Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

• Vinila N. Viswanathan,
• Arun D. Rao,
• Upendra K. Pandey,
• Arul Varman Kesavan and
• Praveen C. Ramamurthy

Beilstein J. Org. Chem. 2017, 13, 863–873, doi:10.3762/bjoc.13.87

• recently reaching remarkable PCEs of up to 11.7% [5][6][7]. However, the diversity of monomeric units and the numerous available reports on the structural complexity of D–A–D-conjugated p-type polymers indicate that there is still need for new materials which can further improve the performance of OPV

Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems

• Katarina Kemper,
• Max Hirte,
• Markus Reinbold,
• Monika Fuchs and
• Thomas Brück

Beilstein J. Org. Chem. 2017, 13, 845–854, doi:10.3762/bjoc.13.85

• ), artemisinin [2] (antimalarial agent) and α-pinene [3] (antibiotic, anti-inflammatory). Apart from bioactive compounds with applications as drugs/pharmaceuticals [4] or in the nutrition or agricultural sector, isoprenoids of minor structural complexity are used as bulk chemicals or fuel additives [5][6]. To

• diterpenes (geranylgeranyl diphosphate, GGPP) [35]. Terpene synthases Interestingly, plant metabolism can convert the universal aliphatic diterpene precursor GGPP into thousands of different terpene structures with high structural complexity and elaborately functional decorations [41]. While the structural

• about engineering the native pathway for isoprenoid precursor formation in E. coli, MEP, proves its complexity. Computational approaches that involve flux-balance analyses can redirect empirical screening for optimized systems towards guided engineering to overcome metabolic bottlenecks and identify

DMAP-assisted sulfonylation as an efficient step for the methylation of primary amine motifs on solid support

• Johnny N. Naoum,
• Koushik Chandra,
• Dorit Shemesh,
• R. Benny Gerber,
• Chaim Gilon and
• Mattan Hurevich

Beilstein J. Org. Chem. 2017, 13, 806–816, doi:10.3762/bjoc.13.81

• addition to a protected Nα-alkylated glycine in the sequence. Because of its complexity, 1SW-1 was selected as our model in order to evaluate the efficiency of multiple sites N-methylation synthesis. The synthesis of 1SW-1 using the standard protocols yielded a crude mixture in which the isolation of the

Cyclodextrins tethered with oligolactides – green synthesis and structural assessment

• Cristian Peptu,
• Mihaela Balan-Porcarasu,
• Alena Šišková,
• Ľudovít Škultéty and
• Jaroslav Mosnáček

Beilstein J. Org. Chem. 2017, 13, 779–792, doi:10.3762/bjoc.13.77

• -containing polymers while simplifying the complexity induced by multifunctional initiator through partial benzylation of the β-CD resulting in a CD-diol. Also, the ROP of D,L-LA catalyzed by 4-dimethylaminopyridine and initiated by all 21 OH groups of β-CD was employed by Xu et al. [15]. However, the above

• capacity or even degradability in different environments will depend on their structure which is therefore crucially important to be uncovered at the molecular level. Nevertheless, to completely understand the related structural issues is a difficult task due to the level of complexity of such products

• analyzed F2 fractions was also confirmed by GPC of all F2 fractions. It was observed that in each case the GPC curves were bimodal with dispersity of around 1.6 (Table 1). Exact evaluation of the resulted products was prevented due to the complexity of the mixtures containing CD-LA, PLA and L-LA. The MALDI

How and why kinetics, thermodynamics, and chemistry induce the logic of biological evolution

• Addy Pross and
• Robert Pascal

Beilstein J. Org. Chem. 2017, 13, 665–674, doi:10.3762/bjoc.13.66

• elaborate processes, in particular that of increasing complexity, are clearly involved. As an example of a higher degree of complexity, out-of-equilibrium self-assembly can be observed when reactants that have no affinity for self-assembly in themselves, can be converted upon activation into transient

• (leading to Lotka–Volterra oscillating behaviour, Figure 4), is to lead to an increase in the system’s complexity. This aspect will be discussed subsequently. Stability and complexity Even though the Second Law drive towards equilibrium is brought about through the minimisation of the Gibbs free energy of

• is an increase in complexity, suggesting that it is not just stability/persistence which increases, and that whatever quantities are being optimised, they should also include a term related, whether directly or indirectly, to complexity. It is worth noting that the meaning of complexity considered

Secondary metabolome and its defensive role in the aeolidoidean Phyllodesmium longicirrum, (Gastropoda, Heterobranchia, Nudibranchia)

• Alexander Bogdanov,
• Cora Hertzer,
• Stefan Kehraus,
• Samuel Nietzer,
• Sven Rohde,
• Peter J. Schupp,
• Heike Wägele and
• Gabriele M. König

Beilstein J. Org. Chem. 2017, 13, 502–519, doi:10.3762/bjoc.13.50

• corals carried out by La Barre et al. focused on feeding deterrence of aqueous coral extracts against G. affinis [59]. The remarkable result was that the fish deterrent activity and ichthyotoxicity not necessarily correlated, demonstrating the complexity of such ecological studies. The comprehensive

Biosynthetic origin of butyrolactol A, an antifungal polyketide produced by a marine-derived Streptomyces

• Enjuro Harunari,
• Hisayuki Komaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2017, 13, 441–450, doi:10.3762/bjoc.13.47

• /carbohydrate/nucleic acid derivatives [1][2]. One of the largest groups of bacterial secondary metabolites is polyketide from which a range of clinically used drugs have been developed. Polyketides still remain in the focus of drug development because of their structural complexity that can provide attractive

Adsorption of RNA on mineral surfaces and mineral precipitates

• Elisa Biondi,
• Yoshihiro Furukawa,
• Jun Kawai and
• Steven A. Benner

Beilstein J. Org. Chem. 2017, 13, 393–404, doi:10.3762/bjoc.13.42

• "Pyrex® prebiotic chemistry" that dominates the field. However, in addition to creating an opportunity, this complexity creates problems, both intrinsic and experimental. For every constructive reaction that might be catalyzed by a mineral, the potential exists for that mineral to catalyze a destructive

• pure mineral, the catalysis of interest can occur in defects in its crystalline surface. All of these problems are difficult to manage in a controlled laboratory environment. How are we to explore this new complexity as we accommodate those who "plead" for a role for mineralogy in models for the origin

• analogous crystal forms (as do the lead arsenate mimetite and the lead phosphate pyromorphite). Further, vanadinite adsorbed RNA well (72%). However, lead strikes us as being an unlikely element to have been involved in prebiotic chemistry (but see refs. [20][21][22]). Adding complexity The alkaline earth

Versatile synthesis of the signaling peptide glorin

• Robert Barnett,
• Daniel Raszkowski,
• Thomas Winckler and
• Pierre Stallforth

Beilstein J. Org. Chem. 2017, 13, 247–250, doi:10.3762/bjoc.13.27

• evolutionary transition [1]. This transition has occurred not only once, in fact more than 25 independent instances of this event are known. The resulting increase in biological complexity requires fine-tuned differentiation and cell–cell communication mechanisms. The social amoebae are exquisite organisms to

Continuous-flow synthesis of highly functionalized imidazo-oxadiazoles facilitated by microfluidic extraction

• Ananda Herath and
• Nicholas D. P. Cosford

Beilstein J. Org. Chem. 2017, 13, 239–246, doi:10.3762/bjoc.13.26

• are readily available (purchased or easily synthesized) than acyl chlorides allowing access to greater diversity. Finally, this method is easily adapatable to the synthesis of compounds with increasing complexity, as shown by our next set of experiments. To demonstrate the utility of the newly

Interactions between photoacidic 3-hydroxynaphtho[1,2-b]quinolizinium and cucurbit[7]uril: Influence on acidity in the ground and excited state

• Jonas Becher,
• Daria V. Berdnikova,
• Darinka Dzubiel,
• Heiko Ihmels and
• Phil M. Pithan

Beilstein J. Org. Chem. 2017, 13, 203–212, doi:10.3762/bjoc.13.23

• ). Unfortunately, the binding constants could not be determined from the titration data at pH 7 due to the complexity of the system resulting from several equilibrium processes. Thus, at pH > 6 the deprotonation of ligand 2 starts that – together with the host–guest equilibria – makes the system too complex for

Self-optimisation and model-based design of experiments for developing a C–H activation flow process

• Alexander Echtermeyer,
• Yehia Amar,
• Jacek Zakrzewski and
• Alexei Lapkin

Beilstein J. Org. Chem. 2017, 13, 150–163, doi:10.3762/bjoc.13.18

• this is the complexity of chemistry and the duration of time required for the development of good mechanistic models. A game changer in this area is the recently emerged field of automated continuous-flow experiments driven by algorithms for sequential design of experiments (DoE), which significantly

• model structure could be identified. There would be many practical cases when due to complexity of chemistry it would be unrealistic to develop a physical model within a reasonable timescale. Then the ‘black-box’ approach is a viable option. Conclusion In conclusion, we present an approach of using

3D printed fluidics with embedded analytic functionality for automated reaction optimisation

• Andrew J. Capel,
• Andrew Wright,
• Matthew J. Harding,
• George W. Weaver,
• Yuqi Li,
• Russell A. Harris,
• Steve Edmondson,
• Ruth D. Goodridge and
• Steven D. R. Christie

Beilstein J. Org. Chem. 2017, 13, 111–119, doi:10.3762/bjoc.13.14

• part to be held within by a commercially available sprung clip. The flow cell itself had a path length of 6 mm. One of the unique features of using AM to manufacture this type of part is that manufacturing costs are directly proportional to the volume of material used and not the complexity of the

Biochemical and structural characterisation of the second oxidative crosslinking step during the biosynthesis of the glycopeptide antibiotic A47934

• Veronika Ulrich,
• Clara Brieke and
• Max J. Cryle

Beilstein J. Org. Chem. 2016, 12, 2849–2864, doi:10.3762/bjoc.12.284

• Biochemistry and Molecular Biology and ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia 10.3762/bjoc.12.284 Abstract The chemical complexity and biological activity of the glycopeptide antibiotics (GPAs) stems from their unique crosslinked structure

Computational methods in drug discovery

• Sumudu P. Leelananda and
• Steffen Lindert

Beilstein J. Org. Chem. 2016, 12, 2694–2718, doi:10.3762/bjoc.12.267

• databases. One limitation of this approach can be attributed to its high complexity. When a high-resolution target structure is available, ligand growing programs such as biochemical and organic model builder (BOMB) can be used to design ligands that bind to the target without using ligand databases [155

Synthesis of polyhydroxylated decalins via two consecutive one-pot reactions: 1,4-addition/aldol reaction followed by RCM/syn-dihydroxylation

• Michał Malik and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2016, 12, 2602–2608, doi:10.3762/bjoc.12.255

• ]. Although this approach is challenging in terms of diastereoselectivity (up to eight possible diastereoisomers), it enables a rapid increase of molecular complexity. The major diastereoisomer of 11 can be then subjected to the assisted tandem catalytic sequence: RCM reaction, followed by the reuse of the

• efficient way for the preparation of highly oxygenated trans-decalins. It offers a possibility to significantly increase molecular complexity in just two steps. General structures of mono- and bicyclic carbasugars. Possible course of the syn-dihydroxylation leading to 27, 28, and 29. Approach to the

A new paradigm for designing ring construction strategies for green organic synthesis: implications for the discovery of multicomponent reactions to build molecules containing a single ring

• John Andraos

Beilstein J. Org. Chem. 2016, 12, 2420–2442, doi:10.3762/bjoc.12.236

• transformations are possible in that vast chemical space. In addition, graph theoretical methods have been used to quantify various aspects of synthesis planning and efficiency including codification of construction reactions [103][104][105], connectivity analysis [106], complexity analysis [107][108][109][110

A detailed view on 1,8-cineol biosynthesis by Streptomyces clavuligerus

• Jan Rinkel,
• Patrick Rabe,
• Laura zur Horst and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 2317–2324, doi:10.3762/bjoc.12.225

• complexity is reached within the largest, the terpenoids. An estimated number of 75,000 different compounds are known from all kinds of organisms including plants [1], bacteria [2][3][4][5], fungi [6] and, as recently shown, even social amoebae [7]. These molecules are all made from only a handful of linear

High performance p-type molecular electron donors for OPV applications via alkylthiophene catenation chromophore extension

• Paul B. Geraghty,
• Calvin Lee,
• Jegadesan Subbiah,
• Wallace W. H. Wong,
• James L. Banal,
• Mohammed A. Jameel,
• Trevor A. Smith and
• David J. Jones

Beilstein J. Org. Chem. 2016, 12, 2298–2314, doi:10.3762/bjoc.12.223

• structural complexity in the as-cast thin films. BMR shows two emission peaks at 670 nm and 704 nm with a long tail at around 800 nm. A number of absorption peaks are evident for BMR, Figure 5a and d, and these may represent the multiple environments for emission. BBR, BTR and BQR show surprisingly

Isosorbide and dimethyl carbonate: a green match

• Fabio Aricò and
• Pietro Tundo

Beilstein J. Org. Chem. 2016, 12, 2256–2266, doi:10.3762/bjoc.12.218

• that affect the formation of the product can be efficiently shifted towards isosorbide preventing any further reactions (Scheme 2). Best results were achieved when an excess of NaOMe was employed (entry 3, Table 2). The necessity of an excess of base might be ascribed to the complexity of this one-pot

An effective one-pot access to polynuclear dispiroheterocyclic structures comprising pyrrolidinyloxindole and imidazothiazolotriazine moieties via a 1,3-dipolar cycloaddition strategy

• Alexei N. Izmest’ev,
• Galina A. Gazieva,
• Natalya V. Sigay,
• Sergei A. Serkov,
• Valentina A. Karnoukhova,
• Vadim V. Kachala,
• Alexander S. Shashkov,
• Igor E. Zanin,
• Angelina N. Kravchenko and
• Nina N. Makhova

Beilstein J. Org. Chem. 2016, 12, 2240–2249, doi:10.3762/bjoc.12.216

• ; nitrogen heterocycles; spiro compounds; Introduction A global trend in modern organic chemistry is the design of molecular systems with various degrees of complexity to maximize the incorporation of useful properties while optimizing cost and efficiency [1]. A very extended and powerful approach for

Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

• Pierre Boufflet,
• Sebastian Wood,
• Jessica Wade,
• Zhuping Fei,
• Ji-Seon Kim and
• Martin Heeney

Beilstein J. Org. Chem. 2016, 12, 2150–2163, doi:10.3762/bjoc.12.205

• di- and triblock copolymers, which adds to the complexity of the system and makes batch-to-batch reproducibility difficult [1][2]. Particularly problematic is the lack of control over the block lengths and molecular weight for the step-growth polymerization. Indeed, the relative block lengths play a

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 stereochemical complexity from the starting material to the product. A similar development can be stated for the mechanistically closely related oxidative cyclizations of 5,6-dihydroxyalkenes and 5-hydroxyalkenes. All these processes are stereochemically predictable and the double bond geometry

Application of heterocyclic aldehydes as components in Ugi–Smiles couplings

• Katelynn M. Mason,
• Michael S. Meyers,
• Abbie M. Fox and
• Sarah B. Luesse

Beilstein J. Org. Chem. 2016, 12, 2032–2037, doi:10.3762/bjoc.12.191

• couplings in combination with post-condensation processes to efficiently increase structural complexity [8][9][10]. One of the most effective routes to polycyclic core structures uses intramolecular Diels–Alder reactions (IMDA) of tethered, substituted furans to provide stereoselective construction of

• nitrogen-containing heterocyclic systems [11][12][13]. Multicomponent coupling reactions (MCRs) have been combined with IMDA approaches to efficiently increase molecular complexity [14] and prepare complex molecular scaffolds for the synthesis of natural products [15][16]. While the Ugi–Smiles condensation

Organic chemistry meets polymers, nanoscience, therapeutics and diagnostics

• Vincent M. Rotello

Beilstein J. Org. Chem. 2016, 12, 1638–1646, doi:10.3762/bjoc.12.161

• Heterocycles in the "New Natural Products" section. I noticed a rather interesting new molecule known as rapamycin that had the vicinal tricarbonyl motif in vogue in the Wasserman group. When I suggested we go after this molecule, Harry demurred, pointing out its complexity and that "nobody would be interested