Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• ). The active catalytic species for the CuAAC reaction were generated by reducing copper(II) sulfate with sodium ascorbate according to literature procedures [66][67]. 2-Azido-1,3,5-trimethylbenzene (mesityl azide) was easily synthesized in a distinct, preliminary step through the Sandmeyer reaction of

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

• benzyl azide 3 in situ from benzyl bromide (5) and sodium azide and to directly trap the intermediate with alkyne 2. Under conditions summarized in reaction 3 of Scheme 2 we obtained the desired 1,2,3-triazole derivative 3 in 82% yield. Copper(II) sulfate pentahydrate (0.07 equivalents based on 2) in the

• allowed to lower the reaction temperature from 60 °C to 40 °C, but it also induced full consumption of the intermediate biazide derived from dihalide 11 (Scheme 4, reaction 3); 0.2 equiv of copper(II) sulfate pentahydrate, 0.4 equiv of sodium ascorbate and 0.4 equiv of ʟ-proline in very little of

Radical ligand transfer: a general strategy for radical functionalization

• David T. Nemoto Jr,
• Kang-Jie Bian,
• Shih-Chieh Kao and
• Julian G. West

Beilstein J. Org. Chem. 2023, 19, 1225–1233, doi:10.3762/bjoc.19.90

• elimination-like pathway to afford unsaturated C–C bonds in the presence of copper(II) sulfate, presumably via competitive RPC to the carbocation followed by E1 olefination. Kochi also demonstrated that RLT can be combined with other radical generation strategies to enable new, non-biomimetic reactions to be

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

• Man-Ping Li,
• Nan Yang and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2022, 18, 539–548, doi:10.3762/bjoc.18.56

• 90% acetonitrile with 0.1% formic acid and 10% water with 0.1% formic acid at a flow rate of 0.4 mL/min. Freeze-drying was conducted on a Scientz-18N freeze-dryer. Synthesis of compound 2. A mixture of compound 1 (2.30 g, 3.7 mmol), ethyl azidoacetate (5.76 g, 44.7 mmol), copper(II) sulfate

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• -2,3,4,6-tetraacetylglucose (1.48 g, 3.96 mmol), copper(II) sulfate pentahydrate (52 mg, 0.21 mmol), and sodium ascorbate (28 mg, 0.14 mmol) in tetrahydrofuran/water cosolvent 2:1 (10 mL, v/v) was stirred vigorously under nitrogen in the dark at 60 °C for 24 h. Then, the solvent was removed under reduced

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

• synthesized by adding a methanolic solution of copper(II) sulfate to 124, and this was allowed to stir for 2 h. The resulting nanoparticles were collected from the solution by centrifugation and washed/sonicated with methanol. Finally, 125 was dried before use in the reactions (Scheme 27). Pectin (122) is a

Homo- and hetero-difunctionalized β-cyclodextrins: Short direct synthesis in gram scale and analysis of regiochemistry

• Gábor Benkovics,
• Mihály Bálint,
• Éva Fenyvesi,
• Erzsébet Varga,
• Szabolcs Béni,
• Konstantina Yannakopoulou and
• Milo Malanga

Beilstein J. Org. Chem. 2019, 15, 710–720, doi:10.3762/bjoc.15.66

• presence of copper(II) sulfate (reactions 4 and 5, respectively, Scheme 3). The product formation in both cases was ascertained by direct-phase TLC, 1H NMR and reversed-phase HPLC. The monoazido-monotosylated fraction was isolated using reversed-phase PCC with water/methanol gradient elution in 35% yield

Nucleoside macrocycles formed by intramolecular click reaction: efficient cyclization of pyrimidine nucleosides decorated with 5'-azido residues and 5-octadiynyl side chains

• Jiang Liu,
• Peter Leonard,
• Sebastian L. Müller,
• Constantin Daniliuc and
• Frank Seela

Beilstein J. Org. Chem. 2018, 14, 2404–2410, doi:10.3762/bjoc.14.217

• ” reaction leading to a macrocycle or (ii) an intermolecular “click” reaction forming dimeric or oligomeric compounds. For a deeper insight, the “click” reaction was executed under different reaction conditions. First, the copper(I)-promoted “click” reaction was performed on 2 in the presence of copper(II

• ) sulfate and ascorbic acid. TLC monitoring showed that the cyclization failed. Then, tris(benzyltriazoylmethyl)amine (TBTA) [40][41][42] was added as catalyst and macrocycle 4 was formed in 71% yield, which is extremely high for an intramolecular cyclization. The dimeric product 3 and the cyclic dimer 5

Synthesis of spirocyclic scaffolds using hypervalent iodine reagents

• Fateh V. Singh,
• Priyanka B. Kole,
• Saeesh R. Mangaonkar and
• Samata E. Shetgaonkar

Beilstein J. Org. Chem. 2018, 14, 1778–1805, doi:10.3762/bjoc.14.152

• synthesis of spiro β-lactams via oxidative dearomatization reactions. In this report, the synthesis of spiro β-lactams 56 were achieved successfully by the oxidative cyclization of p-substituted phenols 55 using PIDA (15) as an electrophile and copper(II) sulfate pentahydrate as an additive in the presence

Versatile synthesis of end-reactive polyrotaxanes applicable to fabrication of supramolecular biomaterials

• Atsushi Tamura,
• Asato Tonegawa,
• Yoshinori Arisaka and
• Nobuhiko Yui

Beilstein J. Org. Chem. 2016, 12, 2883–2892, doi:10.3762/bjoc.12.287

• )ethylamine (HEEA) were obtained from TCI (Tokyo, Japan). 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) and copper(II) sulfate pentahydrate (CuSO4) were obtained from Wako Pure Chemical Industries (Osaka, Japan). N,N’-Carbonyldiimidazole (CDI) and (+)-sodium L-ascorbate were

Design, synthesis and photochemical properties of the first examples of iminosugar clusters based on fluorescent cores

• Mathieu L. Lepage,
• Antoine Mirloup,
• Manon Ripoll,
• Fabien Stauffert,
• Anne Bodlenner,
• Raymond Ziessel and
• Philippe Compain

Beilstein J. Org. Chem. 2015, 11, 659–667, doi:10.3762/bjoc.11.74

• bearing a tetraethylene glycol chain tethered to the boron center via an ethynyl bond proved difficult. The use of copper(I) bromide dimethyl sulfide complex [63] at room temperature led to a complex mixture of products. Better results were obtained with copper(II) sulfate and sodium ascorbate under

Host–guest-driven color change in water: influence of cyclodextrin on the structure of a copper complex of poly((4-hydroxy-3-(pyridin-3-yldiazenyl)phenethyl)methacrylamide-co-dimethylacrylamide)

• Nils Retzmann,
• Gero Maatz and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 2480–2483, doi:10.3762/bjoc.10.259

• experiments. Keywords: cyclodextrin; copolymer; copper(II) sulfate; supramolecular; water complex; Introduction In recent years, the interest in stimuli-responsive polymers increased exponentially [1]. Many polymers have been described, showing sensitivity towards e.g. light, pH and heat [2][3][4

• :50 vol % in methanol/water solution. UV–vis absorption spectra of (orange) the solved copolymer 7 with the induced shifts by addition of (red) copper(II) sulfate and (blue) γ-CD in an aqueous methanol medium. Number average particle size distribution of 7 obtained by DLS experiments. Synthesis of N

A small azide-modified thiazole-based reporter molecule for fluorescence and mass spectrometric detection

• Stefanie Wolfram,
• Hendryk Würfel,
• Stefanie H. Habenicht,
• Christine Lembke,
• Phillipp Richter,
• Eckhard Birckner,
• Rainer Beckert and
• Georg Pohnert

Beilstein J. Org. Chem. 2014, 10, 2470–2479, doi:10.3762/bjoc.10.258

• mM) of BPT (1) or the other reporter molecules (5 mM stock in DMSO), 9 µL (0.1 mM) TBTA solution (1.7 mM stock in DMSO/tert-butanol, 1:4, v/v) and 3 µL (20 mM) freshly prepared ascorbic acid solution (1.00 M in water). Samples were vortexed and 1 µL (1 mM) copper(II) sulfate solution (from a 50 mM

• (1.7 mM stock in DMSO/tert-butanol, 1:4, v/v) and 1 µL (20 mM) of a freshly prepared ascorbic acid solution (1.00 M in water). Samples were vortexed and 1 µL (1 mM) copper(II) sulfate solution (50 mM in water) was added. Samples were vortexed again and stored on ice for 1 hour. SDS-PAGE and in-gel

Multicomponent reactions in nucleoside chemistry

• Mariola Koszytkowska-Stawińska and
• Włodzimierz Buchowicz

Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179

• clay or silica gel), the use of the CeCl3/NaI catalyst system for the synthesis of intermediates 113 provided the best results in terms of reaction yield and time. The next step leading to final products 114, i.e., the reductive dehydrazination of compounds 113 with alumina-supported copper(II) sulfate

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

• solution of ND-PG-N3 (10 mg) in water (2.0 mL). Copper(II) sulfate pentahydrate (8.0 mg) in water (0.5 mL) and sodium ascorbate (10 mg) in water (0.5 mL) were added into the mixture with vigorous stirring. The resulting brown suspension was bath-sonicated for 10 min and then stirred at room temperature for

• ) NaN3, 90 °C, overnight; iv) copper(II) sulfate pentahydrate, sodium ascorbate, rt, 96 h. Hydrodynamic diameter and zeta potential of nanoparticles in Milli-Q water. Acknowledgements This work was financially supported by the Science and Technology Incubation Program in Advanced Region (JST

Advancements in the mechanistic understanding of the copper-catalyzed azide–alkyne cycloaddition

• Regina Berg and
• Bernd F. Straub

Beilstein J. Org. Chem. 2013, 9, 2715–2750, doi:10.3762/bjoc.9.308

• solution-phase conditions (Scheme 2) [12]. In their standard procedure, the cost-efficient salt copper(II) sulfate pentahydrate is reduced in situ by ascorbic acid or sodium ascorbate in a solvent mixture of water and alcohol (“Sharpless–Fokin conditions”). Alternatively, copper(I) salts such as copper(I

• ) than with the standard catalyst systems, i.e. copper(II) salts plus reducing agent or copper(I) salts [14]. This method can be significantly sped up by applying microwave radiation [43]. It is also beneficial to add copper(II) sulfate, but this is usually not mandatory as the patina on the copper

• of copper. CuAAC catalysis with mixtures of copper(II) salts and additives The most common source of copper for the CuAAC reaction are copper(II) salts. In the standard procedures introduced by Sharpless and Fokin [12], copper(II) sulfate pentahydrate is reduced in situ by sodium ascorbate, which is

Recent advances in transition metal-catalyzed Csp²-monofluoro-, difluoro-, perfluoromethylation and trifluoromethylthiolation

• Grégory Landelle,
• Armen Panossian,
• Sergiy Pazenok,
• Jean-Pierre Vors and
• Frédéric R. Leroux

Beilstein J. Org. Chem. 2013, 9, 2476–2536, doi:10.3762/bjoc.9.287

• reagent was also used recently by P. S. Baran et al. for the generation of the CF3• radical and trifluoromethylation of heteroaromatic compounds [89]. Although copper(II) sulfate (10 mol %) led to improved yields, trifluoromethylation was found to proceed in the absence of added metallic catalysts, and it

• stable and inexpensive electrophilic trifluoromethyl radical source to access trifluoromethyl-substituted alkenes [62]. Cinnamic acids were reacted with sodium trifluoromethanesulfinate and a catalytic amount of copper(II) sulfate in the presence of tert-butyl hydroperoxide (TBHP) as the radical

Superstructures of fluorescent cyclodextrin via click-reaction

• Arkadius Maciollek,
• Helmut Ritter and
• Rainer Beckert

Beilstein J. Org. Chem. 2013, 9, 827–831, doi:10.3762/bjoc.9.94

• µmol) sodium ascorbate and 18 mg (73.5 µmol) copper(II) sulfate pentahydrate were suspended in 5 mL dimethylformamide in a pressure-resistant microwave test tube provided with a magnetic stirring bar. The tube was sealed and placed in the microwave and irradiated at 140 °C and 100 W for 30 min. The

Intramolecular carbolithiation of N-allyl-ynamides: an efficient entry to 1,4-dihydropyridines and pyridines – application to a formal synthesis of sarizotan

• Wafa Gati,
• Mohamed M. Rammah,
• Mohamed B. Rammah and
• Gwilherm Evano

Beilstein J. Org. Chem. 2012, 8, 2214–2222, doi:10.3762/bjoc.8.250

• nucleophiles. By using a slightly modified Hsung’s procedure, a series of N-allyl-ynamides 1 could be readily prepared in acceptable yields using a combination of copper(II) sulfate pentahydrate (40 mol %) and 1,10-phenanthroline (80 mol %) with potassium phosphate in refluxing toluene, the major side reaction

Parallel solid-phase synthesis of diaryltriazoles

• Matthias Wrobel,
• Jeffrey Aubé and
• Burkhard König

Beilstein J. Org. Chem. 2012, 8, 1027–1036, doi:10.3762/bjoc.8.115

• example of a more complex alkyne. The azide–alkyne [3 + 2] cycloaddition was catalyzed with copper(II) sulfate pentahydrate and L-ascorbic acid in DMF overnight at room temperature. A solution of EDTA was added to remove the remaining copper cations from the resin. Resin cleavage under acidic conditions

• L-ascorbic acid (0.5 equiv) as reducing agent and copper(II) sulfate pentahydrate (10 mol %). After the terminal alkyne (4 equiv) was added, the reaction mixture was stirred for 22 h at room temperature. The resin was washed with dimethylformamide, methanol and dichloromethane (each solvent 2 mL/100

Highly efficient cyclosarin degradation mediated by a β-cyclodextrin derivative containing an oxime-derived substituent

• Michael Zengerle,
• Florian Brandhuber,
• Christian Schneider,
• Franz Worek,
• Georg Reiter and
• Stefan Kubik

Beilstein J. Org. Chem. 2011, 7, 1543–1554, doi:10.3762/bjoc.7.182

• ][41]. The alkyne 6 required for the synthesis of 2a was obtained from propargyl bromide and 3-formylpyridine oxime (Scheme 6), and those for 2b, 2c, and 2d, following the routes shown in Scheme 7. Reaction of these alkynes with 4 in the presence of copper(II) sulfate, sodium ascorbate and tris[(1

Calix[4]arene-click-cyclodextrin and supramolecular structures with watersoluble NIPAAM-copolymers bearing adamantyl units: “Rings on ring on chain”

• Bernd Garska,
• Monir Tabatabai and
• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, 784–788, doi:10.3762/bjoc.6.83

• pump vacuum. N-Isopropylacrylamide (NIPAAM) 97%, sodium azide (99.5%) and azobisisobutyronitrile (98%) were purchased from Aldrich Chemicals (Germany) and used as received. Copper-(II)-sulfate pentahydrate (99%) was obtained from Carl Roth GmbH & CO., and sodium L(+)-ascorbate (99%) obtained from