Enantioselective carbenoid insertion into C(sp³)–H bonds

• J. V. Santiago and
• A. H. L. Machado

Beilstein J. Org. Chem. 2016, 12, 882–902, doi:10.3762/bjoc.12.87

• with the opposite effect. Due to these observations, a carbenoid intermediate can be divided in three different classes based on the electronic nature of the chemical groups attached to its structure: acceptor, donor/acceptor and acceptor/acceptor (Figure 2) [2]. The modification of the substituents on

• the carbenoid intermediate can change its reactivity and hence the selectivity of the carbenoid reaction. The most commonly used diazo compounds rely on the formation of a donor/acceptor carbenoid intermediate type. The EWG increases the electrophilicity and reactivity of the donor/acceptor carbenoid

• )–H when X = Ph or H. The first reason concerns the relative stability of the carbenoids 38-Ph and 38-H. The first one, prepared from the donor/acceptor diazo compound 36-Ph, is 10.9 kcal more stable than the carbenoid 38-H obtained from the acceptor diazo compound 36-H. This observation was

Synthesis and fluorosolvatochromism of 3-arylnaphtho[1,2-b]quinolizinium derivatives

• Phil M. Pithan,
• David Decker,
• Manlio Sutero Sardo,
• Giampietro Viola and
• Heiko Ihmels

Beilstein J. Org. Chem. 2016, 12, 854–862, doi:10.3762/bjoc.12.84

• emission lifetime. Notably, a considerable number of solvatochromic molecules is based on charge-transfer (CT) processes in the excited state resulting from a pronounced donor–acceptor interplay within the fluorophore [8]. Thus, upon excitation of such compounds, a CT – or in charged species a charge shift

• ][12]. Along these lines, we established the annelated quinolizinium ion as a versatile platform for the investigation of cationic chemosensors, especially when the chromophore is incorporated within a donor–acceptor system [13]. In particular, we observed that biaryl-type quinolizinium derivatives

• characteristic of donor–acceptor dyes, namely a cumulative red shift of the emission maximum with increasing solvent polarity, along with a broad, unstructured band structure [1][2]. To assess the effect of the solvent on the emission of compound 6e several different solvents were employed. Unfortunately, many

Scope and mechanism of the highly stereoselective metal-mediated domino aldol reactions of enolates with aldehydes

• M. Emin Cinar,
• Bernward Engelen,
• Martin Panthöfer,
• Hans-Jörg Deiseroth,
• Jens Schlirf and
• Michael Schmittel

Beilstein J. Org. Chem. 2016, 12, 813–824, doi:10.3762/bjoc.12.80

• a decrease of the yield compared with 5a (Scheme 5, Table 7). The best yields were obtained within a series in the case of ketone and aldehyde possessing a donor–acceptor situation. Domino aldol reaction by using a CYTOS™ microreactor Using the CYTOS™ microreactor, a continuous reactor, the

Is conformation a fundamental descriptor in QSAR? A case for halogenated anesthetics

• Maria C. Guimarães,
• Mariene H. Duarte,
• Josué M. Silla and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2016, 12, 760–768, doi:10.3762/bjoc.12.76

• interactions govern the conformational equilibrium in a biological-free environment. Indeed, Lesarri et al. [15] pointed out that anomeric effects owing to donor–acceptor (LP → σ*) interactions are responsible for the conformational preference of isoflurane. Despite the contribution from specific

Direct estimate of the internal π-donation to the carbene centre within N-heterocyclic carbenes and related molecules

• Diego M. Andrada,
• Nicole Holzmann,
• Thomas Hamadi and
• Gernot Frenking

Beilstein J. Org. Chem. 2015, 11, 2727–2736, doi:10.3762/bjoc.11.294

• the zeroth-order regular approximation (ZORA) [86]. The nature of the stationary points on the potential energy surface was determined by calculating the vibrational frequencies at BP86/TZ2P+. These calculations were performed with the program package ADF.2013 [87]. The bonding situation of the donor

• –acceptor bonds was investigated by an energy decomposition analysis (EDA) which was developed by Morokuma [88] and by Ziegler and Rauk [89][90]. The bonding analysis focuses on the instantaneous interaction energy ∆Eint of a bond A–B between two fragments A and B in the particular electronic reference

Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• secondary structures from aromatic backbones driven by different noncovalent forces (including hydrogen bonding, donor–acceptor, solvophobicity, and dimerization of conjugated radical cations) and solution-phase supramolecular organic frameworks driven by hydrophobically initiated aromatic stacking in the

• cavity of cucurbit[8]uril (CB[8]) are highlighted. Keywords: donor–acceptor interaction; foldamer; hydrogen bond; radical cation dimerization; supramolecular organic framework; Review Childhood and growing up I was born on July 23rd, 1966 in the small, remote village of Fang-Liu (a combination of two

• the University of South Denmark: donor–acceptor interaction-driven catenanes From October 1994 to December 1995, I performed postdoctoral research with Professor Jan Becher at Odense University (currently University of South Denmark) in Denmark. Through his research career, Professor Becher studied

Synthesis of quinoline-3-carboxylates by a Rh(II)-catalyzed cyclopropanation-ring expansion reaction of indoles with halodiazoacetates

• Magnus Mortén,
• Martin Hennum and
• Tore Bonge-Hansen

Beilstein J. Org. Chem. 2015, 11, 1944–1949, doi:10.3762/bjoc.11.210

• carbenoids: acceptor-acceptor [9][10][11], mono-acceptor [12] and donor-acceptor [13][14][15][16], and all the carbenoids react preferentially at the electron rich C2–C3 double bond. The catalysts used for the generation of the carbenoids are typically salts of Cu [9][11][13], Rh [10][12][16], Fe [14] and Ru

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

• from those in solution (−4.95/−3.55 eV), which suggested significant donor–acceptor interactions in the solid phase between the DPP and TTF units. OFET device fabrication employing polymer 48 exhibited p-type semiconductor behaviour, with the best performance from devices using the bottom contact top

• dithienyl-thieno-TTF unit and the localised nature of the LUMO led to donor–acceptor interactions in the solid phase, making it impossible for efficient overlap between LUMOs, which would normally be required for an efficient n-type semiconductor. BHJSCs were fabricated from 48 as the electron donor and

• performance is modest compared to that of similar devices fabricated using donor–acceptor block copolymers [88][89][90]. Nevertheless, the value of the PCE (0.31%) is higher than one would expect from a SMOSC fabricated from polymer 48 as a semiconductor, since it has no obvious donor–acceptor phase

Towards inhibitors of glycosyltransferases: A novel approach to the synthesis of 3-acetamido-3-deoxy-D-psicofuranose derivatives

• Maroš Bella,
• Miroslav Koóš and
• Chun-Hung Lin

Beilstein J. Org. Chem. 2015, 11, 1547–1552, doi:10.3762/bjoc.11.170

• complexity of the GnTs catalytic mechanism. The main reasons originating from the complex character of the catalytic mechanism which complicate the search for GnTs inhibitors are a) participation of four components in the transition state (sugar donor, acceptor, nucleotide and metal co-factor), b) weak

Advances in the synthesis of functionalised pyrrolotetrathiafulvalenes

• Luke J. O’Driscoll,
• Sissel S. Andersen,
• Marta V. Solano,
• Dan Bendixen,
• Morten Jensen,
• Troels Duedal,
• Jess Lycoops,
• Cornelia van der Pol,
• Rebecca E. Sørensen,
• Karina R. Larsen,
• Kenneth Myntman,
• Christian Henriksen,
• Stinne W. Hansen and
• Jan O. Jeppesen

Beilstein J. Org. Chem. 2015, 11, 1112–1122, doi:10.3762/bjoc.11.125

• served as intermediates and model systems in the synthesis of, for example, donor–acceptor systems, chemosensors and materials with molecular electronics applications [44][56]. The N-tosyl protecting group of precursor MPTTFs (4c, 4d, 4f and 4g) must first be removed. This can be achieved in excellent

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

Donor–acceptor type co-crystals of arylthio-substituted tetrathiafulvalenes and fullerenes

• Xiaofeng Lu,
• Jibin Sun,
• Shangxi Zhang,
• Longfei Ma,
• Lei Liu,
• Hui Qi,
• Yongliang Shao and
• Xiangfeng Shao

Beilstein J. Org. Chem. 2015, 11, 1043–1051, doi:10.3762/bjoc.11.117

• Xiaofeng Lu Jibin Sun Shangxi Zhang Longfei Ma Lei Liu Hui Qi Yongliang Shao Xiangfeng Shao State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Tianshui Southern Road 222, Lanzhou 730000, Gansu Province, P. R. China 10.3762/bjoc.11.117 Abstract A series of donor–acceptor type

• axes. In the type II co-crystals, one fullerene molecule has the donor–acceptor mode similar to that in type I, whereas the other fullerene molecule is substantially surrounded by the aryl groups on Ar-S-TTF molecules and the solvent molecules. Keywords: arylthio-substituted tetrathiafulvalene; co

• -crystal; donor–acceptor system; fullerene; Introduction Tetrathiafulvalene (TTF) [1][2][3] and its derivatives have attracted significant interest for decades. This is because this unique heterocycle system has provided most of the organic conductors possessing diverse electronic ground states [4][5][6

Glycoluril–tetrathiafulvalene molecular clips: on the influence of electronic and spatial properties for binding neutral accepting guests

• Yoann Cotelle,
• Marie Hardouin-Lerouge,
• Stéphanie Legoupy,
• Olivier Alévêque,
• Eric Levillain and
• Piétrick Hudhomme

Beilstein J. Org. Chem. 2015, 11, 1023–1036, doi:10.3762/bjoc.11.115

• control binding interaction towards a strong electron acceptor such as tetrafluorotetracyanoquinodimethane (F4-TCNQ) or a weaker electron acceptor such as 1,3-dinitrobenzene (m-DNB). Keywords: donor–acceptor interactions; glycoluril; molecular clips; supramolecular chemistry; tetrathiafulvalene

• through an induced-fit mechanism with a recognition process on the basis of the size rather than the acceptor strength. We can suppose that the presence of stronger π-donor TTF sidewalls in clip 3 favorize donor–acceptor interactions and consequently the binding properties towards m-DNB. We have also

Trifluoromethyl-substituted tetrathiafulvalenes

• Olivier Jeannin,
• Frédéric Barrière and
• Marc Fourmigué

Beilstein J. Org. Chem. 2015, 11, 647–658, doi:10.3762/bjoc.11.73

• -transfer salt. Note also that this donor–acceptor interaction leads to a strong planarization of the dithiole rings of 1c in (1c)2(TCNQ) with folding angles along the S…S hinge of the two dithiole rings amounting now to 10.13(17)° and 1.90(16)° on the dithioethylene and CF3 sides, respectively. By

Functionalized branched EDOT-terthiophene copolymer films by electropolymerization and post-polymerization “click”-reactions

• Miriam Goll,
• Adrian Ruff,
• Erna Muks,
• Felix Goerigk,
• Beatrice Omiecienski,
• Ines Ruff,
• Rafael C. González-Cano,
• Juan T. Lopez Navarrete,
• M. Carmen Ruiz Delgado and
• Sabine Ludwigs

Beilstein J. Org. Chem. 2015, 11, 335–347, doi:10.3762/bjoc.11.39

• widely used approach is the introduction of different co-monomers to build up copolymers, e.g., new donor–acceptor low band gap copolymers [12][13][14]. Among synthetic approaches electropolymerization has gained particular attention, because it allows easy tuning of polymer film properties by

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

• common technique to optimise morphology is to vary the donor/acceptor ratio. A screening of various donor/acceptor ratios revealed that the most promising performance was evident with the ratio 1:3 (Figures S15 and S16, Supporting Information File 1). As the concentration of the acceptor is increased

• difference in Voc between 9:PC71BM and 10:PC71BM of 0.71 and 0.53 V, respectively. A favourable dark current is observed with 9:PC71BM when compared with 10:PC71BM (Figure 10) for the same donor acceptor concentration ratio. There are several possible reasons why we observe a lower Voc with 10:PC71BM than 9

Galactan synthesis in a single step via oligomerization of monosaccharides

• Marius Dräger and
• Amit Basu

Beilstein J. Org. Chem. 2014, 10, 2658–2663, doi:10.3762/bjoc.10.279

• that oligogalactans as long as pentamers can be generated in a single reaction by the activation of a bifunctional galactosyl donor/acceptor in the presence of an initiating alcohol. While isolated yields of the tri-, tetra-, and pentasaccharides are modest, the obtained yields of 19%, 10%, and 4

Host–guest-driven color change in water: influence of cyclodextrin on the structure of a copper complex of poly((4-hydroxy-3-(pyridin-3-yldiazenyl)phenethyl)methacrylamide-co-dimethylacrylamide)

• Nils Retzmann,
• Gero Maatz and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 2480–2483, doi:10.3762/bjoc.10.259

• Figure 1. The addition of CuSO4 to polymer 7 in a water/methanol mixture caused a color change from orange to red, which could be reversed by subsequent addition of γ-CD (Figure 1). Thus, we can anticipate a donor–acceptor-type bonding of the electron-rich azo dye with copper ions, that can be displaced

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

• conjugated hydrocarbons; Introduction Polycyclic conjugated hydrocarbons (PCHs) have been studied extensively due to the wide variety of physical properties that can be accessed by appropriate manipulation or “tuning” of a molecular scaffold (e.g., installation of donor/acceptor groups, inclusion of

OligArch: A software tool to allow artificially expanded genetic information systems (AEGIS) to guide the autonomous self-assembly of long DNA constructs from multiple DNA single strands

• Kevin M. Bradley and
• Steven A. Benner

Beilstein J. Org. Chem. 2014, 10, 1826–1833, doi:10.3762/bjoc.10.192

• aggregation/folding motifs. With strength comparable to the G:C pair, AEGIS components form S:B, Z:P, V:J, and K:X pairs. (top) The conversion of S:B pairs to T:A pairs involves tautomerization of B to give its minor enol form, which present a hydrogen bond Donor–Acceptor–Donor pattern complementary to T. If

Synthesis of new, highly luminescent bis(2,2’-bithiophen-5-yl) substituted 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole

• Anastasia S. Kostyuchenko,
• Vyacheslav L.Yurpalov,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2014, 10, 1596–1602, doi:10.3762/bjoc.10.165

• synthetic approach towards the preparation of functionalised, soluble, donor–acceptor (DA) alkylbithiophene derivatives of oxadiazole, thiadiazole and triazole is reported. Taking advantage of the Fiesselmann reaction, reactive bithiophene synthons having alkyl or alkoxy substituents at designated positions

• functionalised oligothiophenes, coupled to other heteroaromatic cores. Keywords: bithiophene; donor–acceptor; luminescence; 1,3,4-oxadiazole; 1,3,4-thiadiazole; 4H-1,2,4-triazole; Introduction In the past two decades oligo- and polythiophenes gained a significant research interest due to their wide application

• the impaired conjugation of the triazole moiety with the bithiophene arms. Comparing the obtained results with those reported for similar donor–acceptor–donor compounds, we can see that both the number of donor groups and the chemical nature of the central electron accepting ring exert strong

Influence of perylenediimide–pyrene supramolecular interactions on the stability of DNA-based hybrids: Importance of electrostatic complementarity

• Christian B. Winiger,
• Simon M. Langenegger,
• Oleg Khorev and
• Robert Häner

Beilstein J. Org. Chem. 2014, 10, 1589–1595, doi:10.3762/bjoc.10.164

• linked by negatively charged phosphodiester groups [29]. The importance of aromatic and hydrophobic factors for duplex stability was demonstrated by replacing the natural nucleobases by size expanded analogs [30][31][32][33][34][35]. A classic example of polymeric donor–acceptor complexes are the

• aedamers (aromatic electron donor acceptor oligomers) pioneered by Iverson and coworkers [18][36][37]. They consist of face-to-face stacked electron-rich naphthalene and electron-poor naphthalenediimide (NDI) chromophores and belong to the broader area of foldamers [38]. DNA has been described as a

Organic synthesis using photoredox catalysis

• Axel G. Griesbeck

Beilstein J. Org. Chem. 2014, 10, 1097–1098, doi:10.3762/bjoc.10.107

• -coated semiconductor nanoparticles. On the substrate side, the focus is on redox-active donor/acceptor molecules, which range from all kind of aromatic, olefinic and carbonyl-type electron acceptor compounds to heteroatom-linked electron donors. The relevance of carbon–carbon bond formation for organic

The Ugi four-component reaction as a concise modular synthetic tool for photo-induced electron transfer donor-anthraquinone dyads

• Sarah Bay,
• Gamall Makhloufi,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 1006–1016, doi:10.3762/bjoc.10.100

• . These novel donor–acceptor dyads are electronically decoupled in the electronic ground state according to UV–vis spectroscopy and cyclic voltammetry. However, in the excited state the inherent donor luminescence is efficiently quenched. Previously performed femtosecond spectroscopic measurements account

• these novel donor–acceptor dyads. In addition, the X-ray structure of a phenothiazinyl–anthraquinone dyad supports short donor–acceptor distances by an intramolecular π-stacking conformation, an important assumption also implied in the calculations of the Gibbs energies according to the Weller

• anthraquinone-substituted aldehyde together with acetic acid and tert-butyl isocyanide for rapidly assembling a donor–acceptor conjugate 1 displaying a photo-induced electron transfer leading to a charge-separated state with a lifetime of >2 ns (Figure 1), as elucidated by femtosecond transient absorption

Conformational analysis of 2,2-difluoroethylamine hydrochloride: double gauche effect

• Josué M. Silla,
• Claudimar J. Duarte,
• Rodrigo A. Cormanich,
• Roberto Rittner and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2014, 10, 877–882, doi:10.3762/bjoc.10.84

• perturbation analysis of donor-acceptor interactions in the natural bond orbitals (NBOs) framework shows that the global minimum of 1 is more stabilized by hyperconjugation than the other conformers (both in the gas phase and implicit water), despite being significantly destabilized by Lewis-type interactions