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

Spectroelectrochemical studies on the effect of cations in the alkaline glycerol oxidation reaction over carbon nanotube-supported Pd nanoparticles

• Dennis Hiltrop,
• Steffen Cychy,
• Karina Elumeeva,
• Wolfgang Schuhmann and
• Martin Muhler

Beilstein J. Org. Chem. 2018, 14, 1428–1435, doi:10.3762/bjoc.14.120

• from starch, sugar or oils and fats [2][3]. The transesterification of oils and fats produces glycerol as a byproduct, which requires further processing to reduce the costs of biofuels [4]. The comparably high energy density of glycerol of 5965 Wh L−1 assuming its total oxidation to CO2 suggests its

Design and biological characterization of novel cell-penetrating peptides preferentially targeting cell nuclei and subnuclear regions

• Anja Gronewold,
• Mareike Horn and
• Ines Neundorf

Beilstein J. Org. Chem. 2018, 14, 1378–1388, doi:10.3762/bjoc.14.116

• the molar ellipticity at 222 nm and 207 nm was used to confirm an α-helical structure of peptides [25]. Cell culturing All cell lines were grown in sterile culture dishes in a CO2 incubator (5% CO2) at 37 °C. HeLa and MCF-7 were grown in RPMI-1640 medium containing 10% fetal bovine serum (FBS) and 4

A three-armed cryptand with triazine and pyridine units: synthesis, structure and complexation with polycyclic aromatic compounds

• Claudia Lar,
• Adrian Woiczechowski-Pop,
• Attila Bende,
• Ioana Georgeta Grosu,
• Natalia Miklášová,
• Elena Bogdan,
• Niculina Daniela Hădade,
• Anamaria Terec and
• Ion Grosu

Beilstein J. Org. Chem. 2018, 14, 1370–1377, doi:10.3762/bjoc.14.115

• [32] revealed its selective absorption ability for N2 and CO2 in the solid state. The low complexation ability of cryptand 1 in solution for aromatic guests is due to the unfavorable conformation of the 1,3,5-triphenylbenzene central units in which the peripheral aromatic rings are twisted with

[3 + 2]-Cycloaddition reaction of sydnones with alkynes

• Veronika Hladíková,
• Jiří Váňa and
• Jiří Hanusek

Beilstein J. Org. Chem. 2018, 14, 1317–1348, doi:10.3762/bjoc.14.113

• absence of light. Depending on the temperature, a new reaction pathway involving benzylic group migration, CO2 extrusion and final cycloaddition was proposed (Scheme 4). Kinetics and mechanism of thermal cycloaddition The kinetics and reaction mechanism of the thermal cycloaddition between 4-methyl-3

• bicyclic intermediate via a concerted [3 + 2]-cycloaddition followed by its very fast decomposition (extrusion of CO2) via a retro-Diels–Alder [4 + 2]-cycloaddition. The almost spontaneous extrusion of CO2 is caused by an energetically favorable aromatization occurring in this step leading to the formation

• its slow decomposition to pyrazole and CO2. Such ambiguous substitution effects are therefore worthy of further investigations. Photochemical reaction of sydnones with symmetrical alkynes In 1966 Krauch et al. [59] dealt with irradiation (using a high-pressure Hg lamp) of benzene or dioxane solutions

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

Mechanochemistry of nucleosides, nucleotides and related materials

• Olga Eguaogie,
• Joseph S. Vyle,
• Patrick F. Conlon,
• Manuela A. Gîlea and
• Yipei Liang

Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81

• derivatives, Sikchi and Hultin contrived an attritor-type mill (Figure 1c) to facilitate the use of neat reagents and vent CO2 (closed vessels were reported to break) [19]. Efficient gram-scale Boc protection of amine and carboxylic acid functions was thereby effected (Scheme 3). This chemistry was further

Phosphodiester models for cleavage of nucleic acids

• Satu Mikkola,
• Tuomas Lönnberg and
• Harri Lönnberg

Beilstein J. Org. Chem. 2018, 14, 803–837, doi:10.3762/bjoc.14.68

Synthesis and in vitro biochemical evaluation of oxime bond-linked daunorubicin–GnRH-III conjugates developed for targeted drug delivery

• Sabine Schuster,
• Beáta Biri-Kovács,
• Bálint Szeder,
• Viktor Farkas,
• László Buday,
• Zsuzsanna Szabó,
• Gábor Halmos and
• Gábor Mező

Beilstein J. Org. Chem. 2018, 14, 756–771, doi:10.3762/bjoc.14.64

• plastic culture dishes at 37 °C with a humidified atmosphere containing 5% CO2/95% air. Stability of GnRH-III bioconjugates in cell culture medium The GnRH-III bioconjugates were dissolved in water to a concentration of 2.5 mg/mL followed by the dilution with serum-free cell culture medium (final

Latest development in the synthesis of ursodeoxycholic acid (UDCA): a critical review

• Fabio Tonin and
• Isabel W. C. E. Arends

Beilstein J. Org. Chem. 2018, 14, 470–483, doi:10.3762/bjoc.14.33

• most used enzymes for the cofactor regeneration are glucose dehydrogenase (glucose to glucuronic acid), lactate dehydrogenase (pyruvate to lactate), glutamate dehydrogenase (α-ketoglutarate to glutamate) and formate dehydrogenase (formate to CO2). In particular, the last enzyme is interesting because

• formate is cheap and, because of the gaseous nature of CO2 as product, the equilibrium of the reaction is entropically favoured. Pedrini et al. in 2006 [33] reported the successful epimerization of CDCA to UDCA using a redox-neutral cascade reaction, with two NAD+-dependent dehydrogenases. In this way the

Synthesis of fluoro-functionalized diaryl-λ³-iodonium salts and their cytotoxicity against human lymphoma U937 cells

• Prajwalita Das,
• Etsuko Tokunaga,
• Hidehiko Akiyama,
• Hiroki Doi,
• Norimichi Saito and
• Norio Shibata

Beilstein J. Org. Chem. 2018, 14, 364–372, doi:10.3762/bjoc.14.24

• × 105 cells/well) and incubated at 37 °C for 24 h. MTT reagent (10 μL) was added to each well. After mixing gently, the cells were incubated for 3 h at 37 °C in a CO2 incubator. The culture medium was aspirated and the crystal-dissolving solution (100 μL) was added to each well and mixed. Finally, the

Progress in copper-catalyzed trifluoromethylation

• Guan-bao Li,
• Chao Zhang,
• Chun Song and
• Yu-dao Ma

Beilstein J. Org. Chem. 2018, 14, 155–181, doi:10.3762/bjoc.14.11

• DMF decomposed into Cu2+, difluorocarbene and fluoride with the release of SO2 and CO2. Then, difluorocarbene and fluoride combined into a CF3 species in the presence of Cu2+ and Cu. In contrast with the majority of previously reported copper-mediated trifluoromethylation reactions of haloarenes

The photodecarboxylative addition of carboxylates to phthalimides as a key-step in the synthesis of biologically active 3-arylmethylene-2,3-dihydro-1H-isoindolin-1-ones

• Ommid Anamimoghadam,
• Saira Mumtaz,
• Anke Nietsch,
• Gaetano Saya,
• Cherie A. Motti,
• Jun Wang,
• Peter C. Junk,
• Ashfaq Mahmood Qureshi and
• Michael Oelgemöller

Beilstein J. Org. Chem. 2017, 13, 2833–2841, doi:10.3762/bjoc.13.275

• excess amounts to suppress competing ‘simple’ decarboxylation (-CO2− ↔ -H exchange) reactions to the corresponding toluene derivatives [25]. Following the established protocol and utilizing a 1:1 acetone/water mixture as reaction medium [27][30], irradiations with UVB light (300 ± 30 nm) for 4 hours

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

Pyrene–nucleobase conjugates: synthesis, oligonucleotide binding and confocal bioimaging studies

• Artur Jabłoński,
• Yannic Fritz,
• Hans-Achim Wagenknecht,
• Rafał Czerwieniec,
• Tytus Bernaś,
• Damian Trzybiński,
• Krzysztof Woźniak and
• Konrad Kowalski

Beilstein J. Org. Chem. 2017, 13, 2521–2534, doi:10.3762/bjoc.13.249

• cells were cultured for 48 h after seeding in Petri dishes with glass bottom (MaTek), reaching approximately 50% confluency. The cells were grown in Dulbeco’s minimal essential medium (DMEM) with 5% FCS, at 5% CO2 and 37 °C. The same medium was used to perform all microscopy experiments. Directly before

Hydrolysis, polarity, and conformational impact of C-terminal partially fluorinated ethyl esters in peptide models

• Vladimir Kubyshkin and
• Nediljko Budisa

Beilstein J. Org. Chem. 2017, 13, 2442–2457, doi:10.3762/bjoc.13.241

• , 2.5 Hz, α-CH), 3.73 (s, OCH3), 3.47 (ddd, JHH = 11.6, 8.5, 3.5 Hz, δ-CH), 3.41 (dt, JHH = 11.4, 8.4 Hz, δ-CH), 2.27 and 2.15 (two m, β-CH2), 1.93 (s, CH3C=O), 1.89 and 1.79 (two m, γ-CH2); 13C{1H} NMR (D2O, 126 MHz) δ s-trans, 175.0 (s, CO2), 173.0 (s, N-C=O), 59.0 (s, α-CH), 52.9 (s, OCH3), 48.4 (s

• , δ-CH2), 29.2 (s, β-CH2), 24.2 (s, γ-CH2), 21.2 (s, CH3); s-cis, 174.6 (s, CO2), 173.4 (s, N-C=O), 60.7 (s, α-CH), 53.2 (s, OCH3), 46.6 (s, δ-CH2), 30.6 (s, β-CH2), 22.3 (s, γ-CH2), 21.2 (s, CH3); HRMS (ESI-orbitrap): [M + H]+ calcd for C8H14NO3, 172.0968; found, 172.0968; [α]D25 −83 (c 2.0, CHCl3

• ), 4.20 (q, JHH = 7.2 Hz, OCH2), 3.47 (ddd, JHH = 11.5, 8.7, 3.7 Hz, δ-CH), 3.41 (dt, JHH = 11.5, 8.3 Hz, δ-CH), 2.28 and 2.15 (two m, β-CH2), 1.93 (s, CH3C=O), 1.90 and 1.80 (two m, γ-CH2); 13C{1H} NMR (D2O, 176 MHz) δ s-trans, 174.7 (s, CO2), 173.0 (s, N-C=O), 62.6 (s, OCH2), 59.3 (s, α-CH), 48.5 (s, δ

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• phthalocyanines. TFEO-Pc is soluble not only in general organic solvents but also in liquid carbon dioxide (CO2) and supercritical CO2 [55]. These forms of CO2 have attracted attention as solvents which do not discharge volatile organic compounds (VOCs), and are expected to replace organic solvents as a

• countermeasure to VOC emissions [56][57][58]. Phthalocyanines that show solubility in CO2 are useful for industrial applications because they can be applied without using an organic solvent [59][60]. The plus and minus signs shown in Table 1 express solubility, where (+) means readily soluble, (−) means

• sparingly soluble, (++) means very high solubility, and (±) means moderate solubility. After conducting solubility studies on various phthalocyanines, only phthalocyanine in which all positions were substituted with trifluoroethoxy groups showed high solubility in both liquid CO2 and supercritical CO2. On

A mechanochemical approach to access the proline–proline diketopiperazine framework

• Nicolas Pétry,
• Hafid Benakki,
• Eric Clot,
• Pascal Retailleau,
• Farhate Guenoun,
• Fatima Asserar,
• Chakib Sekkat,
• Thomas-Xavier Métro,
• Jean Martinez and
• Frédéric Lamaty

Beilstein J. Org. Chem. 2017, 13, 2169–2178, doi:10.3762/bjoc.13.217

• it would avoid a potential pressure build-up (release of CO2) which could occur with NaHCO3. Noteworthy, no epimerization could be detected by NMR or HPLC analyses. Both peptides 7 and 8 were then deprotected and cyclized into the corresponding diketopiperazine 9. Palladium-catalyzed hydrogenolysis