Imidazolinium and amidinium salts as Lewis acid organocatalysts

• Oksana Sereda,
• Nicole Clemens,
• Tatjana Heckel and
• René Wilhelm

Beilstein J. Org. Chem. 2012, 8, 1798–1803, doi:10.3762/bjoc.8.205

• hydrogen-bond activation catalysts [18]. The utilization of the soft Lewis basic sulfur groups in this reaction is rare. Often mercury Lewis acids are applied [19][20][21][22] to activate the sulfur group and there is also the risk of desulfurization [23]. The only known asymmetric Diels–Alder reaction

Copper-catalyzed CuAAC/intramolecular C–H arylation sequence: Synthesis of annulated 1,2,3-triazoles

• Rajkumar Jeyachandran,
• Harish Kumar Potukuchi and
• Lutz Ackermann

Beilstein J. Org. Chem. 2012, 8, 1771–1777, doi:10.3762/bjoc.8.202

• , estimated to be >95 % pure, as determined by 1H NMR. Thin-layer chromatography (TLC) was carried out on silica gel 60 F254 aluminum plates (Merck). Chromatography: Merck silica gel 60 (40–63 μm). NMR: Spectra were recorded on Varian Unity 300, Mercury 300 or Inova 500 in the solvent indicated; chemical

A Wittig-olefination–Claisen-rearrangement approach to the 3-methylquinoline-4-carbaldehyde synthesis

• Mukund G. Kulkarni,
• Mayur P. Desai,
• Deekshaputra R. Birhade,
• Yunus B. Shaikh,
• Ajit N. Dhatrak and
• Ramesh Gannimani

Beilstein J. Org. Chem. 2012, 8, 1725–1729, doi:10.3762/bjoc.8.197

• gel (100–200 mesh) was used for column chromatography. IR spectra were recorded on a Perkin Elmer model 1600 series FTIR instrument. 1H and 13C NMR (ppm, TMS, internal standard) in CDCl3 were recorded on a JEOL FX 90Q, Varian Mercury 300 MHz and 75 MHz, respectively. CHN analysis was performed on a

A simple and efficient dual optical signaling chemodosimeter for toxic Hg(II)

• Sabir H. Mashraqui,
• Sapna A. Tripathi,
• Sushil S. Ghorpade and
• Smita R. Britto

Beilstein J. Org. Chem. 2012, 8, 1352–1357, doi:10.3762/bjoc.8.155

• disciplines of biology, medicine and environment [1][2][3][4][5]. Though, mercury and alkylmercury are highly poisonous, mercury ions are also a subject of worldwide concern because of their acute immune-, geno- and neurotoxic effects on human, livestock and marine mammals [6][7][8][9][10][11]. The poisonous

• effects of mercury ions stem from their irreversible binding with the sulfhydryl-containing groups of proteins and enzymes, resulting in clinical problems such as prenatal brain damage, muscle coordination difficulties, lung, kidney and vision disorders. To date, many chemosensors featuring assortments of

• action of hazardous mercury ions in samples containing several background metal ions. In addition to the matrix experiment described above, we studied the effects of individual interferents on the fluorescence response of mercury ions. Therefore, the fluorescence spectra of the probe in the presence of

Synthesis of new pyrrole–pyridine-based ligands using an in situ Suzuki coupling method

• Matthias Böttger,
• Björn Wiegmann,
• Steffen Schaumburg,
• Peter G. Jones,
• Wolfgang Kowalsky and
• Hans-Hermann Johannes

Beilstein J. Org. Chem. 2012, 8, 1037–1047, doi:10.3762/bjoc.8.116

• solvents. NMR: 600 MHz (1H), 151 MHz (13C): Bruker AV2-600 spectrometer. 200 MHz (1H), 50 MHz (13C): Varian Mercury Plus 200. 1H chemical shifts were recorded with tetramethylsilane (TMS) as the internal standard. 13C measurements were taken with the corresponding solvent signal as the reference. J values

Phytoalexins of the Pyrinae: Biphenyls and dibenzofurans

• Cornelia Chizzali and
• Ludger Beerhues

Beilstein J. Org. Chem. 2012, 8, 613–620, doi:10.3762/bjoc.8.68

• 34 species of the Pyrinae, only Sorbus aucuparia formed a phytoalexin, namely aucuparin (3) [20]. Another abiotic elicitor, mercury, caused accumulation of 4'-methoxyaucuparin (10) in Rhaphiolepis umbellata at concentrations higher than after fungal infection [14][19]. So far, no glycosides of

Aryl nitrile oxide cycloaddition reactions in the presence of pinacol boronic acid ester

• Sarah L. Harding,
• Sebastian M. Marcuccio and
• G. Paul Savage

Beilstein J. Org. Chem. 2012, 8, 606–612, doi:10.3762/bjoc.8.67

• halogenation–dehydrohalogenation process is most common, several methods involving direct oxidative dehydrogenation of aldoximes have been reported, including the use of lead tetraacetate [22][23], mercury(II) acetate [24], hypervalent iodine [25][26], and manganese(IV) oxide [27]. We were interested in

Synthesis and biological evaluation of nojirimycin- and pyrrolidine-based trehalase inhibitors

• Davide Bini,
• Francesca Cardona,
• Matilde Forcella,
• Camilla Parmeggiani,
• Paolo Parenti,
• Francesco Nicotra and
• Laura Cipolla

Beilstein J. Org. Chem. 2012, 8, 514–521, doi:10.3762/bjoc.8.58

• solution of (NH4)6Mo7O24 (21 g), Ce(SO4)2 (1 g), conc. H2SO4 (31 mL) in water (500 mL) and then heating to 110 °C for 5 min. Flash column chromatography was performed on silica gel 230–400 mesh (Merck). Routine 1H and 13C NMR spectra were recorded on a Varian Mercury instrument at 400 MHz (1H) and 100.57

A ferrocene redox-active triazolium macrocycle that binds and senses chloride

• Nicholas G. White and
• Paul D. Beer

Beilstein J. Org. Chem. 2012, 8, 246–252, doi:10.3762/bjoc.8.25

• . Tetrabutylammonium salts were stored in a vacuum desiccator under reduced pressure. All other compounds were bought commercially and used as received. Routine NMR spectra were recorded on a Varian Mercury 300 spectrometer with 1H NMR operating at 300 MHz, 13C at 75.5 MHz. Spectra for anion-binding titrations were

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

• pattern at ambient temperature. At lower temperatures, however, the A3X pattern seen for the silver(I) complex changes to an A2BX pattern, indicating that the apparent symmetry is a time-averaged effect. Cragg reported the reaction of 17a with mercury(II) chloride and the X-ray crystal structure of the

Synthesis and characterization of new diiodocoumarin derivatives with promising antimicrobial activities

• Hany M. Mohamed,
• Ashraf H. F. Abd EL-Wahab,
• Ahmed M. EL-Agrody,
• Ahmed H. Bedair,
• Fathy A. Eid,
• Mostafa M. Khafagy and
• Kamal A. Abd-EL-Rehem

Beilstein J. Org. Chem. 2011, 7, 1688–1696, doi:10.3762/bjoc.7.199

• -IR 5300 spectrometer and Perkin Elmer spectrum RXIFT-IR system (ν, cm−1). The 1H NMR spectra at 300 MHz and 13C NMR spectra at 75 MHz were recorded in CDCl3 or DMSO-d6 on a Varian Mercury VX-300 NMR spectrometer. Chemical shifts (δ) are related to that of the solvent. Mass spectra were measured on a

Scalable synthesis of (1-cyclopropyl)cyclopropylamine hydrochloride

• Sergei I. Kozhushkov,
• Alexander F. Khlebnikov,
• Rafael R. Kostikov,
• Dmitrii S. Yufit and
• Armin de Meijere

Beilstein J. Org. Chem. 2011, 7, 1003–1006, doi:10.3762/bjoc.7.113

• (Distortionless Enhancement by Polarization Transfer)] on Bruker AM 250 and Varian Mercury Vx300 instruments in CDCl3 and D2O solutions, CHCl3/CDCl3 and DHO as internal references. EI-MS, ESI-MS and HRMS spectra were measured with Finnigan MAT 95 (70 eV), Finnigan LCQ and Bruker Daltonic APEX IV 7T FTICR

Multicomponent reaction access to complex quinolines via oxidation of the Povarov adducts

• Esther Vicente-García,
• Rosario Ramón,
• Sara Preciado and
• Rodolfo Lavilla

Beilstein J. Org. Chem. 2011, 7, 980–987, doi:10.3762/bjoc.7.110

• , anilines and activated alkenes in a short sequence, involving Povarov MCR and oxidation steps. Experimental General 1H and 13C NMR spectra were recorded on a Varian Mercury 400 spectrometer. Unless otherwise stated, NMR spectra were recorded in CDCl3 solution with TMS as an internal reference. Data for 1H

Intraannular photoreactions in pseudo-geminally substituted [2.2]paracyclophanes

• Henning Hopf,
• Vitaly Raev and
• Peter G. Jones

Beilstein J. Org. Chem. 2011, 7, 658–667, doi:10.3762/bjoc.7.78

• the freeze, pump, and thaw technique. Irradiations were conducted with a high-pressure mercury lamp (150 W) or a halogen torch lamp (1 kW) using water cooling reactor. Synthesis: (1,3-Dioxolan-2-ylmethyl)triphenylphosphonium bromide was prepared according to [24]; 4,15-diformyl[2.2]paracyclophane (9

Gold-catalyzed naphthalene functionalization

• Pedro J. Pérez,
• M. Mar Díaz-Requejo and
• Iván Rivilla

Beilstein J. Org. Chem. 2011, 7, 653–657, doi:10.3762/bjoc.7.77

• ), NaBAr'4 and ethyl 2-diazopropionate were prepared by literature procedures [12][13][14][15][16]. 1H and 13C NMR spectra were recorded on a Varian Mercury 400 spectrometer in CDCl3 as solvent, with chemical shifts (δ) referenced to internal standards. General catalytic experiment Complex 1 (0.025 mmol

Effects of anion complexation on the photoreactivity of bisureido- and bisthioureido-substituted dibenzobarrelene derivatives

• Heiko Ihmels and
• Jia Luo

Beilstein J. Org. Chem. 2011, 7, 278–289, doi:10.3762/bjoc.7.37

• . Preparative column chromatography was performed on MN Silica Gel 60 M (particle size 0.04–0.063 mm, 230–440 mesh). Irradiations were performed with a TQ150 middle-pressure mercury lamp (Heraeus, UV-Consulting Peschl), which was placed inside a quartz cooling tube. The reaction mixture was placed ca. 10–15 cm

Hoveyda–Grubbs type metathesis catalyst immobilized on mesoporous molecular sieves MCM-41 and SBA-15

• Hynek Balcar,
• Tushar Shinde,
• Naděžda Žilková and
• Zdeněk Bastl

Beilstein J. Org. Chem. 2011, 7, 22–28, doi:10.3762/bjoc.7.4

• spectrometer. A Spectralon integration sphere was applied to collect diffuse reflectance spectra of powder samples. Spectralon served also as a reference. Catalyst samples were placed in a quartz cuvette under an Ar atmosphere. 1H (300 MHz) and 13C (75 MHz) NMR spectra were recorded on a Varian Mercury 300

Intramolecular hydroxycarbene C–H-insertion: The curious case of (o-methoxyphenyl)hydroxycarbene

• Dennis Gerbig,
• David Ley,
• Hans Peter Reisenauer and
• Peter R. Schreiner

Beilstein J. Org. Chem. 2010, 6, 1061–1069, doi:10.3762/bjoc.6.121

• approximately 50 mm. A high-pressure mercury lamp (HBO 200, Osram) with a monochromator (Bausch & Lomb) was used for irradiation. Experiments with deuterated acid were conducted accordingly. (o-Methoxyphenyl)glyoxylic acid (6) [25]. To a solution of 3.00 g (20.0 mmol) o-methoxyacetophenone in absolute pyridine

Redox-active tetrathiafulvalene and dithiolene compounds derived from allylic 1,4-diol rearrangement products of disubstituted 1,3-dithiole derivatives

• Filipe Vilela,
• Peter J. Skabara,
• Christopher R. Mason,
• Thomas D. J. Westgate,
• Asun Luquin,
• Simon J. Coles and
• Michael B. Hursthouse

Beilstein J. Org. Chem. 2010, 6, 1002–1014, doi:10.3762/bjoc.6.113

• rotation and therefore isomerisation. It can be anticipated that the two isomers will not differ significantly in their electrochemical properties (see below). Compound 3 was trans-chalcogenated by mercury(II)acetate in a mixture of acetic acid and CH2Cl2 to give the oxo derivative 26 in 89% yield

• mixture of 3:1 by volume CH2Cl2:glacial acetic acid (100 ml) with magnetic stirring. Mercury (II) acetate (0.236 g, 7.423 × 10−4 mol) was added which caused an immediate lightening of the yellow solution and the formation of a white precipitate. The reaction was stirred at room temperature for 4 h then

Towards racemizable chiral organogelators

• Jian Bin Lin,
• Debarshi Dasgupta,
• Seda Cantekin and
• Albertus P. H. J. Schenning

Beilstein J. Org. Chem. 2010, 6, 960–965, doi:10.3762/bjoc.6.107

• Varian Mercury NMR Spectrometer. IR spectra were measured on a Perkin Elmer 1600 FT-IR. MALDI-TOF MS spectra were measured on a Perseptive DE Voyager Mass Spectrometer with α-cyano-4-hydroxycinnamic acid as the matrix. Synthesis Phenylglycinamide R-2, S-2: The ester salt R-1, S-1 (5.04 g, 25 mmol) was

Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

• Vladimir N. Boiko

Beilstein J. Org. Chem. 2010, 6, 880–921, doi:10.3762/bjoc.6.88

• chlorination with only minor amounts of bis-(CF3S) products (Scheme 12). Aryl magnesium [78] and -mercury [79] compounds have been employed for the introduction of CF3S groups. Such reactions proceed in ether or THF at low temperatures; however, the yields of aryltrifluoromethyl sulfides do not exceed 50–60

• carrying out the synthesis of aryltrifluoromethyl sulfides by generation CuSCF3 (from trifluoromethylthio mercury and -copper) in situ with the aryl halides. This not only reduces the number of steps but also increases the overall efficiency (Scheme 26). Aryl bromides can also be used but require higher

Shelf-stable electrophilic trifluoromethylating reagents: A brief historical perspective

• Norio Shibata,
• Andrej Matsnev and
• Dominique Cahard

Beilstein J. Org. Chem. 2010, 6, No. 65, doi:10.3762/bjoc.6.65

• derivatives from −70 °C. Decomposition of the salts is rapid at –30 °C. However, reaction with O- and N-centered nucleophiles was possible with in situ generated trifluoromethyloxonium salts obtained by irradiation of 19 with a high-pressure mercury lamp at low temperature in dichloromethane; other

Synthesis, characterization and photoinduced curing of polysulfones with (meth)acrylate functionalities

• Cemil Dizman,
• Sahin Ates,
• Lokman Torun and
• Yusuf Yagci

Beilstein J. Org. Chem. 2010, 6, No. 56, doi:10.3762/bjoc.6.56

• instrument. Photocalorimetry (Photo-DSC) The photo-differential scanning calorimetry (Photo-DSC) measurements were carried out by means of a modified Perkin-Elmer Diamond DSC equipped with a high pressure mercury arc lamp (320–500 nm). A uniform UV light intensity was delivered across the DSC cell to the

(Pseudo)amide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties

• José L. Jiménez Blanco,
• Fernando Ortega-Caballero,
• Carmen Ortiz Mellet and
• José M. García Fernández

Beilstein J. Org. Chem. 2010, 6, No. 20, doi:10.3762/bjoc.6.20

• followed by treatment with yellow mercury (II) oxide [68]. There are two general strategies to access pseudoamide-type oligosaccharide mimics: i) nucleophilic addition of sugar derivatives to carbohydrate isocyanates, isothiocyanates or isocyanides; and ii) conversion of sugar azides into glycosyl

Synthesis of a new class of aminocyclitol analogues with the conduramine D-2 configuration

• Latif Kelebekli,
• Yunus Kara and
• Murat Celik

Beilstein J. Org. Chem. 2010, 6, No. 15, doi:10.3762/bjoc.6.15

• cyclooctatetraene (8) by the addition of mercury(II) acetate [31]. Tetraphenylporphyrin sensitized photooxygenation of diacetoxydiene 9 with singlet oxygen gave the expected endoperoxide 10. Reduction of the peroxide bond in 10 was performed with thiourea under very mild conditions to give the cis-diol 11 in 99