Synthesis of dipolar molecular rotors as linkers for metal-organic frameworks

• Sebastian Hamer,
• Fynn Röhricht,
• Marius Jakoby,
• Ian A. Howard,
• Xianghui Zhang,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 1331–1338, doi:10.3762/bjoc.15.132

• compromise between the size and dipole moment of the rotor/linker has to be aimed at, and care has to be taken that the rotational barriers are as low as possible. Figure 1 shows the interaction of a pair of dipolar rotors with parallel axes at a distance of 10 Å, which is a typical distance of the linkers

• available in gram amounts for the synthesis of MOF or SURMOF structures with promising electric and optical properties. Interactions of a pair of dipolar rotors in different orientations. The axes of the rotors are parallel at a distance of 10 Å (terminal H atoms at the ethynyl units are in a plane and at

Bambusuril analogs based on alternating glycoluril and xylylene units

• Tomáš Lízal and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2019, 15, 1268–1274, doi:10.3762/bjoc.15.124

• good agreement with the structure of the 1b-1 conformer calculated by DFT. The parallel glycoluril units are placed on one side of the plane defined by the xylylene moieties. The macrocycles form a layered structure stabilized by intermolecular hydrogen bonding interaction between the carbonyl oxygens

Unexpected polymorphism during a catalyzed mechanochemical Knoevenagel condensation

• Sebastian Haferkamp,
• Andrea Paul,
• Adam A. L. Michalchuk and
• Franziska Emmerling

Beilstein J. Org. Chem. 2019, 15, 1141–1148, doi:10.3762/bjoc.15.110

• data, they represent the underlying chemical or physical processes. In order to understand the results of PCA, both scores and loadings must be scrutinized in parallel. Whereas the scores contain information regarding the samples, the loadings provide information on the variables. High loading values

• clearly separated compounds, the Raman spectra suggest the parallel presence of 1a, m3a and t3a. Multivariate curve resolution (MCR) aims to extract information on the pure compounds [27]. In our case, the time series of Raman spectra may be considered as a superposition of all compounds present at a

Molecular recognition using tetralactam macrocycles with parallel aromatic sidewalls

• Dong-Hao Li and
• Bradley D. Smith

Beilstein J. Org. Chem. 2019, 15, 1086–1095, doi:10.3762/bjoc.15.105

• Dong-Hao Li Bradley D. Smith Department of Chemistry and Biochemistry, University of Notre Dame, 236 Nieuwland Science Hall, Notre Dame, Indiana 46556, United States 10.3762/bjoc.15.105 Abstract This review summarizes the supramolecular properties of tetralactam macrocycles that have parallel

• units connected by two parallel aromatic sidewalls and we have chosen to highlight them as one of the few classes of macrocyclic host molecules that have an amphiphilic cavity. As described below, the range of guest structures that bind within the cavity of this host family is quite broad. In the

• tetralactam A reported by the Leigh group in the mid 1990s [27][28]. The macrocycle has two parallel 1,4-phenylene sidewalls and when the two bridging units are 1,3-benzene dicarboxamides (X = CH) there is considerable conformational flexibility. For example, the empty macrocycle can easily adopt a

A chemically contiguous hapten approach for a heroin–fentanyl vaccine

• Yoshihiro Natori,
• Candy S. Hwang,
• Lucy Lin,
• Lauren C. Smith,
• Bin Zhou and
• Kim D. Janda

Beilstein J. Org. Chem. 2019, 15, 1020–1031, doi:10.3762/bjoc.15.100

• obtain an aldehyde that could then be used in a reductive amination. Beginning with the commercially available 4-(4-bromophenyl)butanoic acid, an alkene was installed with a Suzuki reaction, which in turn underwent ozonolysis to give 21, shown in Scheme 4. In parallel, a commercially available piperidine

• the same linker as HF-4, its lengthy epitope actually required a different, but parallel synthetic strategy. The same commercially available piperidine used to obtain 24 was instead acylated with phthaloyl-protected aminopropanoyl chloride, deprotected, and reductively aminated with 21 to give 33

• , 86%; c) H2NNH2, EtOH, 89%; d) 1-phenethylpiperidin-4-one, NaBH(OAC)3, AcOH, 0 °C to rt, 92%. General outline of HF-5, HF-8, HF-9 synthesis from fentanyl intermediates 28 and 46, and heroin intermediates 16, and 36. Parallel synthesis of fentanyl domains 25 and 34, for HF-4 and HF-6, respectively

New terpenoids from the fermentation broth of the edible mushroom Cyclocybe aegerita

• Frank Surup,
• Florian Hennicke,
• Nadine Sella,
• Maria Stroot,
• Steffen Bernecker,
• Sebastian Pfütze,
• Marc Stadler and
• Martin Rühl

Beilstein J. Org. Chem. 2019, 15, 1000–1007, doi:10.3762/bjoc.15.98

• verify this assumption. Conclusion We identified bovistol A (1) as the main metabolite of C. aegerita in cultures. In parallel, we isolated its new disesquiterpenoid derivatives bovistol B (2) and C (3) as well as the new protoilludane pasteurestin C (4). By a qPCR approach, we were able to link the

Tuning the stability of alkoxyisopropyl protection groups

• Zehong Liang,
• Henna Koivikko,
• Mikko Oivanen and
• Petri Heinonen

Beilstein J. Org. Chem. 2019, 15, 746–751, doi:10.3762/bjoc.15.70

• chromatography without degradation. The compatibility of these protecting groups in parallel use with benzoyl and silyl groups was verified. The stabilities of the different alkoxy acetal protecting groups were compared by following the kinetics of their hydrolysis at 25.0 °C in buffered solutions through an

Design of indole- and MCR-based macrocycles as p53-MDM2 antagonists

• Constantinos G. Neochoritis,
• Maryam Kazemi Miraki,
• Eman M. M. Abdelraheem,
• Ewa Surmiak,
• Tryfon Zarganes-Tzitzikas,
• Beata Łabuzek,
• Tad A. Holak and
• Alexander Dömling

Beilstein J. Org. Chem. 2019, 15, 513–520, doi:10.3762/bjoc.15.45

• bear a heteroatom in the 4-position as oxygen or sulfur (Y = O, S, Scheme 2) were employed in order to enhance the diversity of our macrocycles [4]. Thus, in a parallel way, we readily synthesized 12 different amino acids which were subsequently subjected to the Ugi macrocyclization. After quite some

Silanediol versus chlorosilanol: hydrolyses and hydrogen-bonding catalyses with fenchole-based silanes

• Falco Fox,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2019, 15, 167–186, doi:10.3762/bjoc.15.17

• ). For 8ax the OH group is parallel situated to the biaryl axis. For 8eq the OH group is orthogonal oriented to the biaryl axis. The fenchyl groups are abbreviated with (*) for more clarity. Computed hydrolyses of BIFOXSiCl2 (7) to BIFOXSiCl(OH) 8ax and BIFOXSiCl(OH) 8eq and subsequent computed

Adhesion, forces and the stability of interfaces

• Robin Guttmann,
• Johannes Hoja,
• Christoph Lechner,
• Reinhard J. Maurer and
• Alexander F. Sax

Beilstein J. Org. Chem. 2019, 15, 106–129, doi:10.3762/bjoc.15.12

• stabilization of parallel alkane chains, as well as the stabilization of aromatic molecules adsorbed to graphene or carbon nanotubes. Furthermore, we found that the stabilization energy of an adsorbent and several small adsorbate molecules increases when the latter are in close contact with each other. This

• range, but it allows to understand the transferability of group contributions of, for example, pairs of CH2 in two parallel aligned alkane chains. For the interaction of atoms or small molecules with extended metal surfaces, the concept of near-sightedness of dispersion does not apply, because the

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

• membrane is surrounded by a peptidoglycan layer (PG) consisting of multiple, parallel glycan chains of alternating (1→4)-linked subunits of N-acetyl-β-D-glucosamine and N-acetyl- or N-glycolyl-β-D-muramic acid, crosslinked via short conserved oligopeptide stems [44][45]. The PG is covalently attached to

Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region

• Aude-Héloise Bonardi,
• Frédéric Dumur,
• Guillaume Noirbent,
• Jacques Lalevée and
• Didier Gigmes

Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282

• excited state energy and redox potentials to interact with additives [13]. Parallel to this, the environmental issues impose the use of new polymerization methods that are safer for the manipulator, contribute to lower the amount of released volatile organic compounds and can reduce the energy consumption

• . Parallel to this, 4CzIPN was also used as an organoredox catalyst for the alkylation of heteroarenes [85], the oxidation of silicates [86], the alkylation of imines [87], the α-arylation/heteroarylation of 2-trifluoroboratochromanones [88]. In these different situations, comparisons with reference

MoO₃ on zeolites MCM-22, MCM-56 and 2D-MFI as catalysts for 1-octene metathesis

• Hynek Balcar,
• Martin Kubů,
• Naděžda Žilková and
• Mariya Shamzhy

Beilstein J. Org. Chem. 2018, 14, 2931–2939, doi:10.3762/bjoc.14.272

• oligomerization in these blank experiments is several times higher than that achieved over metathesis catalysts: it may be due to the partial capping of support acid sites with Mo species catalysts and also due the parallel consumption of 1-octene in metathesis. Figure 5b shows oligomerization of 1-octene, 2

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

• Yo Hiranoi and
• Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

• developed based on well-defined metal complexes such as metalloporphyrins and metal–salen complexes [15][16][17][18][19][20][21]. In parallel to the development of catalysts, new polyester materials also were prepared by employing unprecedented monomers or by the combination with other polymerization

Dispersion-mediated steering of organic adsorbates on a precovered silicon surface

• Lisa Pecher,
• Sebastian Schmidt and
• Ralf Tonner

Beilstein J. Org. Chem. 2018, 14, 2715–2721, doi:10.3762/bjoc.14.249

• placing the cyclooctyne molecule in an upright orientation (molecular C2 axis aligned parallel to the z axis of the cell), with the triple bond aligned parallel to the y axis of the cell, the triple-bond centre located vertically above a lower surface atom (Sidown) at a height corresponding to a vertical

• with one adsorbate 1 and unit cell used in the PES scans (orientation of second adsorbate and scan path indicated) shown in Figure 5. Frozen PES scans of 1 along path indicated in Figure 4 (C2 axis parallel to z, C≡C parallel to y, Δz(Siup–Ctriple) = 5 Å) on (a) the clean and (b) the precovered surface

Pathoblockers or antivirulence drugs as a new option for the treatment of bacterial infections

• Matthew B. Calvert,
• Varsha R. Jumde and
• Alexander Titz

Beilstein J. Org. Chem. 2018, 14, 2607–2617, doi:10.3762/bjoc.14.239

• to a decline in the development of new antibiotics, with very few new antibiotics addressing a novel mode of action being brought to the market over the last four decades [3]. In parallel with the decline of new antibiotics, resistance towards these widely used drugs has evolved at a high pace and

Comparative cell biological study of in vitro antitumor and antimetastatic activity on melanoma cells of GnRH-III-containing conjugates modified with short-chain fatty acids

• Eszter Lajkó,
• Sarah Spring,
• Rózsa Hegedüs,
• Beáta Biri-Kovács,
• Sven Ingebrandt,
• Gábor Mező and
• László Kőhidai

Beilstein J. Org. Chem. 2018, 14, 2495–2509, doi:10.3762/bjoc.14.226

• inducer activity of Dau was also manifested in the pattern of cell cycle phases; the percentage of sub-G1 phase representing apoptotic cells (cell fragments) was increased after cells were treated with 10−5 M Dau up to 14.1% compared with 3.4% of the control. In parallel, a decrease in the proportions of

• modulator effect of the conjugates The dissemination of tumor cells is an important aspect of the tumor progression and could significantly affect the success of the targeted tumor therapy, as well. The first crucial steps in metastasis cascade are the impaired adhesion contacts and in parallel the

• area: 84.2 ± 3.32 – 92.5 ± 3.5; thickness: 95.7 ± 1.94 – 103.1 ± 2.21). Opposite tendencies were shown for [4Lys(Bu)]-GnRH-III(Dau=Aoa), it could increase slightly, but significantly the surface area (114.0 ± 5.64, p < 0.05) and in parallel reduce the optical thickness (85.7 ± 1.85, p < 0.01) at 10−6 M

Microfluidic light-driven synthesis of tetracyclic molecular architectures

• Javier Mateos,
• Nicholas Meneghini,
• Marcella Bonchio,
• Nadia Marino,
• Tommaso Carofiglio,
• Xavier Companyó and
• Luca Dell’Amico

Beilstein J. Org. Chem. 2018, 14, 2418–2424, doi:10.3762/bjoc.14.219

• (up to >98%) and virtually complete diastereocontrol (>20:1 dr). The method is easily scaled-up to a parallel setup, furnishing 948 mg of product over a 14 h reaction time. Finally, a series of manipulations of the tetracyclic scaffold obtained gave access to valuable precursors of biologically active

• spanning from 41% to 72% (Figure 3). In order to demonstrate the easy scalability of the present method (Scheme 1) two MFPs were used in a parallel setup producing 948 mg of 4a after 14 h with an overall productivity rate of 0.196 mmol·h−1 [15]. Subsequently, a series of manipulations were conducted on

• or 5. Generality and limits of the light-driven [4 + 2] cyclization reaction between 2-MBP 1a–g and coumarins 2a–c under MFP setup. *Residence time was 60 min. Generality and limits of the light-driven [4 + 2] cyclization reaction between 2-MBP 1a–f and chromone (3a) under MFP setup. MFP parallel

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

• ellipsoids are drawn at the 50% probability level and H-atoms are shown as small spheres of arbitrary size. Hydrogen bonds are shown as dashed lines. The crystal packing of 8 shows the intramolecular hydrogen-bonding network (projection parallel to the x-axis). N- and S-conformation for cyclonucleoside 8. B

A challenging redox neutral Cp*Co(III)-catalysed alkylation of acetanilides with 3-buten-2-one: synthesis and key insights into the mechanism through DFT calculations

• Andrew Kenny,
• Alba Pisarello,
• Arron Bird,
• Paula G. Chirila,
• Alex Hamilton and
• Christopher J. Whiteoak

Beilstein J. Org. Chem. 2018, 14, 2366–2374, doi:10.3762/bjoc.14.212

• energy difference between the C–H activation and C–C bond formation steps makes identification of the rate limiting step difficult by DFT calculations alone, however, parallel kinetic isotope effect (KIE) experiments do suggest that the C–H activation step is not rate limiting (KIE = 1.3), which is not

Non-metal-templated approaches to bis(borane) derivatives of macrocyclic dibridgehead diphosphines via alkene metathesis

• Tobias Fiedler,
• Michał Barbasiewicz,
• Michael Stollenz and
• John A. Gladysz

Beilstein J. Org. Chem. 2018, 14, 2354–2365, doi:10.3762/bjoc.14.211

• the form found in a confirming crystal structure [6]. Parallel reactions were conducted with Grubbs' second generation catalyst and the nitro-Grela catalyst [36]. However, the combined yields of 2 diminished. 2. Diphosphorus precursors Since the yields of the cage like diphosphine diboranes 2·2BH3 in

• easily deprotected to give the respective isomers of the dibridgehead diphosphine 2 in high yields. Since phosphine oxides are also easily converted to phosphines, one could consider parallel approaches to 2 via metatheses of the phosphine oxide (O=)P((CH2)6CH=CH2)3 (1(=O)) or diphosphine dioxide (H2C=CH

Catalyst-free synthesis of 4-acyl-NH-1,2,3-triazoles by water-mediated cycloaddition reactions of enaminones and tosyl azide

• Lu Yang,
• Yuwei Wu,
• Yiming Yang,
• Chengping Wen and
• Jie-Ping Wan

Beilstein J. Org. Chem. 2018, 14, 2348–2353, doi:10.3762/bjoc.14.210

• byproduct (entry 1, Table 1). Varying the additive to AcOH didn’t lead to an improved result (entry 2, Table 1). To our delight, the parallel entry without using any catalyst or additive afforded 3a with identically good yield (entry 3, Table 1). With this encouraging result, we then carried out a

Cobalt-catalyzed peri-selective alkoxylation of 1-naphthylamine derivatives

• Jiao-Na Han,
• Cong Du,
• Xinju Zhu,
• Zheng-Long Wang,
• Yue Zhu,
• Zhao-Yang Chu,
• Jun-Long Niu and
• Mao-Ping Song

Beilstein J. Org. Chem. 2018, 14, 2090–2097, doi:10.3762/bjoc.14.183

• radical approach may be involved in the reaction. Moreover, in the parallel experiments, a KIE value of 1.1 was observed between 1a or [D1]-1a with 2a, which indicates that Co-catalyzed C–H bond cleavage should not be the rate determining step (Scheme 3, reaction 3). On the basis of the above studies and

Assessing the possibilities of designing a unified multistep continuous flow synthesis platform

• Mrityunjay K. Sharma,
• Roopashri B. Acharya,
• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2018, 14, 1917–1936, doi:10.3762/bjoc.14.166

• experimental set-ups and even automated self-optimizing platforms were also tested [33]. The natural evolution was an archetype for the multistep flow synthesis. The integration of in-line separation has taken the confidence of the synthesis community one step ahead [21][34][35]. In parallel to this, in-line

A hemicryptophane with a triple-stranded helical structure

• Augustin Long,
• Olivier Perraud,
• Erwann Jeanneau,
• Christophe Aronica,
• Jean-Pierre Dutasta and
• Alexandre Martinez

Beilstein J. Org. Chem. 2018, 14, 1885–1889, doi:10.3762/bjoc.14.162

• parallel peptide chains coil about each other in a triple stranded left-handed helical structure. Its high thermal and mechanical stability results mainly from the numerous hydrogen bonds found in the triple helix framework [2]. Bioinspired structures, based on peptide backbones, have been built, allowing