Photochemical generation of the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical from caged nitroxides by near-infrared two-photon irradiation and its cytocidal effect on lung cancer cells

• Ayato Yamada,
• Manabu Abe,
• Yoshinobu Nishimura,
• Shoji Ishizaka,
• Masashi Namba,
• Taku Nakashima,
• Kiyofumi Shimoji and
• Noboru Hattori

Beilstein J. Org. Chem. 2019, 15, 863–873, doi:10.3762/bjoc.15.84

• vitro using lung cancer cells. One hundred thousand Lewis lung carcinoma (LLC) cells were seeded into 24-well plates (medium: DMEM) and incubated overnight at 37 °C under an atmosphere of 95% air and 5% CO2. The medium was replaced with fresh phenol-red free DMEM containing various concentrations of 2a

• carcinoma (LLC) cells were seeded into a 24-well plate (medium: DMEM) and incubated overnight at 37 °C in an atmosphere of 95% air and 5% CO2. The medium was replaced with fresh phenol-red free DMEM containing 100 µg/mL of compound 2a. Four hours after various irradiation time of 360 nm light (0, 10, 30, 60

• Lewis lung carcinoma (LLC) cells were seeded into 24-well plate (medium: DMEM) and incubated overnight at 37 °C in an atmosphere of 95% air and 5% CO2. The medium was replaced with fresh phenol-red free DMEM containing 0 or 100 µg/mL of compound 2a. Thirty minutes after 1 min or no exposure of 360 nm

Coordination chemistry and photoswitching of dinuclear macrocyclic cadmium-, nickel-, and zinc complexes containing azobenzene carboxylato co-ligands

• Jennifer Klose,
• Tobias Severin,
• Peter Hahn,
• Alexander Jeremies,
• Jens Bergmann,
• Daniel Fuhrmann,
• Jan Griebel,
• Bernd Abel and
• Berthold Kersting

Beilstein J. Org. Chem. 2019, 15, 840–851, doi:10.3762/bjoc.15.81

• of mixed ligand complexes of the type [M2L(μ-O2CR)]+ [1], where M is a divalent or trivalent metal ion (M = Mn2+, Fe2+, Co2+, Co3+, Ni2+, Zn2+ and Cd2+) and μ-O2CR is a μ1,3-bridging carboxylato ligand (Figure 1). The encapsulation of a functional carboxylate ion by the bowl-shaped [M2L] fragment can

Polyaminoazide mixtures for the synthesis of pH-responsive calixarene nanosponges

• Antonella Di Vincenzo,
• Antonio Palumbo Piccionello,
• Alberto Spinella,
• Delia Chillura Martino,
• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2019, 15, 633–641, doi:10.3762/bjoc.15.59

• interesting to notice the presence in the mixture of dioxygenated products, the formation of which might be justified admitting the reaction of a primary amine group with a dibromide 4 unit and a CO2 molecule (likely absorbed from atmosphere) to afford a 1,3-oxazinan-2-one ring according to Scheme 4. The CO2

Back to the future: Why we need enzymology to build a synthetic metabolism of the future

• Tobias J. Erb

Beilstein J. Org. Chem. 2019, 15, 551–557, doi:10.3762/bjoc.15.49

• in respect to production rate and yield. As an example, several novel level 3 and level 4 pathways for the conversion of CO2 into organic acids were developed recently [13][14]. These pathways are predicted to be more efficient than the naturally evolved Calvin cycle of photosynthesis, because they

• require less energy (ATP, redox power and/or photons) and can be supposedly operated at higher catalytic rates compared to natural carbon fixation. Accordingly, the synthetic CO2-fixation cycles should be able to convert more carbon dioxide with less energy in a given time and hence succeed natural

• photosynthesis in volumetric capacity and energetic efficiency. One of these designs, the so-called CETCH cycle (Figure 2a), a synthetic level 4 pathway for the conversion of CO2 into organic acids, was experimentally realized in vitro by combining 17 enzymes (including three engineered ones) from a total of

Synthesis and fluorescent properties of N(9)-alkylated 2-amino-6-triazolylpurines and 7-deazapurines

• Andrejs Šišuļins,
• Jonas Bucevičius,
• Yu-Ting Tseng,
• Irina Novosjolova,
• Kaspars Traskovskis,
• Ērika Bizdēna,
• Huan-Tsung Chang,
• Sigitas Tumkevičius and
• Māris Turks

Beilstein J. Org. Chem. 2019, 15, 474–489, doi:10.3762/bjoc.15.41

• -7 cells were cultured in RPMI medium supplemented with fetal bovine serum (10%), antibiotic–antimycotic (1.0%). MCF-10A cells were cultured in α-MEM supplemented with FBS (10%), and antibiotic–antimycotic (1.0%). All cells were cultured in an environment equilibrated with 5% CO2 at 37 °C. The cell

• number and viability of the cells were determined by applying the trypan blue exclusion method and Alamar Blue assay, respectively. Following the separated incubation of MCF-7 and MCF-10A cells (7.0 × 104 cells per well) in a culture medium for 24 h at 37 °C containing 5% CO2, each of the culture media

Sigmatropic rearrangements of cyclopropenylcarbinol derivatives. Access to diversely substituted alkylidenecyclopropanes

• Guillaume Ernouf,
• Jean-Louis Brayer,
• Christophe Meyer and
• Janine Cossy

Beilstein J. Org. Chem. 2019, 15, 333–350, doi:10.3762/bjoc.15.29

• was a critical issue which was solved by carrying those intermediate compounds directly in the sigmatropic rearrangement. Byproducts arising from the difluorocyclopropenation reaction (CO2, SO2 and Me3SiF) were simply removed by argon sparging of the reaction mixture and the Ireland–Claisen

Olefin metathesis in multiblock copolymer synthesis

• Maria L. Gringolts,
• Yulia I. Denisova,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

• (cyclohexene carbonate)s was carried out by the β-diiminate (BDI) zinc-catalyzed block copolymerization of functionalized epoxides and CO2 with a norbornenyl-containing initiator (Scheme 5) [68]. The subsequent “grafting through” by ROMP of norbornene resulted in the synthesis of multiblock copolymer brushes

Systematic synthetic study of four diastereomerically distinct limonene-1,2-diols and their corresponding cyclic carbonates

• Hiroshi Morikawa,
• Jun-ichi Yamaguchi,
• Shun-ichi Sugimura,
• Masato Minamoto,
• Yuuta Gorou,
• Hisatoyo Morinaga and
• Suguru Motokucho

Beilstein J. Org. Chem. 2019, 15, 130–136, doi:10.3762/bjoc.15.13

• , syntheses of five-membered cyclic carbonates (5CCs) have been intensively investigated [5][6][7] in terms of utilisation of CO2 and the further reactions to produce functional chemicals such as oxazolizin-2-ones [8] and polyurethanes [9]. For (R)-limonene-derived 5CC (LM5CC), four diastereomers are

• , we report the synthesis of 1a from the trans-isomer of (R)-limonene oxide (LO) and 1d from cis-LO using CO2 and tetrabutylammonium chloride (TBAC) as a catalyst. Both reactions proceeded without any side reactions and produced no unwanted isomers, such as 1c. Though the CO2 pressure employed in our

• previous study was 3 MPa [27], 5 MPa CO2 was applied in the present study to promote a higher consumption of LO. The result showed the isolated yields were improved to 84% yield for 1a and 30% yield for 1d. In our previous report, 1d was reduced by lithium aluminium hydride (LAH) to obtain the

Mechanistic studies of an L-proline-catalyzed pyridazine formation involving a Diels–Alder reaction with inverse electron demand

• Anne Schnell,
• J. Alexander Willms,
• S. Nozinovic and
• Marianne Engeser

Beilstein J. Org. Chem. 2019, 15, 30–43, doi:10.3762/bjoc.15.3

• very easily loses CO2 which causes the signal at m/z 309. This behavior could be confirmed by induced fragmentation experiments (see below). Monitoring the temporal progress of reaction R3 was achieved by taking small samples at regular intervals, diluting and swiftly feeding them into the spectrometer

• oxazolidinone present in large excess. Upon CID of the mass-selected signal for I3 at m/z 353 (Figure 10), only elimination of CO2 was observed. The spectra very much resemble the ones we obtained for ions with the same m/z observed when spraying acetonitrile solutions of 1∙Cl and acetone. These were

• leads back to the ion [I3]+. This ion subsequently loses CO2 as already observed in the CID experiment for [I3]+ (Figure 10). The first pathway thus mimics going back one step in the catalytic cycle. On the other hand, [II3]+ fragments into catalyst 1 by simultaneously cleaving off N2 and the product 3

Repurposing the anticancer drug cisplatin with the aim of developing novel Pseudomonas aeruginosa infection control agents

• Mingjun Yuan,
• Song Lin Chua,
• Yang Liu,
• Daniela I. Drautz-Moses,
• Joey Kuok Hoong Yam,
• Thet Tun Aung,
• Roger W. Beuerman,
• May Margarette Santillan Salido,
• Stephan C. Schuster,
• Choon-Hong Tan,
• Michael Givskov,
• Liang Yang and
• Thomas E. Nielsen

Beilstein J. Org. Chem. 2018, 14, 3059–3069, doi:10.3762/bjoc.14.284

• macrophages (RAW264.7) were maintained in Dulbecco’s modified Eagle’s medium (DMEM) (Life Technologies), supplemented with 10% fetal bovine serum (FBS) (Gibco), in 75 cm2 cell culture flasks at a density of 1.0 × 106 cells mL−1 at 37 °C, 5% CO2 for 72 h. The 5.0 × 106 macrophages per well were seeded in 24

• -well plate (Nunc, Denmark) and grown at 37 °C, 5% CO2 overnight. As previously described [12], macrophages were washed once with PBS and treated with PAO1 in DMEM medium with 0, 3.125, 6.25 and 12.5 µM cisplatin at a multiplicity of infection of 100 bacteria cells: 1 macrophage. As control, the

• macrophages were treated with the T3SS deficient ΔpscJ mutant in DMEM medium. The co-culture was incubated at 37 °C, 5% CO2 for 2 h. The extracellular bacterial cells in DMEM were removed and the infected macrophages were washed 3 times with PBS. Fresh DMEM was added to the infected macrophages and a further

Copper(I)-catalyzed tandem reaction: synthesis of 1,4-disubstituted 1,2,3-triazoles from alkyl diacyl peroxides, azidotrimethylsilane, and alkynes

• Muhammad Israr,
• Changqing Ye,
• Munira Taj Muhammad,
• Yajun Li and
• Hongli Bao

Beilstein J. Org. Chem. 2018, 14, 2916–2922, doi:10.3762/bjoc.14.270

• experimental findings, a possible reaction mechanism is suggested as shown in Scheme 5. In the presence of the Cu(I) catalyst, alkyl diacyl peroxide decomposes into an alkyl radical, CO2, and releases a carboxyl–Cu(II) complex, which undergoes a ligand exchange with azidomethylsilane to form azido–Cu(II

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

• Yo Hiranoi and
• Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

• demonstrate high and/or unique catalytic performances in the epoxide/CA copolymerization [23][32][33][34][35][36][37][38][39]. Recently, we have reported the dinuclear cobalt–salen complexes as catalysts for the copolymerization of epoxides with carbon dioxide (CO2), affording superior catalytic activity

• favorable for a high catalytic activity. Such dependence of the catalytic activity on the absolute configuration contrasts with our previous observation in the epoxide/CO2 copolymerization where the heterochiral (R,R,S,S)-1 showed a much higher catalytic activity than the corresponding homochiral complex (R

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• its decomposition, only CO2 and sulfate are formed [7][8][9][10]. Also, like MSA, p-toluenesulfonic acid (p-TsOH) is non-oxidizing, low cost, and easy to handle. Its physical state is solid, making it easy to work with [11]. According to these benefits, sulfonic acids are used as novel catalysts in

Novel solid-phase strategy for the synthesis of ligand-targeted fluorescent-labelled chelating peptide conjugates as a theranostic tool for cancer

• Sagnik Sengupta,
• Mena Asha Krishnan,
• Premansh Dudhe,
• Ramesh B. Reddy,
• Bishnubasu Giri,
• Sudeshna Chattopadhyay and
• Venkatesh Chelvam

Beilstein J. Org. Chem. 2018, 14, 2665–2679, doi:10.3762/bjoc.14.244

• containing 10% heat-inactivated fetal bovine serum and 1% penicillin streptomycin and CHO-β cells in folate-deficient RPMI 1640 containing 10% heat-inactivated foetal bovine serum and supplemented with 1% penicillin streptomycin. Both the cell lines were grown in a 5% CO2:95% air-humidified atmosphere at 37

Impact of Pseudomonas aeruginosa quorum sensing signaling molecules on adhesion and inflammatory markers in endothelial cells

• Carmen Curutiu,
• Florin Iordache,
• Veronica Lazar,
• Aurelia Magdalena Pisoschi,
• Aneta Pop,
• Mariana Carmen Chifiriuc and
• Alina Maria Hoban

Beilstein J. Org. Chem. 2018, 14, 2580–2588, doi:10.3762/bjoc.14.235

• containing 5% CO2 and 21% O2. To maintain optimal culture conditions, the medium was changed twice a week. Prior the infection with P. aeruginosa and adding QSSMs the endothelial cells were cultured in a medium without antibiotics. Endothelial cells were stimulated with P. aeruginosa PAO1 strain (control

Synthesis of dihydroquinazolines from 2-aminobenzylamine: N³-aryl derivatives with electron-withdrawing groups

• Nadia Gruber,
• Jimena E. Díaz and
• Liliana R. Orelli

Beilstein J. Org. Chem. 2018, 14, 2510–2519, doi:10.3762/bjoc.14.227

• treatment with NaOH/EtOH evolve to the symmetrically substituted 3,4-DHQs [59]. Other authors report the synthesis of N-phenyl-3,4-DHQ by alkylation of sodium formanilide with 2-nitrobenzyl chloride followed by cyclization under reductive conditions [60], or from 2-ABA and CO2 as starting materials in

Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source

• Tetsuaki Fujihara and
• Yasushi Tsuji

Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221

• Tetsuaki Fujihara Yasushi Tsuji Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan 10.3762/bjoc.14.221 Abstract Carbon dioxide (CO2) is one of the most important materials as renewable chemical feedstock. In this

• review, the Co- and Rh-catalyzed transformation of CO2 via carbon–carbon bond-forming reactions is summarized. Combinations of metals (cobalt or rhodium), substrates, and reducing agents realize efficient carboxylation reactions using CO2. The carboxylation of propargyl acetates and alkenyl triflates

• reductant, carboxyzincation and the four-component coupling reaction between alkyne, acrylates, CO2, and zinc occur efficiently. Rh complexes also catalyze the carboxylation of arylboronic esters, C(sp2)–H carboxylation of aromatic compounds, and hydrocarboxylation of styrene derivatives. The Rh-catalyzed

Bioinspired cobalt cubanes with tunable redox potentials for photocatalytic water oxidation and CO₂ reduction

• Zhishan Luo,
• Yidong Hou,
• Jinshui Zhang,
• Sibo Wang and
• Xinchen Wang

Beilstein J. Org. Chem. 2018, 14, 2331–2339, doi:10.3762/bjoc.14.208

• reactions. The “Co4O4” cubane complex Co4O4(CO2Me)4(RNC5H4)4 (R = CN, Br, H, Me, OMe), serves as a molecular catalyst for the efficient and stable photocatalytic water oxidation and CO2 reduction. A comprehensive structure–function analysis emerged herein, highlights the regulation of electronic

• reactions. Keywords: CO2 reduction; cobalt cubane; photocatalysis; water oxidation; water splitting; Introduction The direct conversion of solar energy into chemical fuels (e.g., H2, CO and hydrocarbons) through water splitting and carbon fixation reactions is a sustainable solution to environmental

• and CO2 reduction is regarded as a critical step toward artificial photosynthesis, which can boost the photoconversion efficiency (PCE) significantly [14][15][16][17][18][19]. Molecular catalysts with complex and varied structural motifs are a class of promising catalysts for solar energy conversion

Semi-synthesis and insecticidal activity of spinetoram J and its D-forosamine replacement analogues

• Kai Zhang,
• Jiarong Li,
• Honglin Liu,
• Haiyou Wang and
• Lamusi A

Beilstein J. Org. Chem. 2018, 14, 2321–2330, doi:10.3762/bjoc.14.207

• spinosyn molecule interacts with both gamma-aminobutyric acid (GABA) receptor and nicotine acetylcholine (NACh) receptors [9]. Spinosad and spinetoram can be degraded via a combination of photolysis and microbial action, ultimately producing CO2, H2O, and nitrogen oxides [10]. That suggests that along with

Selective formation of a zwitterion adduct and bicarbonate salt in the efficient CO₂ fixation by N-benzyl cyclic guanidine under dry and wet conditions

• Yoshiaki Yoshida,
• Naoto Aoyagi and
• Takeshi Endo

Beilstein J. Org. Chem. 2018, 14, 2204–2211, doi:10.3762/bjoc.14.194

• Yoshiaki Yoshida Naoto Aoyagi Takeshi Endo Molecular Engineering Institute, Kindai University, 11-6 Kayanomori, Iizuka, Fukuoka 820-8555, Japan 10.3762/bjoc.14.194 Abstract The efficient CO2 fixation by N-benzyl cyclic guanidine 1 was achieved by bubbling dry CO2 through CH3CN at 25 °C for 2 h

• characterized in detail by elemental analysis, FTIR-ATR, solid-state NMR, TGA, and DFT calculation. These analytical results obviously revealed the formation of a zwitterion adduct and bicarbonate salt from N-benzyl cyclic guanidine and CO2. Especially, the zwitterion adduct of the monocyclic guanidine

• derivative and CO2 was isolated and characterized for the first time. Keywords: bicarbonate salt; carbon dioxide adsorption; cyclic guanidine; repeatable capture and release; zwitterion adduct; Introduction Recently, various reactions with CO2 as a cheap and green carbon reagent have been developed not

Cobalt-catalyzed nucleophilic addition of the allylic C(sp³)–H bond of simple alkenes to ketones

• Tsuyoshi Mita,
• Masashi Uchiyama,
• Kenichi Michigami and
• Yoshihiro Sato

Beilstein J. Org. Chem. 2018, 14, 2012–2017, doi:10.3762/bjoc.14.176

• -allylmetal complex that reacts with electrophiles, triggered by allylic C(sp3)–H activation. To this end, Schneider [26], Kanai [27], and we [28][29] reported in 2017 catalytic allylic C(sp3)–H activation of alkenes to react carbonyl electrophiles such as imines, ketones, and CO2 via nucleophilic allylmetal

Graphitic carbon nitride prepared from urea as a photocatalyst for visible-light carbon dioxide reduction with the aid of a mononuclear ruthenium(II) complex

• Kazuhiko Maeda,
• Daehyeon An,
• Ryo Kuriki,
• Daling Lu and
• Osamu Ishitani

Beilstein J. Org. Chem. 2018, 14, 1806–1812, doi:10.3762/bjoc.14.153

• (773–923 K) in air, and was examined as a photocatalyst for CO2 reduction. With increasing synthesis temperature, the conversion of urea into g-C3N4 was facilitated, as confirmed by X-ray diffraction, FTIR spectroscopy and elemental analysis. The as-synthesized g-C3N4 samples, further modified with Ag

• nanoparticles, were capable of reducing CO2 into formate under visible light (λ > 400 nm) in the presence of triethanolamine as an electron donor, with the aid of a molecular Ru(II) cocatalyst (RuP). The CO2 reduction activity was improved by increasing the synthesis temperature of g-C3N4, with the maximum

• activity obtained at 873–923 K. This trend was also consistent with that observed in photocatalytic H2 evolution using Pt-loaded g-C3N4. The photocatalytic activities of RuP/g-C3N4 for CO2 reduction and H2 evolution were thus shown to be strongly associated with the generation of the crystallized g-C3N4

Defining the hydrophobic interactions that drive competence stimulating peptide (CSP)-ComD binding in Streptococcus pneumoniae

• Bimal Koirala,
• Robert A. Hillman,
• Erin K. Tiwold,
• Michael A. Bertucci and
• Yftah Tal-Gan

Beilstein J. Org. Chem. 2018, 14, 1769–1777, doi:10.3762/bjoc.14.151

• ]. Bacterial growth conditions. Bacteria from a freezer stock were grown as described in [19]. Briefly, the bacteria were streaked into a THY agar plate supplemented with 5% donor horse serum and chloramphenicol at a final concentration of 4 µg/mL. The plate was incubated for 8 h in a CO2 incubator (37 °C with

• 5% CO2). Fresh colonies (single colony for D39pcomX::lacZ; multiple colonies for TIGR4pcomX::lacZ) were picked into sterilized cultural tubes containing 5 mL of THY broth supplemented with chloramphenicol at a final concentration of 4 µg/mL and the cultures were incubated in a CO2 incubator

• overnight (15 h). Overnight cultures were then diluted (1:50 for D39pcomX::lacZ; 1:10 for TIGR4pcomX::lacZ) with THY and the resulting solution was incubated in a CO2 incubator for 3–4 hours, until the bacteria reached early exponential stage (0.30–0.35 for D39pcomX::lacZ; 0.20–0.25 for TIGR4pcomX::lacZ) as

Natural and redesigned wasp venom peptides with selective antitumoral activity

• Marcelo D. T. Torres,
• Gislaine P. Andrade,
• Roseli H. Sato,
• Cibele N. Pedron,
• Tania M. Manieri,
• Giselle Cerchiaro,
• Anderson O. Ribeiro,
• Cesar de la Fuente-Nunez and
• Vani X. Oliveira Jr.

Beilstein J. Org. Chem. 2018, 14, 1693–1703, doi:10.3762/bjoc.14.144

• microtiter plates with a density of 2.0 × 104 cells/well at 37 °C and 5% CO2. On the next day, cells were treated with peptides serial dilutions (0.09–50 μmol L–1), incubated in individual microtiter plates for 2 and 24 h and MTT assays were performed after treatment. Human breast epithelial cells MCF-10A

• μg mL−1 streptomycin. The cells were preincubated for 24 h, plated in 96-well microtiter plates with a density of 2.0 × 104 cells/well at 37 °C and 5% CO2. On the next day, cells were treated with peptides serial dilutions (25 to 100 μmol L−1), incubated in individual microtiter plates for 4 and 24 h

Lanyamycin, a macrolide antibiotic from Sorangium cellulosum, strain Soce 481 (Myxobacteria)

• Lucky S. Mulwa,
• Rolf Jansen,
• Dimas F. Praditya,
• Kathrin I. Mohr,
• Patrick W. Okanya,
• Joachim Wink,
• Eike Steinmann and
• Marc Stadler

Beilstein J. Org. Chem. 2018, 14, 1554–1562, doi:10.3762/bjoc.14.132

• serum. Cells were maintained in a 37 °C environment with 5% CO2 supply. Cells were infected with Jc1-derived Renilla reporter viruses in the presence or absence of compounds. Infected cells were lysed and then frozen at −80 °C for 1 hour following measurements of Renilla and Firefly luciferase