Synthesis of naturally-derived macromolecules through simplified electrochemically mediated ATRP

• Paweł Chmielarz,
• Tomasz Pacześniak,
• Katarzyna Rydel-Ciszek,
• Izabela Zaborniak,
• Paulina Biedka and
• Andrzej Sobkowiak

Beilstein J. Org. Chem. 2017, 13, 2466–2472, doi:10.3762/bjoc.13.243

• . As expected, addition of an alkyl halide initiator to a solution of CuIIBr2/TPMA during the voltammetric measurements causes a loss of reversibility and an increase of the cathodic current because of reduction of the regenerated CuIIBr2/TPMA via the catalytic electrochemical catalytic process (EC

Asymmetric synthesis of propargylamines as amino acid surrogates in peptidomimetics

• Matthias Wünsch,
• David Schröder,
• Tanja Fröhr,
• Lisa Teichmann,
• Sebastian Hedwig,
• Nils Janson,
• Clara Belu,
• Jasmin Simon,
• Shari Heidemeyer,
• Philipp Holtkamp,
• Jens Rudlof,
• Lennard Klemme,
• Alessa Hinzmann,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2017, 13, 2428–2441, doi:10.3762/bjoc.13.240

• -unsaturated imine are not reversible. Reversibility of the rearrangement would be fundamental for racemization of propargylamines, which is consequently improbable. However, even in the presence of strong bases like KOt-Bu or LDA, the propargylamide–allenylamide rearrangement could never be observed for

Selective enzymatic esterification of lignin model compounds in the ball mill

• Ulla Weißbach,
• Saumya Dabral,
• Laure Konnert,
• Carsten Bolm and
• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1788–1795, doi:10.3762/bjoc.13.173

• efficient for the enzyme-catalyzed selective esterification of the model compound erythro-1a, partly due to the non-reversibility of the reaction. However, isopropenyl esters of carboxylic acids are, in general, not readily available. Therefore, in order to find alternative acyl donors for the biocatalyst

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

• loss of cytopathogenicity. Interestingly, washing cells after mycolactone treatment restored cell growth, thus indicating at least a partial reversibility of the toxic effects. The structural proposal for mycolactone that was offered by Small and co-workers in the context of their original report on

From chemical metabolism to life: the origin of the genetic coding process

• Antoine Danchin

Beilstein J. Org. Chem. 2017, 13, 1119–1135, doi:10.3762/bjoc.13.111

Interactions between shape-persistent macromolecules as probed by AFM

• Johanna Blass,
• Jessica Brunke,
• Franziska Emmerich,
• Cédric Przybylski,
• Vasil M. Garamus,
• Artem Feoktystov,
• Roland Bennewitz,
• Gerhard Wenz and
• Marcel Albrecht

Beilstein J. Org. Chem. 2017, 13, 938–951, doi:10.3762/bjoc.13.95

• confirms the reversibility of the underlying interactions. It is difficult to estimate the number of supramolecular bonds contributing to pull-off forces of 1 nN in Figure 7. Based on the single bond rupture force one could assume contributions by 16 supramolecular bonds or even more since it is unlikely

Sulfamide chemistry applied to the functionalization of self-assembled monolayers on gold surfaces

• Loïc Pantaine,
• Vincent Humblot,
• Vincent Coeffard and
• Anne Vallée

Beilstein J. Org. Chem. 2017, 13, 648–658, doi:10.3762/bjoc.13.64

• contact angle (WCA) measurements, Fourier-transform infrared reflection absorption spectroscopy (IRRAS) and X-ray photoelectron spectroscopy (XPS). Keywords: gold surfaces; hydrolysis; IRRAS; reversibility; SAM; sulfamide; XPS; Introduction Self-assembled monolayers (SAMs) have raised considerable

• contact angle measurements to prove the reversibility of their process, a careful characterization of the surface has been carried out in this study [19]. Conclusion In conclusion, a new reaction on gold surfaces was reported based on sulfamide chemistry. In this work, two sulfamide species with different

Towards the development of continuous, organocatalytic, and stereoselective reactions in deep eutectic solvents

• Davide Brenna,
• Elisabetta Massolo,
• Alessandra Puglisi,
• Sergio Rossi,
• Giuseppe Celentano,
• Maurizio Benaglia and
• Vito Capriati

Beilstein J. Org. Chem. 2016, 12, 2620–2626, doi:10.3762/bjoc.12.258

• stereochemistry of the intermediate species involved in the catalytic cycle [41]. The equilibrating nature of the aldol reaction and the influence of such reversibility on its stereochemical outcome has recently been studied [42]. It has also been reported that the use of additives may have a dramatic influence

Diels–Alder reactions in confined spaces: the influence of catalyst structure and the nature of active sites for the retro-Diels–Alder reaction

• Ángel Cantín,
• M. Victoria Gomez and
• Antonio de la Hoz

Beilstein J. Org. Chem. 2016, 12, 2181–2188, doi:10.3762/bjoc.12.208

• reversibility of the reaction, homogeneous Lewis acids [1][2][3][4], solid acids [5][6] as catalyst, high pressures [6][7][8] and/or water as a solvent [9][10] have been reported. In particular, and among the most interesting environmental-friendly reactions, the cycloaddition reaction occurs with high

Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

• Dominik Urselmann,
• Konstantin Deilhof,
• Bernhard Mayer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2016, 12, 2055–2064, doi:10.3762/bjoc.12.194

• electronics [37][38][39][40]. In comparison to thiophene, phenothiazine, a tricyclic dibenzo-1,4-thiazine, possesses a significantly lower oxidation potential, similar to aniline. However, phenothiazine derivatives form stable deeply colored radical cations with perfect Nernstian reversibility [41][42][43][44

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

• Lucie Brulíková,
• Aidan Harrison,
• Marvin J. Miller and
• Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

• and natural products as well as for the mild functionalization and derivatization of diene-containing natural products [1][2][3][4][5][6][7][8][9][10]. The reversibility of this reaction plays a considerable role in both the observed regio- and stereocontrol of the nitroso Diels–Alder reaction

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

The role of alkyl substituents in deazaadenine-based diarylethene photoswitches

• Christopher Sarter,
• Michael Heimes and
• Andres Jäschke

Beilstein J. Org. Chem. 2016, 12, 1103–1110, doi:10.3762/bjoc.12.106

• hybridization upon switching [43][44]. This new class of diarylethenes showed promising photophysical and photochemical properties, such as the location of the photostationary states, reversibility of switching, thermal stability, and fatigue resistance. In 2013 we developed a 2nd generation of diarylethene

• photochemical properties, in particular their photochromicity, switching kinetics and reversibility, fatigue resistance, and thermostability, were investigated. The main text shows only the analytical data for new pyridyl switch 1b in comparison to the previously published and well-studied switch 2b [43]; all

• the differences between the one- and two-methyl switches are not due to solvent effects. This latter observation already indicated poor reversibility and fatigue resistance for the one-methyl switches. We therefore undertook absorption measurements over multiple cycles of ring closure by UV and ring

Supramolecular structures based on regioisomers of cinnamyl-α-cyclodextrins – new media for capillary separation techniques

• Gabor Benkovics,
• Ondrej Hodek,
• Martina Havlikova,
• Zuzana Bosakova,
• Pavel Coufal,
• Milo Malanga,
• Eva Fenyvesi,
• Andras Darcsi,
• Szabolcs Beni and
• Jindrich Jindrich

Beilstein J. Org. Chem. 2016, 12, 97–109, doi:10.3762/bjoc.12.11

• intermolecular bonding, the formation and decomposition of the SP is at thermodynamic equilibrium, which means that the polymer growth or the destruction of the polymer chain can be adjusted by external stimuli. This reversibility makes SPs promising functional materials and gives them the potential to be easily

Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation

• Jie Wang,
• Zhiqiang Qiu,
• Yiming Wang,
• Li Li,
• Xuhong Guo,
• Duc-Truc Pham,
• Stephen F. Lincoln and
• Robert K. Prud’homme

Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7

• reversibility of the solution/hydrogel transition is observed in rheological experiments. In vitro tests show that the PEG-b-PAA/cisplatin hydrogel has a sustained cisplatin release over three days and that it has a high cytotoxity towards human bladder carcinoma EJ cells. 5 Responsive smart materials

Assembly of synthetic Aβ miniamyloids on polyol templates

• Sebastian Nils Fischer and
• Armin Geyer

Beilstein J. Org. Chem. 2015, 11, 2646–2653, doi:10.3762/bjoc.11.284

• chemistry is the self-correcting reversibility if individual peptides which are bound in the wrong orientation resulting in a strong preference for defined ring sizes [18] or oligomerization degrees [19]. The idea appears especially attractive for the assembly of peptides with high aggregation tendencies

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

• steric repulsion is important for achieving SNP stability. SNPs of controlled particle size and good stability (up to seven days) were prepared by fine-tuning the ratio of multivalent and monovalent interactions. Finally, reversibility of the SNPs was confirmed by oxidizing the Fc guest moieties in the

• controlled by the stoichiometry of the multivalent guest and the monovalent stabilizer. Finally, the reversibility of the SNPs is assessed by studying the influence of oxidation of the Fc moieties. Results and Discussion Characterization of building blocks The positively charged host CD-PEI was synthesized

Photoinduced 1,2,3,4-tetrahydropyridine ring conversions

• Baiba Turovska,
• Henning Lund,
• Viesturs Lūsis,
• Anna Lielpētere,
• Edvards Liepiņš,
• Sergejs Beljakovs,
• Inguna Goba and
• Jānis Stradiņš

Beilstein J. Org. Chem. 2015, 11, 2166–2170, doi:10.3762/bjoc.11.234

• traces of dioxygen was observed. In deaereated aprotic solvents 1 undergoes a reversible one-electron single-step oxidation [16] (+1.00 V in MeCN or +1.25 V in CH2Cl2) while the reversibility of the anodic process disappears immediately after the argon flow through/over the solution has been stopped

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

• , with respect to the level of oxidation that is achieved per repeating unit, the excellent electrochemical reversibility observed, and the modest potential window in which the highly doped state is attained. Even for a stable doped system, for example a PEDOT sample heavily doped with

Interactions between tetrathiafulvalene units in dimeric structures – the influence of cyclic cores

• Huixin Jiang,
• Virginia Mazzanti,
• Christian R. Parker,
• Søren Lindbæk Broman,
• Jens Heide Wallberg,
• Karol Lušpai,
• Adam Brincko,
• Henrik G. Kjaergaard,
• Anders Kadziola,
• Peter Rapta,
• Ole Hammerich and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2015, 11, 930–948, doi:10.3762/bjoc.11.104

• −1 used for these studies, the reversibility remains unchanged confirming the high stability of the formed radical cation and dication states within each TTF redox site (in further text defined as “polaron” and “bipolaron” states, respectively; see Scheme 4). The small peak separation, ΔE, between

Impact of multivalent charge presentation on peptide–nanoparticle aggregation

• Daniel Schöne,
• Boris Schade,
• Christoph Böttcher and
• Beate Koksch

Beilstein J. Org. Chem. 2015, 11, 792–803, doi:10.3762/bjoc.11.89

• assembly [9]. Peptide-based nanoparticle aggregation was demonstrated first by Woolfson and coworkers by means of coiled-coil peptides that were immobilized on the nanoparticle surface [26]. Reversibility of the assembly formation, a key feature of a switchable system, has thus far been explored only for a

• few nanoparticle systems by means of temperature [19]; most of the assemblies are irreversibly formed [9], or reversibility is only achieved by adding, for example, oxidizing reagents [27]. Continuous switch behaviour between aggregated and non-aggregated nanoparticles is not obtained as the formation

Orthogonal dual-modification of proteins for the engineering of multivalent protein scaffolds

• Michaela Mühlberg,
• Michael G. Hoesl,
• Christian Kuehne,
• Jens Dernedde,
• Nediljko Budisa and
• Christian P. R. Hackenberger

Beilstein J. Org. Chem. 2015, 11, 784–791, doi:10.3762/bjoc.11.88

• cysteine has some drawbacks including the high tendency for disulfide bond formation or cross reaction with other cysteine residues, reaction reversibility, and occasionally side-reactions with basic side chains, e.g., lysines [33]. Specifically, in the current paper we use in the current paper the oxime

On the strong difference in reactivity of acyclic and cyclic diazodiketones with thioketones: experimental results and quantum-chemical interpretation

• Andrey S. Mereshchenko,
• Alexey V. Ivanov,
• Viktor I. Baranovskii,
• Grzegorz Mloston,
• Ludmila L. Rodina and
• Valerij A. Nikolaev

Beilstein J. Org. Chem. 2015, 11, 504–513, doi:10.3762/bjoc.11.57

• alkenes. In the case of the C=S ylides bearing two alkoxycarbonyl groups, the latter pathway clearly dominates. The reversibility of the 1,5-electrocyclization of the transient C=S ylide, generated from diazomalonate 1d and thione 2b, is attributed to a relatively low activation barrier (ΔG# = 23.8

Azirinium ylides from α-diazoketones and 2H-azirines on the route to 2H-1,4-oxazines: three-membered ring opening vs 1,5-cyclization

• Nikolai V. Rostovskii,
• Mikhail S. Novikov,
• Alexander F. Khlebnikov,
• Galina L. Starova and
• Margarita S. Avdontseva

Beilstein J. Org. Chem. 2015, 11, 302–312, doi:10.3762/bjoc.11.35

• form in this reaction, and, moreover, its formation from ylide 9j is kinetically preferred over the formation of azadiene 3j. However, in view of the reversibility of the 1,5-cyclization 9j →10j and in the absence of an active trap for azirenooxazole 10j in the reaction mixture, it isomerizes via ylide

Anionic sigmatropic-electrocyclic-Chugaev cascades: accessing 12-aryl-5-(methylthiocarbonylthio)tetracenes and a related anthra[2,3-b]thiophene

• Laurence Burroughs,
• John Ritchie,
• Mkhethwa Ngwenya,
• Dilfaraz Khan,
• William Lewis and
• Simon Woodward

Beilstein J. Org. Chem. 2015, 11, 273–279, doi:10.3762/bjoc.11.31

• rearrangement of 1a [14] or by SN2’ carbonate displacement in 1b by Pd0(PPh3)2 in Liu’s case [16]. To circumvent reversibility of these pericyclic annulation strategies Lin relied on PhSOH elimination while Liu relied on ubiquitous palladium β-hydride steps leading to tetracenes 3 and 4. We are interested in