Perspective isomorphs – a new classification of molecular structures based on artistic and chemical concepts

• Jannis Neumann,
• Ansgar Schnurr and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2019, 15, 2319–2326, doi:10.3762/bjoc.15.224

• -fertilization with natural sciences. Here we show a new classification of molecular structures, so-called perspective isomorphs, applying an interdisciplinary crossing of epistemological concepts between chemistry and art. The idea is based on the notion that molecules can be classified, if they appear

• equivalent from one standpoint in a specific orientation. We termed such a group of such molecules perspective isomorphs. The general concept is outlined together with a nomenclature system. Furthermore, this concept has been visualized by artistic representations of molecules. The concept of perspective

• isomorphs and its discussions herein will extend current models and stimulate the discourse about the nature of atoms and molecules and especially their models. Keywords: art and science; nomenclature; perspective; representation in chemistry; structure; Introduction Up to now, epistemological concepts of

Genomics-inspired discovery of massiliachelin, an agrochelin epimer from Massilia sp. NR 4-1

• Jan Diettrich,
• Hirokazu Kage and
• Markus Nett

Beilstein J. Org. Chem. 2019, 15, 1298–1303, doi:10.3762/bjoc.15.128

• recognition of a far greater taxonomic diversity of microbes that can produce bioactive compounds [1][2][3]. The exploration of previously neglected taxa has been demonstrated to bear significant potential for finding new natural products and is thus highly promising from a drug discovery perspective [4][5

Halogen bonding and host–guest chemistry between N-alkylammonium resorcinarene halides, diiodoperfluorobutane and neutral guests

• Fangfang Pan,
• Mohadeseh Dashti,
• Michael R. Reynolds,
• Kari Rissanen,
• John F. Trant and
• Ngong Kodiah Beyeh

Beilstein J. Org. Chem. 2019, 15, 947–954, doi:10.3762/bjoc.15.91

• . employing substitutional disorder, achieved the co-crystallization of six components [28]. As for positional disorder, it generally indicates the same molecule or assembly can adopt more than one favourable conformation. From this perspective, disorder can be considered as a special case of a co-crystal or

Coordination chemistry and photoswitching of dinuclear macrocyclic cadmium-, nickel-, and zinc complexes containing azobenzene carboxylato co-ligands

• Jennifer Klose,
• Tobias Severin,
• Peter Hahn,
• Alexander Jeremies,
• Jens Bergmann,
• Daniel Fuhrmann,
• Jan Griebel,
• Bernd Abel and
• Berthold Kersting

Beilstein J. Org. Chem. 2019, 15, 840–851, doi:10.3762/bjoc.15.81

• ligand H2L (M = divalent or trivalent transition metal). Right: Perspective view of the bowl-shaped structure of the corresponding carboxylato complexes. Synthesized compounds and their labels. 1H NMR spectrum of 6 in CD3CN at 295 K (1.0–8.0 ppm). The resonances and assignments are listed in Table 2 and

Design, synthesis and spectroscopic properties of crown ether-capped dibenzotetraaza[14]annulenes

• Krzysztof M. Zwoliński and
• Julita Eilmes

Beilstein J. Org. Chem. 2019, 15, 617–622, doi:10.3762/bjoc.15.57

• differentiated Lewis-basic binding sites, however, from a broader perspective, the nature of the DBTAA binding site can be easily switched into a Lewis-acidic one after appropriate metal insertion (e.g., with zinc(II) ions) [33]. The crown-capped DBTAA’s were synthesized by refluxing 1,4,10-trioxa-7,13

Application of olefin metathesis in the synthesis of functionalized polyhedral oligomeric silsesquioxanes (POSS) and POSS-containing polymeric materials

• Patrycja Żak and
• Cezary Pietraszuk

Beilstein J. Org. Chem. 2019, 15, 310–332, doi:10.3762/bjoc.15.28

• cross metathesis much more readily and are clearly better than internal alkenes from the cost perspective. However, internal alkenes are less volatile and cannot produce any ethene, which makes them interesting starting materials. A slight vacuum had to be applied to reactions with terminal alkenes in

Asymmetric synthesis of a high added value chiral amine using immobilized ω-transaminases

• Antonella Petri,
• Valeria Colonna and
• Oreste Piccolo

Beilstein J. Org. Chem. 2019, 15, 60–66, doi:10.3762/bjoc.15.6

• consequence is limited to 50% maximum yield of the desired product. The second process employs non-commercial enzymes which might be a limitation in the perspective of a potential large-scale industrial application. More recently, the synthesis of the (S)-enantiomer of minor application interest has been

Lectins of Mycobacterium tuberculosis – rarely studied proteins

• Katharina Kolbe,
• Sri Kumar Veleti,
• Norbert Reiling and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2019, 15, 1–15, doi:10.3762/bjoc.15.1

• ][133] including many of the putative Mtb lectins and indeed, Mtb lectins have been poorly studied in mycobacteria. This account has thus focused on reviewing the available knowledge on Mtb lectins, which are a promising field of research with a diagnostic and therapeutic perspective in the field of

Protein–protein interactions in bacteria: a promising and challenging avenue towards the discovery of new antibiotics

• Laura Carro

Beilstein J. Org. Chem. 2018, 14, 2881–2896, doi:10.3762/bjoc.14.267

• drug discovery perspective, its structure differs significantly from the eukaryotic equivalent clamp (PCNA, proliferating cell nuclear activity) [51][57]. O’Donnell et al. first identified the structure of an inhibitor of the E. coli sliding clamp (ECSC) [58]. In the search for a molecule that binds to

• ]. Similarly to the aforementioned sliding clamp, the structural arrangement of most bacterial SSBs differs significantly to its homolog in eukaryotic cells (replication protein A, RPA) [74]. This dissimilarity could be beneficial from a drug discovery perspective because it would enable selective targeting of

Synthesis of α-D-GalpN₃-(1-3)-D-GalpN₃: α- and 3-O-selectivity using 3,4-diol acceptors

• Emil Glibstrup and
• Christian Marcus Pedersen

Beilstein J. Org. Chem. 2018, 14, 2805–2811, doi:10.3762/bjoc.14.258

• perspective, a few closely related glycosylations are shown in Scheme 4. Firstly, our own glycosylations using the 4-O-Bz variants, gave a lower yield, when using the TBDPS–TBDPS variant, of 36% [44]. The less sterically hindered Bn–TBDPS variant gave yields of 47%, which are comparable to the 3,4-diol

Targeting the Pseudomonas quinolone signal quorum sensing system for the discovery of novel anti-infective pathoblockers

• Christian Schütz and
• Martin Empting

Beilstein J. Org. Chem. 2018, 14, 2627–2645, doi:10.3762/bjoc.14.241

• of about 6 years or less [90] are quite unrealistic in this field. This actually underpins the urgency for current anti-infective discovery efforts to enable refilling the pipeline in due time before available treatment options run out. However, we believe the translational perspective for such

Nucleoside macrocycles formed by intramolecular click reaction: efficient cyclization of pyrimidine nucleosides decorated with 5'-azido residues and 5-octadiynyl side chains

• Jiang Liu,
• Peter Leonard,
• Sebastian L. Müller,
• Constantin Daniliuc and
• Frank Seela

Beilstein J. Org. Chem. 2018, 14, 2404–2410, doi:10.3762/bjoc.14.217

• functional elucidation. Energy-minimized models of the two macrocycles derived from dC (left) and dU (right) acquired by MM+ simulation using Hyperchem 8.0.10; both showing the accessibility of the Watson–Crick recognition sites. A perspective view of 8 showing the atomic numbering scheme. Displacement

Determining the predominant tautomeric structure of iodine-based group-transfer reagents by ¹⁷O NMR spectroscopy

• Nico Santschi,
• Cody Ross Pitts,
• Benson J. Jelier and
• René Verel

Beilstein J. Org. Chem. 2018, 14, 2289–2294, doi:10.3762/bjoc.14.203

• over 50 kcal/mol, a high kinetic barrier suppresses the [a → b] isomerization (Figure 1) [5][6]. With SCF3 reagent 5a/5b, structure determination was notably challenging and solely provides a solid-state structural perspective. Thus, we wondered whether a correct structural assignment of reagent 5a/b

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

Recent advances in materials for organic light emitting diodes

• Eli Zysman-Colman

Beilstein J. Org. Chem. 2018, 14, 1944–1945, doi:10.3762/bjoc.14.168

• Organic Chemistry covers novel phosphorescent and TADF materials design and their inclusion as emitters in OLEDs. Some highlights in this issue include the work of Thanh-Tuân Bui et al., who provide a welcome perspective on blue TADF materials for OLEDs in the form of a review article [2]. Cristina

A pyridinium/anilinium [2]catenane that operates as an acid–base driven optical switch

• Sarah J. Vella and
• Stephen J. Loeb

Beilstein J. Org. Chem. 2018, 14, 1908–1916, doi:10.3762/bjoc.14.165

• derivatize, [2]rotaxanes are deemed easier to fine-tune from a structural perspective than [2]catenanes. Although we were able to create an optically sensitive [2]catenane molecular shuttle with the bis(pyridinium)ethane and benzylanilinium recognition motifs, we could not achieve the true ON/OFF, bistable

Recent applications of chiral calixarenes in asymmetric catalysis

• Mustafa Durmaz,
• Erkan Halay and
• Selahattin Bozkurt

Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117

• performed using 118a–e as catalysts and isopropanol as a secondary alcohol hydride donor (Scheme 38). Although 99% ee was achieved with catalyst 118a in initial conversion stage, from the perspective of yield and enantioselectivity VANOL-derived phosphite catalyst 118d which has an extended π-delocalization

Oligonucleotide analogues with cationic backbone linkages

• Melissa Meng and
• Christian Ducho

Beilstein J. Org. Chem. 2018, 14, 1293–1308, doi:10.3762/bjoc.14.111

• systems, vide supra) as the stereoselective synthesis of stereogenic phosphate derivatives is challenging. Therefore, achiral artificial linkages such as guanidinium groups may be considered advantageous from a stereochemical perspective. For the first synthesis of a pentameric thymidinyl DNG in 1996

Stereoselective nucleophilic addition reactions to cyclic N-acyliminium ions using the indirect cation pool method: Elucidation of stereoselectivity by spectroscopic conformational analysis and DFT calculations

• Koichi Mitsudo,
• Junya Yamamoto,
• Tomoya Akagi,
• Atsuhiro Yamashita,
• Masahiro Haisa,
• Kazuki Yoshioka,
• Hiroki Mandai,
• Koji Ueoka,
• Christian Hempel,
• Jun-ichi Yoshida and
• Seiji Suga

Beilstein J. Org. Chem. 2018, 14, 1192–1202, doi:10.3762/bjoc.14.100

• physiological and pharmacological activities [1][2][3]. As many of these compounds feature asymmetric carbon atoms at the α-position of the cyclic amine, the stereoselective carbon–carbon bond formation at this position is of great importance from the perspective of drug discovery [4][5]. Meanwhile the “cation

Are dispersion corrections accurate outside equilibrium? A case study on benzene

• Tim Gould,
• Erin R. Johnson and
• Sherif Abdulkader Tawfik

Beilstein J. Org. Chem. 2018, 14, 1181–1191, doi:10.3762/bjoc.14.99

• forces Dispersion forces are a semi-classical effect coming from quantum fluctuations. Most simply, they can be viewed from the perspective of pairs of interacting fluctuating dipoles, in which a temporary dipole in one (sub)system induces a dipole in the other, and consequently lowers the total energy

Mechanochemistry of nucleosides, nucleotides and related materials

• Olga Eguaogie,
• Joseph S. Vyle,
• Patrick F. Conlon,
• Manuela A. Gîlea and
• Yipei Liang

Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81

• Strecker-type reaction could be effected in a ball mill using catalytic anhydrous ferricyanide in the presence of silica [114]. From a theoretical perspective, Hansma proposed that such mechanical energy could be supplied within moving mica sheets under high molecular crowding conditions [115]. In contrast

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

• . The general architecture of PDCs consists of three building blocks: the tumor-homing peptide, the cytotoxic agent and the biodegradable connecting linker. The aim of the current review is to provide a spherical perspective on the basic principles governing PDCs, as also the methodology to construct

• Table 2. Representative examples of PDCs targeting cancer cells Integrating the basic design principles in PDCs pinpointed above, a list of representative developed examples is analyzed below, so as to provide a spherical perspective regarding peptide–drug conjugation chemistry. Currently, there are two

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

An air-stable bisboron complex: a practical bidentate Lewis acid catalyst

• Longcheng Hong,
• Sebastian Ahles,
• Andreas H. Heindl,
• Gastelle Tiétcha,
• Andrey Petrov,
• Zhenpin Lu,
• Christian Logemann and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2018, 14, 618–625, doi:10.3762/bjoc.14.48

• attributed to the free vacant p-orbital of the boron atom leading to further transformations, such as decomposition via radicals (O2), reactions with nucleophiles (H2O) as well as the formations of adducts. From this perspective, a suitable Lewis base may form a Lewis complex and subsequently occupy the p

Mechanochemistry

• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 2372–2373, doi:10.3762/bjoc.13.234

• otherwise impossible chemical reactivity in many cases. From a green chemistry perspective, mechanochemical activation conducted by milling, shearing, pulling or ultrasonic irradiation allows for the possibility to drastically reduce the amount of solvent needed during chemical reactions, even to the point