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

• small organic molecules. A direct alkaline methanol FC was already tested in 1965 oxidizing methanol over a Pt catalyst in highly alkaline medium [8]. Alcohols such as ethanol and glycerol are valuable and non-toxic substrates for DAAFCs, too. However, the higher chemical complexity of the alcohols

Fluorocyclisation via I(I)/I(III) catalysis: a concise route to fluorinated oxazolines

• Felix Scheidt,
• Christian Thiehoff,
• Gülay Yilmaz,
• Stephanie Meyer,
• Constantin G. Daniliuc,
• Gerald Kehr and
• Ryan Gilmour

Beilstein J. Org. Chem. 2018, 14, 1021–1027, doi:10.3762/bjoc.14.88

• the generation of structural complexity [13][14][15][16][17][18][19][20][21][22][23][24]. Motivated by the noticeable absence of mild, catalysis-based strategies to generate the vicinal difluoroethylene motif directly from simple alkenes [25][26][27], we recently exploited I(I)/I(III) catalysis to

On the design principles of peptide–drug conjugates for targeted drug delivery to the malignant tumor site

• Eirinaios I. Vrettos,
• Gábor Mező and
• Andreas G. Tzakos

Beilstein J. Org. Chem. 2018, 14, 930–954, doi:10.3762/bjoc.14.80

• indicate that cancer is not retreating but is creeping up, tending to become the leading cause of mortality. Thus, it can be concluded that the current therapeutic formulations utilized in oncology are not adequately effective against the complexity of cancer, mostly due to the associated collateral

Crystal structure of the inclusion complex of cholesterol in β-cyclodextrin and molecular dynamics studies

• Elias Christoforides,
• Andreas Papaioannou and
• Kostas Bethanis

Beilstein J. Org. Chem. 2018, 14, 838–848, doi:10.3762/bjoc.14.69

• was 0.664. The structure has been solved by intrinsic phasing method with SHELXT [39] and refined by full-matrix least squares against F2 using SHELXL-2014/7 [40] through the SHELXLE GUI [41] giving a final R1 index of ≈0.10. Due to the structural complexity of the inclusion compound, soft restraints

Phosphodiester models for cleavage of nucleic acids

• Satu Mikkola,
• Tuomas Lönnberg and
• Harri Lönnberg

Beilstein J. Org. Chem. 2018, 14, 803–837, doi:10.3762/bjoc.14.68

Chlorination of phenylallene derivatives with 1-chloro-1,2-benziodoxol-3-one: synthesis of vicinal-dichlorides and chlorodienes

• Zhensheng Zhao and
• Graham K. Murphy

Beilstein J. Org. Chem. 2018, 14, 796–802, doi:10.3762/bjoc.14.67

• -chlorostyrene groups, installing them in close proximity (as shown in 3) provides two handles for rapidly achieving high-density molecular complexity. Thus, the development of strategies for their synthesis is an important endeavour. We envisioned accomplishing this by developing a chemo- and regioselective

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• performing catalytic reactions with high enantioselectivity and efficiency [13][14]. As a result, a wide range of chiral catalysts have been established [15][16]. Chiral catalysts are, however, not only incompatible with aqueous solutions, but also expensive due to the structural complexity of the ligands

Latest development in the synthesis of ursodeoxycholic acid (UDCA): a critical review

• Fabio Tonin and
• Isabel W. C. E. Arends

Beilstein J. Org. Chem. 2018, 14, 470–483, doi:10.3762/bjoc.14.33

• complexity and multitude of steps involved of the synthetic process. For these reasons, several studies have been performed towards the development of microbial transformations or chemoenzymatic procedures for the synthesis of UDCA starting from CA or chenodeoxycholic acid (CDCA). This promising approach led

• ) in the treatment against biliary calculus, since it possesses high efficacy and total absence of side effects [11]. UDCA is commonly produced by transformation of cholic acid (CA), which is the most abundant and least expensive bile acid available. Because of the molecular complexity of bile acids

Fluorescent nucleobase analogues for base–base FRET in nucleic acids: synthesis, photophysics and applications

• Mattias Bood,
• Sangamesh Sarangamath,
• Moa S. Wranne,
• Morten Grøtli and
• L. Marcus Wilhelmsson

Beilstein J. Org. Chem. 2018, 14, 114–129, doi:10.3762/bjoc.14.7

• protection groups is paramount as an extensive use adds additional steps as well as complexity to the synthesis. The design and synthesis of fluorescent nucleobase analogues (FBAs) add on additional challenges such as obtaining features that introduce useful photophysical properties, for example, extended

Polarization spectroscopy methods in the determination of interactions of small molecules with nucleic acids – tutorial

• Tamara Šmidlehner,
• Ivo Piantanida and
• Gennaro Pescitelli

Beilstein J. Org. Chem. 2018, 14, 84–105, doi:10.3762/bjoc.14.5

Consecutive hydrazino-Ugi-azide reactions: synthesis of acylhydrazines bearing 1,5-disubstituted tetrazoles

• Angélica de Fátima S. Barreto,
• Veronica Alves dos Santos and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2017, 13, 2596–2602, doi:10.3762/bjoc.13.256

• ) allow the construction of relatively complex molecules through a one-pot synthesis. The combination of IMCRs in a consecutive or sequential fashion further extends the complexity of the molecules obtained. Herein, we report the efficient application of this approach to the synthesis of acylhydrazines

Influence of the milling parameters on the nucleophilic substitution reaction of activated β-cyclodextrins

• László Jicsinszky,
• Kata Tuza,
• Giancarlo Cravotto,
• Andrea Porcheddu,
• Francesco Delogu and
• Evelina Colacino

Beilstein J. Org. Chem. 2017, 13, 1893–1899, doi:10.3762/bjoc.13.184

• differences are also elements of complexity. The mechanical processing of CDs in the absence of solvent therefore promises to simplify the work-up and allows the almost complete utilization of the CD key-intermediate [13], in comparison with the classic method [6]. Moreover, the absence of a solvent, high

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

• the ball mill (Scheme 1c). The results of this proof-of-concept study are presented here. Results and Discussion Due to the high complexity of the lignin structure, which often presents a challenge during the product composition analysis, the use of lignin model compounds to monitor preliminary

Theoretical simulation of the infrared signature of mechanically stressed polymer solids

• Matthew S. Sammon,
• Milan Ončák and
• Martin K. Beyer

Beilstein J. Org. Chem. 2017, 13, 1710–1716, doi:10.3762/bjoc.13.165

• result from numerous overlapping C–H and backbone vibrations. Due to their complexity, as described in detail before for polypropylene [30], as well as the lower intensity compared to vibrations from strongly IR active functional groups, they do not seem to be a valuable reference for force-dependent

A recursive microfluidic platform to explore the emergence of chemical evolution

• David Doran,
• Marc Rodriguez-Garcia,
• Rebecca Turk-MacLeod,
• Geoffrey J. T. Cooper and
• Leroy Cronin

Beilstein J. Org. Chem. 2017, 13, 1702–1709, doi:10.3762/bjoc.13.164

• . Therefore, our group is also developing a metric for evaluating the complexity of chemical species produced in artificially evolving systems. This complexity measurement will be thresholded using existing biological systems and by comparison with the starting inputs into our evolutionary platform. An

• artificial living system would be capable not only of evolution, but also of producing species with a greater complexity than would be expected to arise from any non-biological system [12]. Thus, the transition from an evolving but non-living chemical system to an evolving living system will be marked by

• production of species of comparable complexity to those found exclusively in biology, as depicted in Figure 1. Droplet compartmentalisation In our previous work, we described the assembly of a custom-made 3D printed robotic platform that uses artificial evolution to select for desired behaviours in chemical

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

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• matter remains an intensely challenging scientific problem. The complexity of the biochemical machinery of cells with its exquisite intricacies hints at cells being the product of a long evolutionary process. Research on the emergence of life has long been focusing on specific, well-defined problems

• ], the complexity of de novo RNA synthesis and its functional interconnection with other biopolymers in the cellular context question its early, single-handed role. The polymerization of short RNA chains and peptides has been investigated within aqueous vesicle lumens as well as water/oil emulsions, and

• using a mediator, rhenium bipyridine (a molecule similar to the ruthenium complex in Figure 2B). A concomitant development (complexity increase) of membranes and light/energy harvesting/conversion systems can thus be seen as a prerequisite in the evolution of the ancestral bioenergetics en route to the

Grip on complexity in chemical reaction networks

• Albert S. Y. Wong and
• Wilhelm T. S. Huck

Beilstein J. Org. Chem. 2017, 13, 1486–1497, doi:10.3762/bjoc.13.147

• Albert S. Y. Wong Wilhelm T. S. Huck Institute for Molecular Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands 10.3762/bjoc.13.147 Abstract A new discipline of “systems chemistry” is emerging, which aims to capture the complexity observed in natural

• systems within a synthetic chemical framework. Living systems rely on complex networks of chemical reactions to control the concentration of molecules in space and time. Despite the enormous complexity in biological networks, it is possible to identify network motifs that lead to functional outputs such

• chemical entities on the properties of the network as a whole. Ultimately, this approach should allow us to not only understand such complex networks but also to guide and control their behavior. Keywords: chemical reaction network; complexity; dissipative systems; network motifs; out-of-equilibrium

Framing major prebiotic transitions as stages of protocell development: three challenges for origins-of-life research

• Ben Shirt-Ediss,
• Sara Murillo-Sánchez and
• Kepa Ruiz-Mirazo

Beilstein J. Org. Chem. 2017, 13, 1388–1395, doi:10.3762/bjoc.13.135

• in finding a plausible sequence of transitions from abiotic physical and chemical processes towards this level of molecular and organisational complexity, unparalleled by any other phenomena that we observe in the natural world. Therefore, facing this challenge always involves making a strong set of

• compartmentalised chemistries run by poly-nucleotides (e.g., the ‘ribocell’ model), protocell systems with molecular components of much lower molecular complexity should be investigated as units of pre-Darwinian evolution. The overarching question then becomes: how can far-from-equilibrium chemical assemblies that

• ways to pay the ‘cost of irreversibility’ as Pascal and colleagues [63] express it). But in order to understand what might be underlying or ‘driving’ those transitions towards higher complexity levels (i.e., the blue arrows signalling the ‘MT’s in Figure 1), one should beware of reductionist or

Detection of therapeutic radiation in three-dimensions

• John A. Adamovics

Beilstein J. Org. Chem. 2017, 13, 1325–1331, doi:10.3762/bjoc.13.129

• radioactive source (brachytherapy), or a liquid radiation source placed near or inside the cancerous area. In the last decade the sophistication and complexity of radiation therapy treatment has increased dramatically. Advances have been so swift that an imbalance has arisen with verification technologies

Biomimetic molecular design tools that learn, evolve, and adapt

• David A Winkler

Beilstein J. Org. Chem. 2017, 13, 1288–1302, doi:10.3762/bjoc.13.125

• ]. Intensive experimental effort has been applied to the deliberate reengineering of biosynthetic pathways for natural product synthesis which, when combined with directed evolution, can generate libraries of potentially bioactive organic molecules with significant diversity and high chemical complexity [4

• entirely eliminated by the additional of an additional operation called regularization, essentially applying a penalty to models that are more complex (nonlinear). A balance is struck between the accuracy and complexity of the model, thus minimizing overfitting, optimizing the predictive power of models

• algorithm operates. A cost function M listed below describes this balance, with the α and β parameters adjusting the relative importance of the errors in the model predictions (β parameter) and the size of the neural network weights (a measure of model complexity, α parameter). where ND is the number of

Towards open-ended evolution in self-replicating molecular systems

• Herman Duim and
• Sijbren Otto

Beilstein J. Org. Chem. 2017, 13, 1189–1203, doi:10.3762/bjoc.13.118

• ) to diversify and increase in complexity. Whereas life once must have started out as a comparatively simple and primitive form, it has diversified into a vast variety of species ranging from aquatic to airborne ones. The principles governing this diversification in biological systems were already

• before, the Darwinian triad of replication, selection, and mutation in itself is not sufficient to drive the complexification of a chemical system. But what determines whether a (chemical) system is capable of growing in complexity or is condemned to remain at a low level of complexity? This is a

• the individual ribozymes. Moreover, cooperative systems are generally more stable towards parasites then autocatalytic self-replicators and are, in principle, able to gain in complexity [46][47]. In the study a ribozyme of around 200 nucleotides called Azoarcus was used. This ribozyme is made from

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• : monocrystalline, polycrystalline, solution, colloids and multiscale architectures. Steady improvements in instrumentation have made synchrotrons the most flexible intense X-ray source. The wide range of applications of synchrotron radiation is commensurate with the structural diversity and complexity of the

• dramatic impact on the throughput and on the complexity of the structures determined. However, despite the development in nano-volume liquid handling for high-throughput screens, the crystallization of biological macromolecules still represents an important bottleneck in structure determination. Nanoliter

• the crystal size, it maximizes the diffraction signal-to-noise and reduces background scattering from crystal holder and mother liquor. New beamline graphical control software [24][25][26] facilitates beamline operation without exposing the complexity of the hardware. This allows the implementation of

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

• carry over the basic metabolic pathways that drive the pursuit of life. Keywords: algorithmic complexity; complementarity; phagocytosis: reticulum; Turing Machine; Introduction “Man is the measure of all things” (Protagoras), making it difficult to get around an anthropocentric view of the reality

An eco-compatible strategy for the diversity-oriented synthesis of macrocycles exploiting carbohydrate-derived building blocks

• Sushil K. Maurya and
• Rohit Rana

Beilstein J. Org. Chem. 2017, 13, 1106–1118, doi:10.3762/bjoc.13.110

• size, shape, heteroatoms, functional groups and stereo chemical complexity for selective binding [4]. The diversity-oriented synthesis (DOS), an algorithm in organic chemistry used to generate diverse molecules that include two-directional coupling, ring expansion methods, multidimensional coupling and