One-pot synthesis of dicyclopenta-fused peropyrene via a fourfold alkyne annulation

• Ji Ma,
• Yubin Fu,
• Junzhi Liu and
• Xinliang Feng

Beilstein J. Org. Chem. 2020, 16, 791–797, doi:10.3762/bjoc.16.72

• solvents, such as dichloromethane, chloroform, tetrahydrofuran and toluene, allowing a full characterization by NMR analyses. Finally, the palladium-catalyzed cyclopentannulation of compound 5 with 1,2-diphenylethyne under microwave conditions using the catalyst system of [Pd2(dba)3] and P(o-tol)3 afforded

Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules

• Valerian Dragutan,
• Ileana Dragutan,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68

• stereoselective formation of the tetrahydrofuran rings. Conclusion This review highlighted the most recent efforts regarding the development of enyne metathesis-based syntheses of complex bioactive, natural and nonnatural organic molecules. Both, intra- and intermolecular enyne metatheses have been valorized to

Rhodium-catalyzed reductive carbonylation of aryl iodides to arylaldehydes with syngas

• Zhenghui Liu,
• Peng Wang,
• Zhenzhong Yan,
• Suqing Chen,
• Dongkun Yu,
• Xinhui Zhao and
• Tiancheng Mu

Beilstein J. Org. Chem. 2020, 16, 645–656, doi:10.3762/bjoc.16.61

• (PMP)), and solvents (N,N-dimethylacetamide (DMA), 1,3-dimethyl-2-imidazolidinone (DMI), N-methyl-2-pyrrolidinone (NMP), tetrahydrofuran (THF), 1,4-dioxane, ethanol, methanol, acetonitrile, and toluene) together with aryl iodides and other reagents were purchased from commercial sources (namely J&K

Design and synthesis of diazine-based panobinostat analogues for HDAC8 inhibition

• Sivaraman Balasubramaniam,
• Sajith Vijayan,
• Liam V. Goldman,
• Xavier A. May,
• Kyra Dodson,
• Sweta Adhikari,
• Fatima Rivas,
• Davita L. Watkins and
• Shana V. Stoddard

Beilstein J. Org. Chem. 2020, 16, 628–637, doi:10.3762/bjoc.16.59

• designed analogues and evaluating their overall potential to inhibit neuroblastoma cell growth. Experimental General Reagents and solvents were purchased from commercial sources and used without further purification unless otherwise specified. Tetrahydrofuran (THF), ether, dichloromethane (DCM), and

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

• reacted with 4-aminomethylpiperidine (AMP, 21) or piperazine (PIP) to afford G1-AAA–SBA-15 (G1-AMP–SBA-15, 22, or G2-PIP–SBA-15, 23) materials (Scheme 3). The resulting solid product was then filtrated and washed with methanol, dichloromethane, and tetrahydrofuran. The organic part of the G1-AAA–SBA-15

Aerobic synthesis of N-sulfonylamidines mediated by N-heterocyclic carbene copper(I) catalysts

• Faïma Lazreg,
• Marie Vasseur,
• Alexandra M. Z. Slawin and
• Catherine S. J. Cazin

Beilstein J. Org. Chem. 2020, 16, 482–491, doi:10.3762/bjoc.16.43

• (see Supporting Information File 1 for details). Tetrahydrofuran (THF), 1,2-DCE, 1,4-dioxane and acetonitrile proved to be the most suitable solvents for this transformation (Table 1). Interestingly, similar results were obtained for complexes 1–5, while 6 displayed superior activity. Indeed, 71

Architecture and synthesis of P,N-heterocyclic phosphine ligands

• Wisdom A. Munzeiwa,
• Bernard Omondi and
• Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

• ]. Thus, the diphosphine ligand 51 was obtained in good yield by reacting 2,6-bis(chloromethyl)pyridine (50) with phosphine lithiothiolate 49. The latter was obtained by treatment of diphenylphosphine (48) with n-BuLi and ethylene sulfide in tetrahydrofuran at very low temperatures. Metal–proton exchange

• protocol with free amine spiro-amino alcohol derivative 124 gave compounds 125 and 127 (R = H) in low yields. An optimized procedure was used where dichlorophenylphosphine and borane·dimethyl sulfide in tetrahydrofuran were premixed at −78 °C. The temperature was then raised to 25 °C before neutralizing

p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

• Panagiotis S. Gritzapis,
• Panayiotis C. Varras,
• Nikolaos-Panagiotis Andreou,
• Katerina R. Katsani,
• Konstantinos Dafnopoulos,
• George Psomas,
• Zisis V. Peitsinis,
• Alexandros E. Koumbis and
• Konstantina C. Fylaktakidou

Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33

• + 12 + CR (200 μM) + UV. Synthesis of O-carbamoyl amidoximes (8–13), ethanone oximes (15–20) and aldoximes (22–27). Oxime 1 or 14 or 21, Et3N (1.1 equiv), R–NCO (1.1–1.8 equiv), dry chloroform or tetrahydrofuran, Ar, 0 °C → rt or reflux, 19–97%. Photodissociation reaction of the derivative 12 in the T1

Halogen-bonding-induced diverse aggregation of 4,5-diiodo-1,2,3-triazolium salts with different anions

• Xingyu Xu,
• Shiqing Huang,
• Zengyu Zhang,
• Lei Cao and
• Xiaoyu Yan

Beilstein J. Org. Chem. 2020, 16, 78–87, doi:10.3762/bjoc.16.10

• good yield (Scheme 1). The product 2-I was characterized by 1H NMR, 13C NMR, and high-resolution mass spectrometry. 2-I has a poor solubility in most organic solvents such as dichloromethane, trichloromethane, tetrahydrofuran, and ethanol. A single crystal of 2-I was obtained by slow diffusion of ether

Photoreversible stretching of a BAPTA chelator marshalling Ca²⁺-binding in aqueous media

• Aurélien Ducrot,
• Arnaud Tron,
• Robin Bofinger,
• Ingrid Sanz Beguer,
• Jean-Luc Pozzo and
• Nathan D. McClenaghan

Beilstein J. Org. Chem. 2019, 15, 2801–2811, doi:10.3762/bjoc.15.273

• MHz) or an Avance 300 (1H: 300 MHz, 13C: 75 MHz) spectrometer. Chemical shifts are reported in ppm (δ) and are referenced to the NMR solvent residual peaks. Abbreviations used are s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet. Reagent grade tetrahydrofuran (THF) was distilled under

An improved, scalable synthesis of Notum inhibitor LP-922056 using 1-chloro-1,2-benziodoxol-3-one as a superior electrophilic chlorinating agent

• Nicky J. Willis,
• Elliott D. Bayle,
• George Papageorgiou,
• David Steadman,
• Benjamin N. Atkinson,
• William Mahy and
• Paul V. Fish

Beilstein J. Org. Chem. 2019, 15, 2790–2797, doi:10.3762/bjoc.15.271

• . Yields are the ranges obtained from repeated reactions. DMF, N,N-dimethylformamide; NBS, N-bromosuccinimide; THF, tetrahydrofuran. Chlorination of 6 with N-chlorosuccinimide (NCS). Reagents and conditions: (a) NCS (1.2 equiv), AcOH, 55 °C, 7 h, 15–32%. Improved synthesis of 5. Reagents and conditions: (a

Arylisoquinoline-derived organoboron dyes with a triaryl skeleton show dual fluorescence

• Vânia F. Pais,
• Tristan Neumann,
• Ignacio Vayá,
• M. Consuelo Jiménez,
• Abel Ros and
• Uwe Pischel

Beilstein J. Org. Chem. 2019, 15, 2612–2622, doi:10.3762/bjoc.15.254

• emission band with a maximum at 401, 442, and 420 nm, in acetonitrile, respectively. These are tentatively assigned to π–π* transitions of the variable aryl moiety. Interestingly, in tetrahydrofuran, containing oxygen as donor atom, only the SW emission band is seen, i.e., λfluo,max = 409 nm (16), 402 nm

• LW band is substituted by a strong blue-shifted emission. This leads to a clear ratiometric behavior and a large dynamic response. The blue-shifted emission for the fluoroboronate Lewis adduct is in accordance with the observations made for donor solvents such as tetrahydrofuran (see above). As for

Synthetic terpenoids in the world of fragrances: Iso E Super^® is the showcase

• Alexey Stepanyuk and
• Andreas Kirschning

Beilstein J. Org. Chem. 2019, 15, 2590–2602, doi:10.3762/bjoc.15.252

• yield a new cation, which in turn is nucleophilically trapped by the carbinol moiety. The resulting tetrahydrofuran 59 is chemically stable and this observation was used as rationale for the erosion of the isomeric ratio observed during prolonged reaction times. In the same piece of work Fráter et al

• Plus® (34). Products 58 (α double bond) and product 53 (β double bond) are not desired [26]. Iso E Super Plus® (34) can undergo a third cyclisation to tetrahydrofuran 59 through compound rac-53 [22]. New unnatural terpenoid 70 from unnatural farnesyl pyrophosphate derivative 69 and comparison with

• natural biotransformation (67→68) and olfactory property of tetrahydrofuran 70 [39]. Individual components of the complex Iso E Super® mixture. Top fragrances with regard to their volume percentage (listed down to about 20%; the large number of perfumes with lower percentages are not listed) of Iso E

α,ß-Didehydrosuberoylanilide hydroxamic acid (DDSAHA) as precursor and possible analogue of the anticancer drug SAHA

• Shital K. Chattopadhyay,
• Subhankar Ghosh,
• Sarita Sarkar and
• Kakali Bhadra

Beilstein J. Org. Chem. 2019, 15, 2524–2533, doi:10.3762/bjoc.15.245

• , removal of the O-benzyl group keeping the double bond intact proved to be problematic under a range of conditions. Pleasingly, use of BCl3 in tetrahydrofuran solvent effected the desired transformation but in a modest yield of 51%. Changing the solvent to dichloromethane and using a lower temperature

Sugar-derived oxazolone pseudotetrapeptide as γ-turn inducer and anion-selective transporter

• Sachin S. Burade,
• Sushil V. Pawar,
• Tanmoy Saha,
• Navanath Kumbhar,
• Amol S. Kotmale,
• Manzoor Ahmad,
• Pinaki Talukdar and
• Dilip D. Dhavale

Beilstein J. Org. Chem. 2019, 15, 2419–2427, doi:10.3762/bjoc.15.234

• stereochemically stable quaternary carbon center [1]. For example, TAA-derived peptides containing a cyclopropane ring and ʟ/ᴅ-dimethyl tartrate showed an α-turn and form 310-helical conformations in higher oligomers [2][3][4]. While, TAA-derived peptides having a tetrahydrofuran ring demonstrated a β-turn type

Effect of ring size on photoisomerization properties of stiff stilbene macrocycles

• Sandra Olsson,
• Óscar Benito Pérez,
• Magnus Blom and
• Adolf Gogoll

Beilstein J. Org. Chem. 2019, 15, 2408–2418, doi:10.3762/bjoc.15.233

• dichloromethane (DCM), ethyl acetate, pentane, tetrahydrofuran (THF) and toluene that were distilled before use. N,N-Dimethylformamide (DMF) was used as supplied (biotech. grade, ≥99.9%). Unless stated differently, all reactions were carried out under atmospheric pressure and with argon atmosphere. Microwave (MW

Synthesis of acremines A, B and F and studies on the bisacremines

• Nils Winter and
• Dirk Trauner

Beilstein J. Org. Chem. 2019, 15, 2271–2276, doi:10.3762/bjoc.15.219

• should then close the tetrahydrofuran ring of the natural product. Upon irradiation of 5 using a Hg lamp, however, the only productive pathway which could be observed was isomerization of the disubstituted double bond (Table 1, entries 17 and 18). Again, we attempted to promote the reaction by tethering

Multiple threading of a triple-calix[6]arene host

• Veronica Iuliano,
• Roberta Ciao,
• Emanuele Vignola,
• Carmen Talotta,
• Patrizia Iannece,
• Margherita De Rosa,
• Annunziata Soriente,
• Carmine Gaeta and
• Placido Neri

Beilstein J. Org. Chem. 2019, 15, 2092–2104, doi:10.3762/bjoc.15.207

• mass spectra were calibrated externally, and a linear calibration was applied. All chemicals were reagent grade and were used without further purification. Tetrahydrofuran was dried by heating under reflux over sodium wire in the presence of benzophenone as indicator while dimethylformamide was dried

Archangelolide: A sesquiterpene lactone with immunobiological potential from Laserpitium archangelica

• Silvie Rimpelová,
• Michal Jurášek,
• Lucie Peterková,
• Jiří Bejček,
• Vojtěch Spiwok,
• Miloš Majdl,
• Michal Jirásko,
• Miloš Buděšínský,
• Juraj Harmatha,
• Eva Kmoníčková,
• Pavel Drašar and
• Tomáš Ruml

Beilstein J. Org. Chem. 2019, 15, 1933–1944, doi:10.3762/bjoc.15.189

• , dicyclohexylurea; Dns, dansyl amide; DMAP, 4-dimethylaminopyridine; DTB, 8-O-(dodecanoyl-8-O-debutanoyltrilobolid); IL-6, interleukin 6; IL-1β, interleukin 1β; INF-γ, interferon gamma; TBTA, tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine; TEA, triethylamine; THF, tetrahydrofuran; TLC, thin-layer chromatography

Complexation of 2,6-helic[6]arene and its derivatives with 1,1′-dimethyl-4,4′-bipyridinium salts and protonated 4,4'-bipyridinium salts: an acid–base controllable complexation

• Jing Li,
• Qiang Shi,
• Ying Han and
• Chuan-Feng Chen

Beilstein J. Org. Chem. 2019, 15, 1795–1804, doi:10.3762/bjoc.15.173

• methyl-substituted derivative H2 were prepared according to previously reported methods [30]. Starting from helic[6]arene H1, helic[6]arene derivatives H3 and H4 were conveniently synthesized by etherification of H1 with bromobutane or 2-bromoethyl methyl ether, respectively, in tetrahydrofuran in the

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

• Iwona E. Głowacka,
• Aleksandra Trocha,
• Andrzej E. Wróblewski and
• Dorota G. Piotrowska

Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168

• both pairs of ethyl esters [26]. When a mixture of tert-butyl esters (2R,1'S)-5d and (2S,1'S)-5d was subjected to kinetic resolution in the presence of potassium tert-butoxide in tetrahydrofuran (2R,1'S)-5d was produced with low 40% de [27]. The absolute configuration at C2 in esters 5 was established

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Synthesis, enantioseparation and photophysical properties of planar-chiral pillar[5]arene derivatives bearing fluorophore fragments

• Guojuan Li,
• Chunying Fan,
• Guo Cheng,
• Wanhua Wu and
• Cheng Yang

Beilstein J. Org. Chem. 2019, 15, 1601–1611, doi:10.3762/bjoc.15.164

• toluene (40 mL), tetrahydrofuran (60 mL) and water (10 mL). After bubbling argon through the mixture for 15 min, Pd(PPh3)4 (300 mg, 0.3 mmol) was added, and the mixture was stirred and refluxed for 8 h. Then, the reaction mixture was extracted with dichloromethane, and the organic layer was dried over

Transient and intermediate carbocations in ruthenium tetroxide oxidation of saturated rings

• Manuel Pedrón,
• Laura Legnani,
• Maria-Assunta Chiacchio,
• Pierluigi Caramella,
• Tomás Tejero and
• Pedro Merino

Beilstein J. Org. Chem. 2019, 15, 1552–1562, doi:10.3762/bjoc.15.158

• tetroxide-mediated oxidation of cyclopentane, tetrahydrofuran, tetrahydrothiophene and N-substituted pyrrolidines has been studied computationally by DFT and topological (analysis of the electron localization function, ELF) methods. In agreement with experimental observations and previous DFT calculations

• oxidation of cyclopentane, tetrahydrofuran, tetrahydrothiophene, and N-methyl- and N-benzylpyrrolidine to evaluate the extension in which transient carbocations can be formed (and whether they can become energy minima) during the rate-limiting step (Scheme 3). The RuO4 oxidation of cyclopentane [44] and

• tetrahydrofuran [45] have been experimentally reported as well as the oxidation of N-acylpyrrolidines to the corresponding lactams [46]. Admittedly, the oxidation of tetrahydrothiophene has been approached only computationally since in that case the sulfur atom would be more easily oxidized. Since the general

A novel three-component reaction between isocyanides, alcohols or thiols and elemental sulfur: a mild, catalyst-free approach towards O-thiocarbamates and dithiocarbamates

• András György Németh,
• György Miklós Keserű and
• Péter Ábrányi-Balogh

Beilstein J. Org. Chem. 2019, 15, 1523–1533, doi:10.3762/bjoc.15.155

• and HPLC–MS. Based on preliminary experiments in our laboratory, the reaction was performed in tetrahydrofuran (THF) at 40 °C for 1 h using a 1.5 equiv excess of sodium hydride as the base, S8 and the alcohol component (Table 1, entry 1) resulting in the desired thiocarbamate 3a in 58% yield. During