Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

• used, then ent-236•+ can be deprotonated, and therefore racemised faster than 236•+, leading to a build-up of one enantiomer. This process initially achieved an er of 86:14, but with the inclusion of a complementary chiral HAT catalyst 237 and a radical scavenger (Ph3CH), the er could be improved to 96

Host–guest interaction of cucurbit[8]uril with oroxin A and its effect on the properties of oroxin A

• Zhishu Zeng,
• Jun Xie,
• Guangyan Luo,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 2332–2337, doi:10.3762/bjoc.16.194

• –guest interactions between oroxin A (OA) and cucurbit[8]uril (Q[8]) using 1H NMR, MS, UV–vis and IR spectroscopy. The results showed that OA and Q[8] formed an inclusion compound (OA@Q[8]) with a molar ratio of 1:1 and a binding constant of 1.299 × 107 L·mol−1. In addition, the effect of Q[8] on the

• the inclusion compound with Q[8]. Keywords: cucurbit[8]uril; host–guest interaction; inclusion complex; oroxin A; properties; Introduction Cucurbit[n]urils (Q[n]s) are a family of macrocyclic cage compounds synthesized by the condensation of glycoluril and formaldehyde in a strong acidic solution [1

• properties of OA. Our results provide an approach and theoretical basis for the development and utilization of oroxin A. Compared with the literature [31][32], it is found that although baicalein, oroxin B and oroxin A have the same aglycone, but the complex inclusion modes with Q[8] are different, It shows

Tools for generating and analyzing glycan microarray data

• Akul Y. Mehta,
• Jamie Heimburg-Molinaro and
• Richard D. Cummings

Beilstein J. Org. Chem. 2020, 16, 2260–2271, doi:10.3762/bjoc.16.187

• growing resource for the inclusion of data from multiple sources for glycoinformatics [41]. A component of the project involves the creation of a glycan microarray data repository, whereby anyone can go to a website and deposit and view glycan microarray data, along with the metadata associated with the

GlypNirO: An automated workflow for quantitative N- and O-linked glycoproteomic data analysis

• Toan K. Phung,
• Cassandra L. Pegg and
• Benjamin L. Schulz

Beilstein J. Org. Chem. 2020, 16, 2127–2135, doi:10.3762/bjoc.16.180

• . Proportional data analysis and final output In order to allow comparisons of site-specific glycoform abundance and occupancy between different samples, the proportion of each glycoform was calculated with and without inclusion of unglycosylated peptides. For calculation of proportion, glycosylation status was

How and why plants and human N-glycans are different: Insight from molecular dynamics into the “glycoblocks” architecture of complex carbohydrates

• Carl A. Fogarty,
• Aoife M. Harbison,
• Amy R. Dugdale and
• Elisa Fadda

Beilstein J. Org. Chem. 2020, 16, 2046–2056, doi:10.3762/bjoc.16.171

• glycans sequence can alter their 3D structure and conformational dynamics, ultimately regulating recognition [19]. In this work we use molecular dynamics (MD) simulations to analyse the effects of the inclusion of motifs typically found in plants and invertebrates N-glycans and immunogenic in mammals [20

One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: theoretical evidence for an asynchronous concerted pathway

• Esra Demir,
• Ozlem Sari,
• Yasin Çetinkaya,
• Ufuk Atmaca,
• Safiye Sağ Erdem and
• Murat Çelik

Beilstein J. Org. Chem. 2020, 16, 1805–1819, doi:10.3762/bjoc.16.148

• likely to be rate-determining for both reaction mechanisms. Besides, explicit inclusion of water molecules is crucial for lowering the energy barrier making the process plausible without changing the nature of the rate determining step of the formation of 9f. Our computational results adequately explain

Antibacterial scalarane from Doriprismatica stellata nudibranchs (Gastropoda, Nudibranchia), egg ribbons, and their dietary sponge Spongia cf. agaricina (Demospongiae, Dictyoceratida)

• Cora Hertzer,
• Stefan Kehraus,
• Nils Böhringer,
• Fontje Kaligis,
• Robert Bara,
• Dirk Erpenbeck,
• Gert Wörheide,
• Till F. Schäberle,
• Heike Wägele and
• Gabriele M. König

Beilstein J. Org. Chem. 2020, 16, 1596–1605, doi:10.3762/bjoc.16.132

• inclusion of species that have since been discovered to be members of other genera. Additionally, a splitting of generic groups into several genera and resurrection of old names increased the confusion [39][42][46][47][48][49]. To classify specialized metabolites in the Chromodorididae in a meaningful way

Mechanochemical green synthesis of hyper-crosslinked cyclodextrin polymers

• Alberto Rubin Pedrazzo,
• Fabrizio Caldera,
• Marco Zanetti,
• Silvia Lucia Appleton,
• Nilesh Kumar Dhakar and
• Francesco Trotta

Beilstein J. Org. Chem. 2020, 16, 1554–1563, doi:10.3762/bjoc.16.127

• were obtained only with βNS-CDI 1:8. Even in case of βNS-CDI 1:8, if treated for 8 h in H2O at 40 °C (0.40% N), presented a low amount (≈0) of reactive IM, therefore the reaction did not occur at all, leading only to an inclusion complex with the dyes, which could be easily removed through a PS

[3 + 2] Cycloaddition with photogenerated azomethine ylides in β-cyclodextrin

• Margareta Sohora,
• Leo Mandić and
• Nikola Basarić

Beilstein J. Org. Chem. 2020, 16, 1296–1304, doi:10.3762/bjoc.16.110

• Zagreb, Croatia 10.3762/bjoc.16.110 Abstract Stability constants for the inclusion complexes of cyclohexylphthalimide 2 and adamantylphthalimide 3 with β-cyclodextrin (β-CD) were determined by 1H NMR titration, K = 190 ± 50 M−1, and K = 2600 ± 600 M−1, respectively. Photochemical reactivity of the

• inclusion complexes 2@β-CD and 3@β-CD was investigated, and we found out that β-CD does not affect the decarboxylation efficiency, while it affects the subsequent photochemical H-abstraction, resulting in different product distribution upon irradiation in the presence of β-CD. The formation of ternary

• systems for the control of photoreactivity. Keywords: [3 + 2] cycloadditions; β-cyclodextrin; inclusion complexes; photochemistry; phthalimides; Introduction Cycloadditions are highly useful reactions in organic synthesis providing complex cyclic structures from easily available precursors [1][2]. Among

Synthesis, antiinflammatory activity, and molecular docking studies of bisphosphonic esters as potential MMP-8 and MMP-9 inhibitors

• Abimelek Cortes-Pacheco,
• María Adelina Jiménez-Arellanes,
• Francisco José Palacios-Can,
• José Antonio Valcarcel-Gamiño,
• Rodrigo Said Razo-Hernández,
• María del Carmen Juárez-Vázquez,
• Adolfo López-Torres and
• Oscar Abelardo Ramírez-Marroquín

Beilstein J. Org. Chem. 2020, 16, 1277–1287, doi:10.3762/bjoc.16.108

• a higher Pa value is desired. Thus, a Pa value of new bisphosphonates ≥ the Pa value of 1 and 2 was the applied inclusion criterion in this study. As can be seen in Figure 2, the Pa is greater for the new derivatives 3–6 (0.63–0.77) compared to the previous bioactive compounds 1 and 2 (0.51). In

• order to explore the SAR in the proposed compounds 3–6, we evaluated the effect of the volume of the ester group by the inclusion of ethyl or tert-butyl substituents in the aliphatic derivatives 3 and 4. On the other hand, the replacement of the aliphatic chains by an aromatic portion led us to the

• , Table 1). Nevertheless, the derivatives 3 and 4 exhibited a moderate antiinflammatory activity (25.5% and 23.9% edema inhibition, respectively). Thus, the inclusion of an aromatic ring in the derivatives 5 and 6 clearly potentiated the desired pharmacological effect on mice. The rationale behind this

A simple and easy to perform synthetic route to functionalized thienyl bicyclo[3.2.1]octadienes

• Dragana Vuk,
• Irena Škorić,
• Valentina Milašinović,
• Krešimir Molčanov and
• Željko Marinić

Beilstein J. Org. Chem. 2020, 16, 1092–1099, doi:10.3762/bjoc.16.96

• for biological testing. Conclusion From the two starting thiophene derivatives 1 and 2, ten novel products 3–12 have been prepared by a simple and low-cost procedure, paving the way to new researches, some of which could be directed toward inclusion of new heterocycles. Due to their indicative

Suzuki–Miyaura cross coupling is not an informative reaction to demonstrate the performance of new solvents

• James Sherwood

Beilstein J. Org. Chem. 2020, 16, 1001–1005, doi:10.3762/bjoc.16.89

• observed throughout unless noted subsequently. The first case study was adapted from that developed by Watson and co-workers [3][6]. The desired coupling is of 4-bromotoluene to produce 4-phenyltoluene, assisted by the inclusion of the bis(diphenylphosphino)ferrocene ligand and 3 equivalents of base

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

• containing these functional groups continues to increase, new synthetic pathways for their inclusion will surely attract synthetic organic chemists, as well challenge them to consider both existing approaches and developing new reactions. Many recent reviews already cover the syntheses and applications of

Design and synthesis of diazine-based panobinostat analogues for HDAC8 inhibition

• Sivaraman Balasubramaniam,
• Sajith Vijayan,
• Liam V. Goldman,
• Xavier A. May,
• Kyra Dodson,
• Sweta Adhikari,
• Fatima Rivas,
• Davita L. Watkins and
• Shana V. Stoddard

Beilstein J. Org. Chem. 2020, 16, 628–637, doi:10.3762/bjoc.16.59

• -rev is tilted downward forming a T-shaped π–π interaction with Phe-208. In review of the computational results, the inclusion of the nitrogen atoms in the core ring structure of panobinostat produced compounds with predicted binding affinities similar to panobinostat. Thus, aiming to develop improved

• inhibition results against HDAC8. Both of these inhibitors have pyrimidine rings in the core; thus, the data suggests that while this ring structure did produce inhibition, it was not as effective as the inclusion of a pyrazine ring. This finding is consistent with our computational data which demonstrated

Opening up connectivity between documents, structures and bioactivity

• Christopher Southan

Beilstein J. Org. Chem. 2020, 16, 596–606, doi:10.3762/bjoc.16.54

• of journal mandates for author inclusion of sequence accession numbers and somewhat later, pointers to genomic and expression data sets. This has needed herculean technical integration efforts not only from the NCBI Entrez system and the equivalent EBI resources but also global coordination by the

• . Thus, despite PubChem CIDs appearing in 2004 and the InChI identifier being implemented in 2013, publishers (with a few exceptions) have neither mandated nor encouraged the inclusion of open, machine readable chemical representations and/or open chemical database identifiers in their journals (external

Architecture and synthesis of P,N-heterocyclic phosphine ligands

• Wisdom A. Munzeiwa,
• Bernard Omondi and
• Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

• ] among other fields (Table 1). There is a number of review articles in the literature [9][10][11] which explore deeper into the applications of P,N-heterocyclic phosphine ligands. Besides, the inclusion of other heteroatoms in the phosphine ligand skeleton opens up many possibilities for metal

The interaction between cucurbit[8]uril and baicalein and the effect on baicalein properties

• Xiaodong Zhang,
• Jun Xie,
• Zhiling Xu,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 71–77, doi:10.3762/bjoc.16.9

• corresponding properties of the inclusion complex were studied using 1H NMR, IR and UV–vis spectroscopy and DTA. The results showed that BALE forms an inclusion compound (1:1) with Q[8], and the properties of baicalein are changed by cucurbit[8]uril. Keywords: baicalein; cucurbit[8]uril; host–guest interaction

• ; inclusion complex; properties; Introduction Baicalein (5,6,7-trihydroxyflavonoid) has a molecular formula of C15H10O5 (BALE, Figure 1) and is a natural flavonoid found in the roots of Scutellaria baicalensis Georgi [1]. The compound displays pharmacological activity such as antimicrobial, anti-inflammatory

• compounds such as calixarenes, crown ethers and cyclodextrins, which can be used to form a stable inclusion complex with the drug, and improving the bioavailability of the drug [34][35]. Herein, we describe the results of the investigations of host–guest interactions between BALE and Q[8] in an aqueous

Light-controllable dithienylethene-modified cyclic peptides: photoswitching the in vivo toxicity in zebrafish embryos

• Sergii Afonin,
• Oleg Babii,
• Aline Reuter,
• Volker Middel,
• Masanari Takamiya,
• Uwe Strähle,
• Igor V. Komarov and
• Anne S. Ulrich

Beilstein J. Org. Chem. 2020, 16, 39–49, doi:10.3762/bjoc.16.6

• require the inclusion of in vivo toxicity studies using vertebrate animal models. (For example, toxicity studies of anticancer chemotherapeutics are requested by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) to include at least two mammalian

Automated glycan assembly of arabinomannan oligosaccharides from Mycobacterium tuberculosis

• Alonso Pardo-Vargas,
• Priya Bharate,
• Martina Delbianco and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2019, 15, 2936–2940, doi:10.3762/bjoc.15.288

• incubation and reaction temperatures (from −20 °C to 0 °C) was introduced (procedure B). Capping after each glycosylation prevented the formation of undesired side products [26] and improved the isolated yield of 5 to 53%, with no detectable deletion sequences (Table 1). The inclusion of a capping step in

A combinatorial approach to improving the performance of azoarene photoswitches

• Joaquin Calbo,
• Aditya R. Thawani,
• Rosina S. L. Gibson,
• Andrew J. P. White and
• Matthew J. Fuchter

Beilstein J. Org. Chem. 2019, 15, 2753–2764, doi:10.3762/bjoc.15.266

• (Table 1). In contrast, chloro-substituted analogues present a significant decrease in the computed half-lives: 90 days for 4pzH-Cl1 and 5 days for 4pzH-Cl2. The inclusion of methoxy and pyrrolidine groups in the ortho-position leads to an enhanced Z-isomer thermal stability compared to unsubstituted

• 4pzH, with t1/2 = 2000 and 15000 days for 4pzH-OMe1 and 4pzH-OMe2, respectively, and 34000 days for 4pzH-Pyr1 (Table 1). Unexpectedly, the inclusion of two bulky pyrrolidine groups in ortho (4pzH-Pyr2) leads to a decrease in t1/2 (76 days). For the arylazopyrazole scaffold 4pzMe, in line with the trend

• compounds: the inclusion of one pyrrolidine group in the ortho-position (4pzH-Pyr1) is predicted to lead to a massively enhanced Z-isomer thermal stability (≈92 years), whereas two bulky pyrrolidine groups (4pzH-Pyr2) decrease stability, with a comparably modest t1/2 = 76 d (Table 1). Theoretical

Acid-catalyzed rearrangements in arenes: interconversions in the quaterphenyl series

• Sarah L. Skraba-Joiner,
• Carter J. Holt and
• Richard P. Johnson

Beilstein J. Org. Chem. 2019, 15, 2655–2663, doi:10.3762/bjoc.15.258

• . DFT computations with inclusion of implicit solvation support a complex network of phenyl and biphenyl shifts, with barriers to rearrangement in the range of 10–21 kcal/mol. Consistent with experiments, the lowest energy arenium ion located on this surface is due to protonation of m,p'-quaterphenyl

• potential energy surface. Protonation of a terminal phenyl group can also lead to terphenyl migration but this process is structurally degenerate and was not explored by computations. Both phenyl and biphenyl rearrangement pathways were studied by DFT methods, with inclusion of implicit solvation by the

• assessed by high field NMR analysis. Under these reaction conditions, m,p'-quaterphenyl (13) is the equilibrium product. This isomer is unchanged by the reaction conditions and all other quaterphenyl isomers rearrange to m,p' as the dominant or sole product. DFT computations with inclusion of implicit

In search of visible-light photoresponsive peptide nucleic acids (PNAs) for reversible control of DNA hybridization

• Lei Zhang,
• Greta Linden and
• Olalla Vázquez

Beilstein J. Org. Chem. 2019, 15, 2500–2508, doi:10.3762/bjoc.15.243

• cis-form did not show any decomposition under these conditions (Figure S27C, Supporting Information File 1), unlike when the oF4Azo was grafted onto a pyrrole scaffold [48]. Next, we explored if the inclusion of oF4Azo as monomer surrogate within the PNA sequence could affect its hybridization to a

Anion-driven encapsulation of cationic guests inside pyridine[4]arene dimers

• Anniina Kiesilä,
• Jani O. Moilanen,
• Anneli Kruve,
• Christoph A. Schalley,
• Perdita Barran and
• Elina Kalenius

Beilstein J. Org. Chem. 2019, 15, 2486–2492, doi:10.3762/bjoc.15.241

• could not be verified and the anions were assumed to interact with the pyridinearene cavity. Inclusion complexes of anions within pyridinearene dimers were also theoretically studied by DFT calculations, but using a truncated pyridinearene dimer model [8]. However, previous studies have also shown that

• as for [12 + H]+ (384.8 ± 0.41 Å2) and smaller than for the [12 + Na]+ complex, thus indicating inclusion complexation. This clearly indicates that the Me4N+ complex of 12 has the same rotation average diameter as the protonated dimer and thus the cation is encapsulated inside the cavity. Calculated

• ]arene dimer in [12 + PF6]− and the heterodimer [1·2 + PF6]−, but interestingly the abundance of [1·2 + PF6]− was half of [12 + PF6]−, and PF6− complexes with 2 or 22 had even lower abundances. This clearly shows that the anion has a higher affinity to pyridinearene than to resorcinarene. Inclusion

Reversible switching of arylazopyrazole within a metal–organic cage

• Anton I. Hanopolskyi,
• Soumen De,
• Michał J. Białek,
• Yael Diskin-Posner,
• Liat Avram,
• Moran Feller and
• Rafal Klajn

Beilstein J. Org. Chem. 2019, 15, 2398–2407, doi:10.3762/bjoc.15.232

• switching to the Z isomer was accompanied by the release of one of the two guests from the cage and the formation of a 1:1 cage/Z-arylazopyrazole inclusion complex. DFT calculations suggest that this process involves a dramatic change in the conformation of the cage. Back-isomerization was induced with

• green light and resulted in the initial 1:2 cage/E-arylazopyrazole complex. This back-isomerization reaction also proceeded in the dark, with a rate significantly higher than in the absence of the cage. Keywords: arylazopyrazoles; coordination cages; inclusion complexes; molecular switches

• on the prototypical arylazopyrazole 1 [35] (Scheme 1) and a previously reported [48] metal–organic cage 2 (see Figure 1). We have recently demonstrated that various azobenzenes formed 2:1 inclusion complexes with 2 [49] and hypothesized, based on the structural similarity between azobenzenes and

Morphology-tunable and pH-responsive supramolecular self-assemblies based on AB₂-type host–guest-conjugated amphiphilic molecules for controlled drug delivery

• Yang Bai,
• Cai-ping Liu,
• Di Chen,
• Long-hai Zhuo,
• Huai-tian Bu and
• Wei Tian

Beilstein J. Org. Chem. 2019, 15, 1925–1932, doi:10.3762/bjoc.15.188

• utilized as host units to construct these stimuli-responsive supramolecular self-assemblies [21][22][23][24][25][26][27]. For example, β-CD can form inclusion complexes with guests such as azobenzene [28][29], ferrocene [30][31] and benzimidazole [32][33][34] to construct light-, redox-, and pH-responsive

• was adjusted to 5.0, accompanied with morphology transitions from FSSAs to spherical self-assemblies (SSAs) due to the pH-induced dissociation of β-CD/BM inclusion complexes (Scheme 1c,d), and the hydrophilic–hydrophobic interaction-induced formation of spherical micelles with BM units as inner

• to BM protons in D2O was 3.75, which is slightly bigger than that of 3.46 in DMSO-d6 (Figure 2a) due to the shielding effect of host–guest inclusion. The proton peak ratios of 2,4,3,5,6-H protons of β-CD to BM protons in DCl/D2O was 24.96 (Figure 2c), which is bigger than that of the ratio of 3.75 in