The direct oxidative diene cyclization and related reactions in natural product synthesis

• Juliane Adrian,
• Leona J. Gross and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2016, 12, 2104–2123, doi:10.3762/bjoc.12.200

• ) and then successfully connected in a silicon-tethered ring closing metathesis (RCM) [98] to provide the main backbone of cis-sylvaticin (40). Moreover, in 2009, Brown and co-workers reported on a short synthesis of the non-adjacent bis-THF core of cis-sylvaticin (40) making use of a permanganate

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

Synthesis and characterization of benzodithiophene and benzotriazole-based polymers for photovoltaic applications

• Desta Gedefaw,
• Marta Tessarolo,
• Margherita Bolognesi,
• Mario Prosa,
• Renee Kroon,
• Wenliu Zhuang,
• Patrik Henriksson,
• Kim Bini,
• Ergang Wang,
• Michele Muccini,
• Mirko Seri and
• Mats R. Andersson

Beilstein J. Org. Chem. 2016, 12, 1629–1637, doi:10.3762/bjoc.12.160

• recorded by a Keithley 236 source-measure unit under AM1.5G simulated solar irradiation, 100 mW/cm2 (Abet Technologies Sun 2000 Solar Simulator). The light intensity was determined by a calibrated silicon solar cell fitted with a KG5 color glass filter to bring spectral mismatch to unity. The active area

Star-shaped and linear π-conjugated oligomers consisting of a tetrathienoanthracene core and multiple diketopyrrolopyrrole arms for organic solar cells

• Hideaki Komiyama,
• Chihaya Adachi and
• Takuma Yasuda

Beilstein J. Org. Chem. 2016, 12, 1459–1466, doi:10.3762/bjoc.12.142

• AM 1.5G solar illumination at 100 mW cm−2 (1 sun), using a Xe lamp-based Bunko-Keiki SRO-25 GD solar simulator. The light intensity was calibrated using a standard silicon photovoltaic reference cell. Chemical structures of TTA-DPP4 and TTA-DPP2. HOMO and LUMO distributions, calculated energy levels

Biradical vs singlet oxygen photogeneration in suprofen–cholesterol systems

• Fabrizio Palumbo,
• Francisco Bosca,
• Isabel M. Morera,
• Inmaculada Andreu and
• Miguel A. Miranda

Beilstein J. Org. Chem. 2016, 12, 1196–1202, doi:10.3762/bjoc.12.115

• photolysis cell in right-angle geometry. An excimer laser (LEXTRA50 Lambda Physik) was used for the excitation at 308 nm (laser excitation at 5 low-pulse energies for each molecule). A 5 mm thick (5 cm in diameter) 1050 nm cut-off silicon filter and a 1270 nm interference filter were placed between the diode

Syntheses of dibenzo[d,d']benzo[2,1-b:3,4-b']difuran derivatives and their application to organic field-effect transistors

• Minh Anh Truong and
• Koji Nakano

Beilstein J. Org. Chem. 2016, 12, 805–812, doi:10.3762/bjoc.12.79

• conventional silicon-based semiconductors. Organic semiconducting materials can be used as active layers in organic field-effect transistors (OFETs) [1][2][3][4][5][6][7], organic light-emitting diodes (OLEDs) [8][9][10], and organic photovoltaics (OPVs) [11][12]. Among many organic semiconducting materials so

Art, auto-mechanics, and supramolecular chemistry. A merging of hobbies and career

• Eric V. Anslyn

Beilstein J. Org. Chem. 2016, 12, 362–376, doi:10.3762/bjoc.12.40

• beads placed in micromachined divots on a silicon chip (Figure 9A), and solvents and samples were introduced to the system via an external HPLC [69]. While the miniature nature of the system was intriguing, such a device was going to be difficult for supramolecular chemists to adopt. More user-friendly

Regioselective palladium-catalyzed ring-opening reactions of C1-substituted oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylates

• Michael Edmunds,
• Mohammed Abdul Raheem,
• Rebecca Boutin,
• Katrina Tait and
• William Tam

Beilstein J. Org. Chem. 2016, 12, 239–244, doi:10.3762/bjoc.12.25

• bridgehead carbon appears to impact the reactions’ outcome by hindering access to the site of carbo-palladation. SiMe3 gave a moderate yield of 64% (Table 3, entry 4). The silicon–carbon bond is longer than carbon–carbon bonds, making TMS less bulky than its hydrocarbon counterparts. Both of the electron

Bright molecules for sensing, computing and imaging: a tale of two once-troubled cities

• A. Prasanna de Silva

Beilstein J. Org. Chem. 2015, 11, 2774–2784, doi:10.3762/bjoc.11.298

• modern manifestations of these processors are the logic gates cut from silicon. Of course, stored-program computers (as the name suggests) require software in order to command and coordinate complex computations. I was fortunate to receive programming instruction from Gihan Wickramanayake (University of

• interface somewhat akin to those found in a touch-screen of a mobile telephone or in a mouse-driven screen of a stored-program computer. The treated paper could build an image after receiving a projection of the object. We do this by using a photoacid generator 6 (used to sculpt features in silicon chips

Pyridylidene ligand facilitates gold-catalyzed oxidative C–H arylation of heterocycles

• Kazuhiro Hata,
• Hideto Ito,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2015, 11, 2737–2746, doi:10.3762/bjoc.11.295

• mmol), 2-iodosobenzoic acid (IBA, 53 mg, 0.20 mmol), 10-camphorsulfonic acid (CSA) (47 mg, 0.20 mmol) and a stir bar were placed in a screw test tube, and dry CHCl3/MeOH (1.0 mL/0.10 mL) was added under N2 atmosphere. The tube was sealed with a cap equipped with a Teflon®-coated silicon rubber septum

• added under N2 atmosphere. The tube was sealed with a cap equipped with a Teflon®-coated silicon rubber septum and heated at 65 °C for 30 min. After cooling to room temperature, LiCl (8.4 mg, 0.20 mmol) was added. 1,1,2,2-Tetrachloroethane was added as an internal standard and an NMR yield of AuCl3(PyC

Copper-catalyzed stereoselective conjugate addition of alkylboranes to alkynoates

• Takamichi Wakamatsu,
• Kazunori Nagao,
• Hirohisa Ohmiya and
• Masaya Sawamura

Beilstein J. Org. Chem. 2015, 11, 2444–2450, doi:10.3762/bjoc.11.265

• , 0.289 mmol) and (9-BBN-H)2 (33.6 mg, 0.138 mmol) were placed in a vial containing a magnetic stirring bar. The vial was sealed with a Teflon®-coated silicon rubber septum, and the vial was evacuated and filled with argon. 1,4-Dioxane (0.4 mL) was added to the vial, and the mixture was stirred at 60 °C

• for 1 h to prepare an alkylborane 2a. Meanwhile, CuOAc (1.5 mg, 0.0125 mmol), P(OPh)3 (6.9 μL, 0.025 mmol) and t-BuOK (1.4 mg, 0.0125 mmol) were placed in another vial. The vial was sealed with a Teflon®-coated silicon rubber septum, evacuated, and then filled with argon. After 1,4-dioxane (0.6 mL

Size-controlled and redox-responsive supramolecular nanoparticles

• Raquel Mejia-Ariza,
• Gavin A. Kronig and
• Jurriaan Huskens

Beilstein J. Org. Chem. 2015, 11, 2388–2399, doi:10.3762/bjoc.11.260

• images were taken with a Carl Zeiss Merlin scanning electron microscope. The samples were prepared by drop-casting 10 μL of a SNP solution onto a silicon wafer. After 60 s, excess of water was removed by filter paper. The particle dimensions are obtained from SEM images with ImageJ software. For each

Olefin metathesis in air

• Lorenzo Piola,
• Fady Nahra and
• Steven P. Nolan

Beilstein J. Org. Chem. 2015, 11, 2038–2056, doi:10.3762/bjoc.11.221

• conducted in water [31][32]. They discovered that Ru(H2O)6(tos)2 could polymerize 7-oxanorbonene 1 in water under air (Scheme 1). In 1991, Marciniec and Pietraszuck reported the catalytic activity of RuCl2(PPh3)3 in the self-metathesis of silicon-contaning olefins. The reactions were performed with 1 mol

Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics

• Alexander L. Kanibolotsky,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1749–1766, doi:10.3762/bjoc.11.191

• -type semiconductor in OFETs using two solvents for spin-coating – chloroform and chlorobenzene [93]. A bottom contact, bottom gate device configuration was used with an n-doped silicon gate and a SiO2 dielectric layer. After annealing at 120 °C, AFM imaging indicated a closely packed grain-like surface

A hybrid electron donor comprising cyclopentadithiophene and dithiafulvenyl for dye-sensitized solar cells

• Gleb Sorohhov,
• Chenyi Yi,
• Michael Grätzel,
• Silvio Decurtins and
• Shi-Xia Liu

Beilstein J. Org. Chem. 2015, 11, 1052–1059, doi:10.3762/bjoc.11.118

• unit. Keywords: donor–acceptor systems; dye-sensitized solar cells; electrochemistry; intramolecular charge transfer; Knoevenagel reaction; tetrathiafulvalene; Introduction Dye-sensitized solar cells (DSSCs) have been intensively investigated as an alternative to silicon-based solar cells [1][2][3][4

Is organic chemistry science – and does this question make any sense at all?

• Andreas Kirschning and
• Thomas A. C. Reydon

Beilstein J. Org. Chem. 2015, 11, 893–896, doi:10.3762/bjoc.11.100

• origin of chirality in bio(macro)molecules and thus in life [12]; the question why biomolecules on earth are based on carbon backbones and not on silicon; the question whether one could imagine other forms of molecular architectures that make up self-repeating systems that develop under evolutionary

Adsorption mechanism and valency of catechol-functionalized hyperbranched polyglycerols

• Stefanie Krysiak,
• Qiang Wei,
• Klaus Rischka,
• Andreas Hartwig,
• Rainer Haag and
• Thorsten Hugel

Beilstein J. Org. Chem. 2015, 11, 828–836, doi:10.3762/bjoc.11.92

• backbone), 39.13 (COCH2CH2C), 37.57 (COCH2CH2C), 32.31 (COCH2CH2C), 31.30 (COCH2CH2C), 24.46 (CCH2CH3 of starter), 7.26 (CCH2CH3 of starter) ppm. TiO2 surface TiO2 slides were prepared by sputtering titanium onto silicon wafers. The sputter process was performed using a commercially available radio

• GMBH, Kirchheim, Germany) and afterwards rinsed with ultrapure water. Tip functionalization The molecule is functionalized to the tip through covalent bonds in a similar manner as previously described [2]. Silicon nitride cantilevers (MLCT, Bruker SPM probes, Camarillo, USA) were first activated in an

Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

• Katherine M. Byrd

Beilstein J. Org. Chem. 2015, 11, 530–562, doi:10.3762/bjoc.11.60

• high enantioselectivities. Though carbon nucleophiles are used in the majority of the copper-catalyzed ECA reactions of α,β-unsaturated amides and lactams, Procter and co-workers have expanded this methodology to the addition of silicon [96]. This reaction is particularly useful because the silyl group

• can be transformed into a number of functional groups [97]. In Procter’s work, they used a Cu(I)–NHC (N-heterocyclic carbene) system to catalyze the asymmetric transfer of silicon from PhMe2SiBpin [98][99] to α,β-unsaturated amides and lactams through activation of the Si–B bond [96] (Scheme 10

• ). Scheme 10 shows selected examples of the α,β-unsaturated lactams and amides that were used for the 1,4-silylation. Overall, the reactions were achieved in both high yields and enantioselectivities with a variety of substrates. In addition to silicon, much work has been done on the asymmetric 1,4-additon

Synthesis and surface grafting of a β-cyclodextrin dimer facilitating cooperative inclusion of 2,6-ANS

• Lars W. Städe,
• Thorbjørn T. Nielsen,
• Laurent Duroux,
• Reinhard Wimmer,
• Kyoko Shimizu and
• Kim L. Larsen

Beilstein J. Org. Chem. 2015, 11, 514–523, doi:10.3762/bjoc.11.58

• fluorescence spectroscopy that the inclusion of the fluorescent guest into both cavities of the β-CD dimer is maintained when grafted onto a solid surface. Keywords: 2,6-ANS; β-cyclodextrin dimer; silicon dioxide; surface grafting; total internal reflection fluorescence spectroscopy; Introduction Since the

• accessibility for inclusion-complex formation [13]. The research presented here aims to bring the cooperative effects of β-CD dimers to solid silicon dioxide surfaces. Modification of these surfaces allows the introduction of the extraordinary binding affinity and selectivity of CD dimers to silicon wafer

• technology and allows the potential cooperative effects to be exploited within chromatographic applications by grafting to silica gels. Further, silicon dioxide surfaces in the form of quartz and glass allow the detection and monitoring of binding events by optical techniques such as fluorescence

The Shono-type electroorganic oxidation of unfunctionalised amides. Carbon–carbon bond formation via electrogenerated N-acyliminium ions

• Alan M. Jones and
• Craig E. Banks

Beilstein J. Org. Chem. 2014, 10, 3056–3072, doi:10.3762/bjoc.10.323

• of the generated reactive intermediates and assist in the formation of the desired products. Tin, silicon or sulfur-based electroauxiliaries have proved useful in this endeavour. Yoshida and co-workers developed an organothio electroauxiliary that is selectively cleaved under anodic oxidation

• conditions [32][33]. Although the introduction of an electroauxiliary requires an additional synthetic step to prepare, the resulting carbon–tin, carbon–silicon or carbon–sulfur bond has a less positive oxidation potential than an unfunctionalised carbamate. Therefore, exquisite control can be exerted on the

• –silicon bond (when an electroauxiliary is present) or direct carbon–hydrogen bond fission to afford the α-methoxylated product (Scheme 10) [67][68]. The direct anodic oxidation reaction to afford the N-acyliminium ion can be intercepted with a carbon nucleophile enantioselectively when a chiral auxiliary

Organic chemistry on surfaces: Direct cyclopropanation by dihalocarbene addition to vinyl terminated self-assembled monolayers (SAMs)

• Malgorzata Adamkiewicz,
• David O’Hagan and
• Georg Hähner

Beilstein J. Org. Chem. 2014, 10, 2897–2902, doi:10.3762/bjoc.10.307

• -SiCl3 and silicon substrate). In the latter chemical modification of the reactive groups of the pre-coated SAM has to be efficient enough such that a reasonable conversion can be obtained, with chemical specificity and lack of surface degradation. In this respect ‘click’ reactions have become attractive

• reported the formation of high quality vinyl-terminated SAMs generated from the vapour phase by adsorption of octadecyltrichlorosilanes onto silicon wafers [16]. With access to these SAMs it became an objective to explore functional group modification of the vinyl double bond. Carbon–carbon bond formation

• characterised by XPS, contact angle measurements and ellipsometry (see Supporting Information File 1). With XPS elements such as silicon, carbon and oxygen were expected in all cases [16]. In each case control reactions were also carried out on the C18-methyl (Me)-terminated SAMs, to ensure that only the vinyl

Solution processable diketopyrrolopyrrole (DPP) cored small molecules with BODIPY end groups as novel donors for organic solar cells

• Diego Cortizo-Lacalle,
• Calvyn T. Howells,
• Upendra K. Pandey,
• Joseph Cameron,
• Neil J. Findlay,
• Anto Regis Inigo,
• Tell Tuttle,
• Peter J. Skabara and
• Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2683–2695, doi:10.3762/bjoc.10.283

• Keithley 2400 source-measure unit and a Steuernagel AM 1.5 G solar simulator at 100 mW cm−2. The illumination intensity was verified and calibrated with an NREL calibrated mono-silicon detector with KG5 filter. External quantum efficiency (EQE) measurements were performed with an incident photon to charge

The effect of permodified cyclodextrins encapsulation on the photophysical properties of a polyfluorene with randomly distributed electron-donor and rotaxane electron-acceptor units

• Aurica Farcas,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert,
• Flavian Farcas,
• Iuliana Stoica and
• Anton Airinei

Beilstein J. Org. Chem. 2014, 10, 2145–2156, doi:10.3762/bjoc.10.222

• -shaped silicon cantilever with a resonance peak of 88 kHz. For image acquisition from different areas (squares with scanning length, Lsc, ranging from 1 μm to 20 μm), the Nova v.1.26.0.1443 for Solver software was used. The root mean square roughness (Sq) was calculated for all the investigated areas

Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing

• Bradley D. Rose,
• Peter J. Santa Maria,
• Aaron G. Fix,
• Chris L. Vonnegut,
• Lev N. Zakharov,
• Sean R. Parkin and
• Michael M. Haley

Beilstein J. Org. Chem. 2014, 10, 2122–2130, doi:10.3762/bjoc.10.219

• with symmetry (three mirror symmetry planes about the silicon), (2) bulky alkyl groups with symmetry, and (3) dimethyl-substituted possessing only one mirror plane of symmetry about the silicon. When looking further for trends, we compared two parameters to see if any of them ultimately yielded packing

Chiral phosphines in nucleophilic organocatalysis

• Yumei Xiao,
• Zhanhu Sun,
• Hongchao Guo and
• Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218