overall yield of 67%. With the

Comparison of crystal structure and DFT calculations of triferrocenyl trithiophosphite’s conformance

• Ruslan P. Shekurov,
• Mikhail N. Khrizanforov,
• Ilya A. Bezkishko,
• Tatiana P. Gerasimova,
• Almaz A. Zagidullin,
• Daut R. Islamov and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1499–1504, doi:10.3762/bjoc.18.157

• of Sciences. Synthesis To a suspension of white phosphorus (0.08 g, 0.645 mmol) in acetone (30 mL) were added diferrocenyldisulfide (1.68 g, 3.8 mmol) and 0.2 mL 15 N solution of potassium hydroxide. The reaction mixture was stirred for 12 h at room temperature and then the solvent was evaporated in

Preparation of an advanced intermediate for the synthesis of leustroducsins and phoslactomycins by heterocycloaddition

• Anaïs Rousseau,
• Guillaume Vincent and
• Cyrille Kouklovsky

Beilstein J. Org. Chem. 2022, 18, 1385–1395, doi:10.3762/bjoc.18.143

• -triisopropylsilyloxyhexa-1,3-dien (17): A 0.5 M solution of potassium hexamethyldisilazide in toluene (4.4 mL, 2.22 mmol, 1.2 equiv) was added to a cooled (−78 °C) solution of diethyl chlorophosphate (0.27 mL, 1.85 mmol) in anhydrous THF (7 mL). A solution of the enone 16 (500 mg, 1.85 mmol) in THF (6 mL) was then slowly

Synthesis and electrochemical properties of 3,4,5-tris(chlorophenyl)-1,2-diphosphaferrocenes

• Almaz A. Zagidullin,
• Farida F. Akhmatkhanova,
• Mikhail N. Khrizanforov,
• Robert R. Fayzullin,
• Tatiana P. Gerasimova,
• Ilya A. Bezkishko and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1338–1345, doi:10.3762/bjoc.18.139

• ppm for 1c). Further, reaction mixtures with compounds 1 were treated with SOCl2 for 3–4 h at 0 °C and converted to chloro derivatives 2. In the next step, compounds 2 and starting substituted benzaldehydes were subsequently treated with 2 equiv of potassium tert-butoxide in THF for 18 hours at room

• distilled at reduced pressure to give pure compounds. In a final step, we used the above mentioned approach of combining the C1 and C2 building blocks and found that chloroarylcarbenes, generated from the corresponding benzal chlorides 4b,c under the action of potassium tert-butoxide, reacted with 1,2-bis

Molecular diversity of the base-promoted reaction of phenacylmalononitriles with dialkyl but-2-ynedioates

• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 991–998, doi:10.3762/bjoc.18.99

• ). Results and Discussion Initially, the reaction conditions were briefly optimized by using p-methylphenacylmalononitrile (1a) and diethyl but-2-ynedioate (2a) as standard according to the previous reported work [31]. In the presence of potassium carbonate and tetrabutylammonium chloride (TBAC), the

First example of organocatalysis by cathodic N-heterocyclic carbene generation and accumulation using a divided electrochemical flow cell

• Daniele Rocco,
• Ana A. Folgueiras-Amador,
• Richard C. D. Brown and
• Marta Feroci

Beilstein J. Org. Chem. 2022, 18, 979–990, doi:10.3762/bjoc.18.98

• by staining with potassium permanganate. Flash column chromatography was performed using high purity silica gel, pore size 60 Å, 230–400 mesh particle size, purchased from Merck. 1H NMR and 13C NMR spectra were recorded in CDCl3 (purchased from Cambridge Isotope Laboratories) at 298 K using a Bruker

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• )dithieno[3,2-b:2’,3’-d]thiophene (26): a) Br2, CHCl3, rt, overnight, reflux, 4 h, 94% [33]; b) n-BuLi, −78 °C, 30 min, 1-formylpiperidine, anhydrous THF, −78 °C, then rt, overnight [15], 88%; c) ethyl thioglycolate, anhydrous potassium carbonate, anhydrous N,N-dimethylformamide, rt, 3 d, 83% [15]; d) 1 M

On Reuben G. Jones synthesis of 2-hydroxypyrazines

• Pierre Legrand and
• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93

• (Table 2, entries 5 and 6 in comparison with entry 2). Trials using ethanol or isopropanol as a solvent (Table 2, entries 7 and 8) were not successful, plausibly because of a precipitation of the reaction medium before the end of the base addition. Trials with lithium or potassium hydroxide (Table 2

Synthesis and HDAC inhibitory activity of pyrimidine-based hydroxamic acids

• Virginija Jakubkiene,
• Gabrielius Ernis Valiulis,
• Markus Schweipert,
• Asta Zubriene,
• Daumantas Matulis,
• Franz-Josef Meyer-Almes and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 837–844, doi:10.3762/bjoc.18.84

• alkylation reaction of compound 19 with methyl 6-bromohexanoate and select the conditions favoring the formation of the O-isomer, a weak base, potassium carbonate, and a bipolar aprotic solvent, dimethylformamide, were used. The reaction was carried out at room temperature for 120 hours and a significant

Synthesis of α-(perfluoroalkylsulfonyl)propiophenones: a new set of reagents for the light-mediated perfluoroalkylation of aromatics

• Durbis J. Castillo-Pazos,
• Juan D. Lasso and
• Chao-Jun Li

Beilstein J. Org. Chem. 2022, 18, 788–795, doi:10.3762/bjoc.18.79

• 2-(perfluorohexyl)-1,1-diphenylethylene (8), and propiophenone through GC–MS analysis. Additionally, the presence of free SO2 gas was confirmed by the reaction of acidic potassium dichromate solution on paper (green coloration of the exposed surface). See Supporting Information File 1 for details

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• (34, obtained from castor oil) and benzaldehyde (33). In the industrial process, stoichiometric amounts of sodium- or potassium hydroxide are used resulting in the formation of large quantities of undesired side products, e.g., enone 36, the aldol condensation product of two molecules of heptanal [9

• ) following the Perkin synthesis (Scheme 10) [42]. Salicylaldehyde (44) is mixed with a solution of potassium acetate and acetic acid in acetic anhydride. The reaction mixture is pumped through two separated tube reactors at 150 °C and 240 °C, respectively, proceeding with a combined residence time of 22.5

• = mass flow controller. Synthesis of thymol (41) from m-cresol (39) and isopropyl alcohol via Fries-type rearrangement of ether 40. Preparation of coumarin (46) by reaction of salicylaldehyde (44) with potassium acetate, acetic acid, and acetic anhydride at elevated temperature in two separated tube

A trustworthy mechanochemical route to isocyanides

• Francesco Basoccu,
• Federico Cuccu,
• Federico Casti,
• Rita Mocci,
• Claudia Fattuoni and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 732–737, doi:10.3762/bjoc.18.73

• straightforward procedure. Keywords: green chemistry; isocyanide; isonitriles; mechanochemistry; Introduction Isocyanides were first discovered more than a century ago by Lieke in Göttingen after having handled allyl iodide and potassium cyanide to synthesize crotonic acid. This attempt, instead, brought to the

• organic bases like potassium tert-butoxide and imidazole proved to be as effective as triethylamine. Much to our surprise, we observed that the association between only 1 equivalent of triethylamine and 6 equivalents of sodium carbonate brought a good conversion rate of 1f in 2f at a frequency of 36 Hz

Shift of the reaction equilibrium at high pressure in the continuous synthesis of neuraminic acid

• Jannis A. Reich,
• Miriam Aßmann,
• Kristin Hölting,
• Paul Bubenheim,
• Jürgen Kuballa and
• Andreas Liese

Beilstein J. Org. Chem. 2022, 18, 567–579, doi:10.3762/bjoc.18.59

• . Chemicals All compounds were ordered from Biosynth Carbosynth (United Kingdom) and used without further purification. Buffer preparation: potassium phosphate buffer: 5.3 mL of 0.2 M potassium dihydrogenphosphate (KH2PO4) with 94.7 mL of 0.2 M potassium hydrogenphosphate (K2HPO4) in 100 mL water resulting in

• 200 mL of 100 mM solution. The pH was measured and afterwards adjusted to pH 7.50 or 8.00 by adding more potassium dihydrogen- or monohydrogenphophate solution. 1 M Tris buffer: 121.14 g tris(hydroxymethyl)aminomethane was dissolved in 800 mL H2O, the volume was filled up to 1 L with H2O, and the pH

• regression, the error given corresponds to the 95% confidence interval. All particles were pestled to remove potential diffusion limitations. All experiments were conducted at 40 °C and in potassium phosphate buffer. Since the pump is intended for UHPLC applications, a mixing chamber was installed for up to

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• useful alkylation approach is the Kochi–Anderson method [76] (or also known as Jacobsen–Torssell method [77][78]), via oxidative decarboxylation, where the quinone reacts with a carboxylic acid in the presence of silver(I) nitrate and ammonium or potassium peroxydisulfate. Nucleophilic free radicals are

• in Scheme 17 below the optimized reaction conditions are shown for the synthesis of compounds 62 and 64 (Scheme 17) [110]. In 2019, Sultan and co-workers described a methodology for the synthesis of quinone derivatives using a combination of potassium persulfate, trifluoroacetic acid (TFA), and blue

• method [77]) where 10 reacts with a carboxylic acid in the presence of silver(I) nitrate and ammonium or potassium peroxydisulfate (Scheme 29). In the past twenty years, several menadione alkylation studies have been carried out based on the Kochi–Anderson method [131][132][133][134][135][136][137][138

Borylated norbornadiene derivatives: Synthesis and application in Pd-catalyzed Suzuki–Miyaura coupling reactions

• Robin Schulte and
• Heiko Ihmels

Beilstein J. Org. Chem. 2022, 18, 368–373, doi:10.3762/bjoc.18.41

• of the resulting metalated norbornadiene with bis(pinacolato)diborone gave the 4,4,5,5-tetramethyl-2-(bicyclo[2.2.1]heptadien-2-yl)-1,3,2-dioxaborolane (2a) in 69% yield (Scheme 1). Subsequent treatment of product 2a with aqueous KHF2 solution resulted in the formation of potassium bicyclo[2.2.1

Regioselectivity of the S_EAr-based cyclizations and S_EAr-terminated annulations of 3,5-unsubstituted, 4-substituted indoles

• Jonali Das and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2022, 18, 293–302, doi:10.3762/bjoc.18.33

• and co-workers reported that the ring closure of the Pictet−Spengler reaction between 2-(1H-indol-4-yl)ethanamine (10) and secologanin (11) in potassium phosphate buffer (KPi) at 70 °C regioselectively took place at the indole C3 position, resulting in unstable 4β-(R)-1H-azepino[3,4,5-cd

Iridium-catalyzed hydroacylation reactions of C1-substituted oxabenzonorbornadienes with salicylaldehyde: an experimental and computational study

• Angel Ho,
• Austin Pounder,
• Krish Valluru,
• Leanne D. Chen and
• William Tam

Beilstein J. Org. Chem. 2022, 18, 251–261, doi:10.3762/bjoc.18.30

• reaction with C1-substituted methyl OBD (MeOBD) with salicylaldehyde catalyzed by [Ir(COD)OH]2 was chosen as the model reaction. As the reaction is in the presence of 5 M KOH, the potassium salt of salicylaldehyde was used rather than the protonated species for all calculations. Likewise, [Ir(COD)OH]2, and

Ready access to 7,8-dihydroindolo[2,3-d][1]benzazepine-6(5H)-one scaffold and analogues via early-stage Fischer ring-closure reaction

• Irina Kuznetcova,
• Felix Bacher,
• Daniel Vegh,
• Hsiang-Yu Chuang and
• Vladimir B. Arion

Beilstein J. Org. Chem. 2022, 18, 143–151, doi:10.3762/bjoc.18.15

• further reacted with potassium cyanide to yield nitrile 12 [27]. Saponification of the nitrile was performed by exploiting the Pinner reaction with saturated HCl gas in methanol. This led to methyl indol-2-ylacetate (13) in 83% yield [28]. The hydrolysis of ester 13 was performed in the presence of

Mechanistic studies of the solvolysis of alkanesulfonyl and arenesulfonyl halides

• Malcolm J. D’Souza and
• Dennis N. Kevill

Beilstein J. Org. Chem. 2022, 18, 120–132, doi:10.3762/bjoc.18.13

• with an SN2 pathway. Introduction of methyl groups onto the aromatic ring considerably reduced the selectivity ratio, with specific rate values [14] of 1.66 × 10−4 s−1 in 100% H2O increasing only to 1.73 × 10−4 s−1 in the presence of 0.004 M potassium hydroxide. The only small difference between the

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• Pd source together with the water-soluble Buchwald ligand sulfonated SPhos (sSPhos) and potassium fluoride as a base. The reaction was performed in a solvent mixture of dimethoxyethane, ethanol and water (DME/EtOH/H2O 9:9:2) at 120 °C under microwave irradiation for 30 min (Scheme 1) [78]. The

DABCO-promoted photocatalytic C–H functionalization of aldehydes

• Bruno Maia da Silva Santos,
• Mariana dos Santos Dupim,
• Cauê Paula de Souza,
• Thiago Messias Cardozo and
• Fernanda Gadini Finelli

Beilstein J. Org. Chem. 2021, 17, 2959–2967, doi:10.3762/bjoc.17.205

• and co-workers demonstrated the generation of highly reductant CO2 radical anions through potassium formate hydrogen atom abstraction promoted by DABCO [25] (Figure 2c). This species was then used for reduction of (hetero)aryl and alkyl halides, and subsequent carboarylation of several styrenes

• -bromobenzonitrile (2) under different amounts of DABCO. Two inorganic bases were tested: potassium carbonate (K2CO3) and sodium hydrogen carbonate (NaHCO3). Reactions in the absence of inorganic bases were also performed (Table 1). An excited iridium photocatalyst (Ir[dF(CF3)ppy]2(dtbbpy)PF6) was used for the one

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

• Nicolai Wippert,
• Martin Nieger,
• Claudine Herlan,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2021, 17, 2773–2780, doi:10.3762/bjoc.17.187

• . Diisopropylamine and an aqueous solution of potassium carbonate were added to the in-situ generated diazonium salt according to literature-known protocols [40]. The resulting 3-(3,3-diisopropyltriaz-1-en-1-yl)-1H-pyrazole-4-carbonitrile (15) was used as starting material for the attempts to add different side

• chains to the pyrazole moiety. The addition of several aliphatic bromides or iodides 14 in combination with potassium or cesium carbonate in DMSO gave a mixture of the regioisomeric compounds 12 and 13 due to the addition of the alkyl substituents to one of both pyrazole-nitrogen atoms. As shown in Table