Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• Synthesis via intramolecular photochemical [2+2] cycloadditions: In 1985, Machida’s group reported the intramolecular photo-assisted [2 + 2] cycloadditions of N-allylthiosuccinimides 327 applying 1 kW high-pressure mercury lamp irradiation under a nitrogen atmosphere, giving the highly strained tricyclic

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• scale. The scalability of these processes had been limited by the requirement for small-volume batch reactors equipped with mercury vapor discharge lamps [1]. In general, the use of batch reactors on a large-scale is hampered due to the attenuation effect of photon transport (Bouguer–Lambert–Beer law

A method to determine the correct photocatalyst concentration for photooxidation reactions conducted in continuous flow reactors

• Clemens R. Horn and
• Sylvain Gremetz

Beilstein J. Org. Chem. 2020, 16, 871–879, doi:10.3762/bjoc.16.78

• sources over mercury arcs and other light sources commonly used in industry and classical synthetic organic photochemistry. LEDs typically have much narrower emission spectra when compared to these light sources, all of which have broad emission spectra except for low-pressure sodium vapor lamps [15][16

Aldehydes as powerful initiators for photochemical transformations

• Maria A. Theodoropoulou,
• Nikolaos F. Nikitas and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2020, 16, 833–857, doi:10.3762/bjoc.16.76

• ) as the photoinitiator for the photografting of MAA (42) onto high-density polyethylene (39) in an aqueous solution [46]. The light source was a high-pressure mercury UV lamp (2 kW), and a cooling fan was used in order to maintain ambient temperature. Acetaldehyde (36) proved to be more efficient than

• 42 in aqueous solutions [47]. For the cases where the ketones or the aldehydes were not soluble in, or miscible with water, an amount of ethanol was added. The light source employed was a UV high-pressure mercury lamp (2 kW). All aliphatic ketones tested, including acetone (4), butanone, and pentan-2

• Hanovia 450 W mercury arc [17]. If the reaction proceeded stereospecifically, cis-2-butene would have led to the formation of the oxetanes 75a and 75b, while trans-2-butene would have led to the oxetanes 75c and 75d (Scheme 19). It was suggested that the reaction proceeded through a long-lived biradical

Copper-catalyzed O-alkenylation of phosphonates

• Nuria Vázquez-Galiñanes,
• Mariña Andón-Rodríguez,
• Patricia Gómez-Roibás and
• Martín Fañanás-Mastral

Beilstein J. Org. Chem. 2020, 16, 611–615, doi:10.3762/bjoc.16.56

• counterparts has received less attention. Current methodologies for the synthesis of acyclic mixed enol phosphonates include the Perkow-type reaction between phosphonites and α-halocarbonyl compounds [11], the mercury-catalyzed addition of phosphonic acid monoesters to terminal alkynes [12][13] and multistep

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

• and 2.98(1) Å. The C–I···Cl angles are 176.8(6)°, 173.4(6)°, 176.2(6)° and 175.9(6)°. The RXB values are 0.77. These crystal package diagrams display that a bent arrangement of the XB donors are around the central halide anion. The measured bent angles of 2-I, 2-Br and 2-Cl by mercury [46] are 146.38

• applied with the SADABS program [48]. All the structures were solved by SHELXT [49] and refined by SHELXL [50] programs against |F|2 using all data following established refinement strategies [51] through olex2 [52]. Their packing diagrams were prepared by using Mercury [46]. Computational details All

Synthesis and characterization of bis(4-amino-2-bromo-6-methoxy)azobenzene derivatives

• David Martínez-López,
• Amirhossein Babalhavaeji,
• Diego Sampedro and
• G. Andrew Woolley

Beilstein J. Org. Chem. 2019, 15, 3000–3008, doi:10.3762/bjoc.15.296

• PerkinElmer Series 200 pump with a Waters 2487 Dual λ Absorbance Detector connected to an eDAQ PowerChrom 280 recorder. One-dimensional 1H and 13C NMR spectra were recorded on a Varian UnityPlus 500 MHz or Varian Mercury 400 MHz spectrometer. Chemical shifts are reported in ppm, and the signals were

Palladium-catalyzed synthesis and nucleotide pyrophosphatase inhibition of benzo[4,5]furo[3,2-b]indoles

• Hoang Huy Do,
• Saif Ullah,
• Alexander Villinger,
• Joanna Lecka,
• Jean Sévigny,
• Peter Ehlers,
• Jamshed Iqbal and
• Peter Langer

Beilstein J. Org. Chem. 2019, 15, 2830–2839, doi:10.3762/bjoc.15.276

• = 254 nm). Column chromatography was performed on Fluka silica gel 60 (0.063–0.200 mm, 70–320 mesh) on a glass column. For the cation exchange column dowex 50WX8 H+ was used. Melting points (mp) were determined by the instrument Elektrothermal. 1H and 13C NMR spectra («Mercury-300 Varian» 300 MHz with

Iodine-mediated hydration of alkynes on keto-functionalized scaffolds: mechanistic insight and the regiospecific hydration of internal alkynes

• Zachary Lee,
• Brandon R. Jones,
• Nyochembeng Nkengbeza,
• Michael Phillips,
• Kayla Valentine,
• Alexis Stewart,
• Brandon Sellers,
• Nicholas Shuber and
• Karelle S. Aiken

Beilstein J. Org. Chem. 2019, 15, 2747–2752, doi:10.3762/bjoc.15.265

• ; regiospecific hydration; Findings The Kucherov reaction is one of the most well-known approaches for the hydration of alkynes. This reaction, originally published in 1881, requires the use of mercury(II) salts in catalytic quantities [1][2]. Countless studies have shown that mercury-based compounds are

• (II) [7], silver(I) [8], and gold(I)/(III) [9][10][11][12]. While less toxic than mercury, such catalysts are still environmental hazards and tend to be costlier [13][14]. The iodine-mediated hydration described herein is a viable solution to these issues [15][16]. This metal-free method produces

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• by Wattanakit described several approaches for the development of chiral metal electrodes for enantioselective recognition and asymmetric synthesis developed over the past decade [18]. Concurrent with pioneering works in the field of asymmetric induction in electrochemical reduction on chiral mercury

• mixture during the electroreduction of acetophenone on a mercury cathode induces optical activity in the product (alcohol 24a, Scheme 7) [29]. Additionally, pinacol (23) was also obtained via dimerization along with chiral alcohols. The same method was reinvestigated by Wang and Lu in 2013 using a silver

• , conditions B). Based on a strychnine alkaloid-induced asymmetric electroreduction, Kopilov, Kariv and Miller showed that 4- and 2-acetylpyridines (1 and 25) could be reduced to the corresponding pyridylethanols (2 and 26, respectively) in presence of a catalytic amount of the alkaloid on a mercury cathode

Experimental and computational electrochemistry of quinazolinespirohexadienone molecular switches – differential electrochromic vs photochromic behavior

• Eric W. Webb,
• Jonathan P. Moerdyk,
• Kyndra B. Sluiter,
• Benjamin J. Pollock,
• Amy L. Speelman,
• Eugene J. Lynch,
• William F. Polik and
• Jason G. Gillmore

Beilstein J. Org. Chem. 2019, 15, 2473–2485, doi:10.3762/bjoc.15.240

• chemical oxidant (benzoquinone) added to complete the reduction of the dianion to the LW isomer. NMR spectroscopy was performed on samples 5 mm NMR tubes (Wilmad) made of clear quartz (photolyzed samples) or amber pyrex (dark samples) on a Varian Mercury or Bruker AvanceIII 400 MHz NMR. 1H NMR experiments

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

• system. 1H and 13C NMR spectra were recorded on Varian Mercury Plus (1H at 300.03 MHz), Agilent 400-MR DD2 (1H at 399.98 MHz, 13C at 100.58 MHz), Varian Unity Inova (1H at 499.94 MHz) and Bruker Avance Neo (1H at 500.15 MHz, 13C at 125.78 MHz) spectrometers at 25 °C. Chemical shifts (δ) are reported in

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

• as enzyme inhibitors [26] or antitumor agents [27]. These species are also used as valuable synthetic intermediates [28] and chemosensors for mercury and silver [29][30]. The general methods for the synthesis of O-thiocarbamates and dithiocarbamates traditionally rely on substitution reactions of the

Formation of an unexpected 3,3-diphenyl-3H-indazole through a facile intramolecular [2 + 3] cycloaddition of the diazo intermediate

• Andrew T. King,
• Hugh G. Hiscocks,
• Lidia Matesic,
• Mohan Bhadbhade,
• Roger Bishop and
• Alison T. Ung

Beilstein J. Org. Chem. 2019, 15, 1347–1354, doi:10.3762/bjoc.15.134

• refinements were carried out using SHELXL-2014 [35] through Olex2 [36] suite of software. The non-hydrogen atoms were refined anisotropically. Molecular graphics were generated using Mercury [37]. Key crystallographic data and refinement details are presented in Table 1. Crystal structure data

Insertion of [1.1.1]propellane into aromatic disulfides

• Robin M. Bär,
• Gregor Heinrich,
• Martin Nieger,
• Olaf Fuhr and
• Stefan Bräse

Beilstein J. Org. Chem. 2019, 15, 1172–1180, doi:10.3762/bjoc.15.114

• , the conversion could be accelerated in the beginning of the measurement. However, after the work-up of the reaction with radical initiator, an insoluble white solid, presumably longer [n]staffanes, was discovered. When the reaction was performed in a 500 W UV reactor (medium-pressure mercury-vapor

Novel (2-amino-4-arylimidazolyl)propanoic acids and pyrrolo[1,2-c]imidazoles via the domino reactions of 2-amino-4-arylimidazoles with carbonyl and methylene active compounds

• Victoria V. Lipson,
• Tetiana L. Pavlovska,
• Nataliya V. Svetlichnaya,
• Anna A. Poryvai,
• Nikolay Yu. Gorobets,
• Erik V. Van der Eycken,
• Irina S. Konovalova,
• Svetlana V. Shiskina,
• Alexander V. Borisov,
• Vladimir I. Musatov and
• Alexander V. Mazepa

Beilstein J. Org. Chem. 2019, 15, 1032–1045, doi:10.3762/bjoc.15.101

• Specord M-82 spectrometer. The 1H NMR spectra were measured on a Varian Mercury VX-200 (200 MHz) and Bruker AM-400 spectrometer (400 MHz), 13C NMR spectra were measured on a Bruker AM-400 (100 MHz) and Bruker Avance DRX 500 (125 МHz) spectrometers in DMSO-d6, CDCl3 and trifluoroacetic acid (TFA) using TMS

Thiol-free chemoenzymatic synthesis of β-ketosulfides

• Adrián A. Heredia,
• Martín G. López-Vidal,
• Marcela Kurina-Sanz,
• Fabricio R. Bisogno and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2019, 15, 378–387, doi:10.3762/bjoc.15.34

• thiols (Scheme 1) [17][18][19][20][21], other methodologies employing different sulfur sources such as disulfides or silylsulfides have been described, which most of them involves metals, e.g., indium [22], copper [23], mercury [24], or organocatalysts [25]. β-Ketosulfides, in addition, play an important

Carbonylonium ions: the onium ions of the carbonyl group

• Daniel Blanco-Ania and
• Floris P. J. T. Rutjes

Beilstein J. Org. Chem. 2018, 14, 2568–2571, doi:10.3762/bjoc.14.233

• group with mercury to a double bond. “Oxycarbenium ion” can also be found in the literature with this meaning that it correctly describes the same intermediate, although not the more realistic representation of it [30]. Carboxonium ions Other research groups, e.g., Olah’s and Prakash’s, have used the

Diazirine-functionalized mannosides for photoaffinity labeling: trouble with FimH

• Femke Beiroth,
• Tomas Koudelka,
• Thorsten Overath,
• Stefan D. Knight,
• Andreas Tholey and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1890–1900, doi:10.3762/bjoc.14.163

• . Subsequently, the solution was irradiated under ice cooling with a medium pressure mercury vapor lamp for 10 min. Afterwards, 50 µL double distilled water were added and 2 µL of this solution given to 20 µL of a 0.1% trifluoroacetic acid (TFA) solution, desalted with a C18 µZipTip and spotted on a MALDI-plate

• in ACN or DMSO. The ratio ligand to protein was 70:1. The total volume of the reaction was 11 µL either with 50% ACN or 10% DMSO. Ligand and protein were combined and incubated for 10 min at 37 °C and 100 rpm. Afterwards the solution was irradiated under ice cooling with a medium pressure mercury

Water-soluble SNS cationic palladium(II) complexes and their Suzuki–Miyaura cross-coupling reactions in aqueous medium

• Alphonse Fiebor,
• Richard Tia,
• Banothile C. E. Makhubela and
• Henok H. Kinfe

Beilstein J. Org. Chem. 2018, 14, 1859–1870, doi:10.3762/bjoc.14.160

• mixture turned black in the presence of TBAB, we were under the impression that the reaction could have proceeded via formation of palladium nanoparticles as it is common with most palladium catalysed coupling reactions. However, mercury drop experiments provided comparable yields (Table 2, entry 29 and

• 30) under the same reaction conditions ruling out the possibility of a coupling reaction catalysed by palladium nanoparticles [37]. The fact that the reaction mixture remained yellowish in the absence of TBAB and the mercury drop experiments did not lead to an appreciable decrease in yield, the

• ), alkylphosphine (PCP) and aminophosphine (PCP) pincer complexes, and in each of these cases, catalysis was unaffected by metallic mercury during the cross-coupling reactions [41][42][43]. In addition, stable Pd(IV) complexes have been widely prepared and characterised, thus for the catalysis of the pincer

Anomeric modification of carbohydrates using the Mitsunobu reaction

• Julia Hain,
• Patrick Rollin,
• Werner Klaffke and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1619–1636, doi:10.3762/bjoc.14.138

• ]. Stereoselective β-D-mannoside synthesis [60]. TIPS-assisted synthesis of 1,2-cis arabinofuranosides [63]. TIPS: triisopropylsilyl. The Mitsunobu reaction with glycals leads to interesting rearrangement products [69]. Synthesis of disaccharides using mercury(II) bromide as co-activator in the Mitsunobu reaction

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

• layer configuration, where the thickness of the thin layer is tunable in the micrometer range by an implemented micrometer screw. The Bruker Tensor 27 FTIR spectrometer was equipped with an A530/P reflection unit, a liquid nitrogen mercury cadmium telluride detector and was constantly purged with dried

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

• of catalytic mercury iodide; it is a critical step for the formation of the compound 72. Hydrolysis of intermediate 68 led to ketone 69 in high yield containing an acetic acid residue β to the carbonyl group. A sequence of the one-carbon homologation of ketone 69 is followed by isomerization into the

Selective carboxylation of reactive benzylic C–H bonds by a hypervalent iodine(III)/inorganic bromide oxidation system

• Toshifumi Dohi,
• Shohei Ueda,
• Kosuke Iwasaki,
• Yusuke Tsunoda,
• Koji Morimoto and
• Yasuyuki Kita

Beilstein J. Org. Chem. 2018, 14, 1087–1094, doi:10.3762/bjoc.14.94

• replacement for certain heavy-metal oxidizers, such as lead, mercury, and thallium-based salts, due to their low toxicities, high stabilities, operational simplicities, and many other user-friendly characteristics [31][32]. By virtue of their wide array of reactivity patterns, the controllable radical and

2-Iodo-N-isopropyl-5-methoxybenzamide as a highly reactive and environmentally benign catalyst for alcohol oxidation

• Takayuki Yakura,
• Tomoya Fujiwara,
• Akihiro Yamada and
• Hisanori Nambu

Beilstein J. Org. Chem. 2018, 14, 971–978, doi:10.3762/bjoc.14.82

• fundamental and frequently used transformation in organic synthesis. Heavy metal-based oxidants such as chromium(VI), lead(IV), and mercury(II) have been extensively used for this purpose for a long time. However, these oxidants are highly toxic and produce hazardous waste. Recently, hypervalent iodine